What are the limiting factors involved in engine technology?
Specifically, I am wondering why we are still using big old engines. Just easier to work with what already works?

Development: First came gas otto cycle, then came diesel. Diesel is more efficient since the combustion is more complete due to the higher ignition temperatures. The major difference between gas and diesel (besides one uses gas and the other diesel) is in the compressed mixture and the igniting of the mixture. Gas mixes fuel and air at the carb or intake. The mixed fuel and air is compressed then ignited to preform the work of moving the piston which transfers the power to the crankshaft driving the flywheel, transmission, then wheels. Diesel draws air into the cylinder. The air is compressed raising the temperature of the air to over 400. Fuel is then sprayed into the cylinder where it instantaneously combusts. This process makes it possible to run the engine off vegetable oil. Von Diesel originally designed the engine so farmers could grow their own fuel(soybean oil).
Gas has won over diesel because until recently the diesel engine's higher compression ratios required a much thicker engine, making it much heavier, the power to weight ratio of the gas engine made it a much more attractive engine. However recent advances in materials has enabled light diesel engines(Golf TDI).

Inefficiencies of the engine: the transfer of power to the crankshaft and other parts, and this is the one that interests me the most LOSS OF HEAT

Why do we waste this heat? Can we not use the heat to create steam to drive turbines? Why use pistons at all? Why not just add fuel to an enclosed chamber (spherical) then ignite it. If the sphere was strong enough not to explode from the force would it not transfer the energy of the ignition into heat which could then be used to heat water driving a steam turbine. Locomotion would be accomplished by electric motors. What are the inefficiencies involed with electric motors?

Any thoughts? I realize the sphere would have to be able to blow off extreme pressure to prevent a possible explosion. Why is steam a bad idea?

What are the limiting factors involved in engine technology?
Specifically, I am wondering why we are still using big old engines. Just easier to work with what already works?

Development: First came gas otto cycle, then came diesel. Diesel is more efficient since the combustion is more complete due to the higher ignition temperatures. The major difference between gas and diesel (besides one uses gas and the other diesel) is in the compressed mixture and the igniting of the mixture. Gas mixes fuel and air at the carb or intake. The mixed fuel and air is compressed then ignited to preform the work of moving the piston which transfers the power to the crankshaft driving the flywheel, transmission, then wheels. Diesel draws air into the cylinder. The air is compressed raising the temperature of the air to over 400. Fuel is then sprayed into the cylinder where it instantaneously combusts. This process makes it possible to run the engine off vegetable oil. Von Diesel originally designed the engine so farmers could grow their own fuel(soybean oil).
Gas has won over diesel because until recently the diesel engine's higher compression ratios required a much thicker engine, making it much heavier, the power to weight ratio of the gas engine made it a much more attractive engine. However recent advances in materials has enabled light diesel engines(Golf TDI).

Inefficiencies of the engine: the transfer of power to the crankshaft and other parts, and this is the one that interests me the most LOSS OF HEAT

Why do we waste this heat? Can we not use the heat to create steam to drive turbines? Why use pistons at all? Why not just add fuel to an enclosed chamber (spherical) then ignite it. If the sphere was strong enough not to explode from the force would it not transfer the energy of the ignition into heat which could then be used to heat water driving a steam turbine. Locomotion would be accomplished by electric motors. What are the inefficiencies involed with electric motors?

Any thoughts? I realize the sphere would have to be able to blow off extreme pressure to prevent a possible explosion. Why is steam a bad idea?

First, just a couple of misconceptions to rectify. Diesel didn't design his engine to run on soybean oil, there was no such thing in 1893. It was peanut oil. And he didn't complete all the basic innovations of the device, that was a fellow named Charles Kettering.

There have been attempts at making practical turbine engines for cars but without a great deal of success. But those were gas (or oil-fired as in aircraft engines) and not steam as you suggest. The problem with a steam turbine is that there is still a tremendous amount of heat that has to be somehow rejected. Unless you want to stop every 50 miles or so and refill with water. And carrying around all that heavy water is tough on fuel economy as well.

You probably aren't aware of the inherent losses that occur every time you go through an energy conversion. Your steam-driven electric motors actually have several of them and each one costs. They are: Chemical > mechanical (boiler/turbine), mechanical > electrical (generator or alternator), and finally electrical > mechanical (electric motors).

Even the new hybrid cars pay a penalty for the power conversions but they minimize the losses by having the gasoline engine operate all the time at the peak efficiency of it's power curve. That is impossible to do from a practical standpoint with any sort of turbine - unless it is very, very small. A very tiny one might make it practical but would lack the acceleration needed at certain times in driving.

A tiny turbine... hmmm now that sounds interesting.

During World War 2 the germans were developing a diesel which used the exhaust to drive an integral turbine. It was a mechanical nightmare. Many, many parts.

Any machine suffers wear on all its moving parts. The designer/manufacturer must strike an acceptable balance: a simple machine might have less fuel economy but have fewer breakdowns, whereas a complex machine may gain economy but be unreliable.

A large factor in diesel economy in vehicles is volumetric efficiency. They do not have throttle plates, therefore airflow is never restricted. Compared to gasoline engines, diesels waste less work drawing in air.

A major consideration is the limitations of materials. How high a temp can the pistons/sleaves/cylinderheads, turbine/combustionchamber, etc., stand before the mechanical properties go to pot. This limits the Carnot efficeincy of almost all heat engines, as most materials with acceptable wear/strength characteristics can't stand more than 300 or 400 F.

First, just a couple of misconceptions to rectify. Diesel didn't design his engine to run on soybean oil, there was no such thing in 1893. It was peanut oil. And he didn't complete all the basic innovations of the device, which was a fellow named Charles Kettering.

Thank you for the clarification, it has been awhile since I looked it up. Kind of funny since the number one agricultural product in the state I live in, Georgia, is peanutsJ


There have been attempts at making practical turbine engines for cars but without a great deal of success. But those were gas (or oil-fired as in aircraft engines) and not steam as you suggest. The problem with a steam turbine is that there is still a tremendous amount of heat that has to be somehow rejected. Unless you want to stop every 50 miles or so and refill with water. And carrying around all that heavy water is tough on fuel economy as well.

I was thinking of recycling the fluid and it would not have to be water. A fluid with a really low boiling point would be better. The condenser could use forced air from the front of the vehicle for any cooling necessary, since air temp is almost always below 100 Fahrenheit. However, the design would need to conserve as much heat as possible, perhaps using the steam after it has started to cool to start the heating of fluid before it is drawn into the engine fluid jackets encircling the block.


You probably aren't aware of the inherent losses that occur every time you go through an energy conversion. Your steam-driven electric motors actually have several of them and each one costs. They are: Chemical > mechanical (boiler/turbine), mechanical > electrical (generator or alternator), and finally electrical > mechanical (electric motors)..

Aware, but ignorant of how the loses in energy compare to each other, which is why I posted. Not sure how efficient electric motors are, but I know the current combustion engine is very inefficient, along the lines of twenty percent or so. Thinking of energy out compared to the potential energy of the fuel.

The combustion energy seems to loose a lot of energy to friction between moving parts. The smaller the number of parts the greater the efficiency. I believe a majority of the loss is from the loss of heat energy.

What I am really unsure about is if a small explosion can be harnessed and converted into heat efficiently.


Even the new hybrid cars pay a penalty for the power conversions but they minimize the losses by having the gasoline engine operate all the time at the peak efficiency of its power curve. That is impossible to do from a practical standpoint with any sort of turbine - unless it is very, very small. A very tiny one might make it practical but would lack the acceleration needed at certain times in driving.

The turbine could operate at a constant power output. The turbine would be directly connected to the alternator/generator. A design problem would be what to do with the power you do not need. I say this because the turbine would have a maximum efficiency speed of operation and you would want it to only operate when necessary. Perhaps buffering the power to large capacitors for storage. They already do that in some hybrids don’t they?

Using a turbine hybrid instead of gas combustion hybrid.

The efficiency gained by the gas combustion hybrid by operating it at peak efficiency is achieved by eliminating the transmission. Shifting gears necessitated the disengagement of the engine, which decelerates the engine below optimum efficiency. I would not want a transmission either.

Lack of acceleration, makes me think of the differences between common combustion engine and the Wankel rotary engine. The Wankel gains efficiency because it operates around a central axis eliminating the up and down power conversion in the common combustion engine. However, Wankel engines lack the torque of the common combustion engine because it does not take advantage of the elasticity of air, the compressed explosion makes more torque. Wankel makes more horsepower but less torque.

Tirstan: in piston engines a "square" bore/stroke ratio is popular. This a where the bore and stroke are the same: such as 3" bore and 3" stroke. The corresponding area of a 3" tall cylinder and its 3" diameter head are the radiative areas which lose heat which could otherwise perform work, but which also protect the engine by transferring excess heat into coolant.

Sketch a few cylinders of different size but with the same square proportion. Calculate the internal volume of each one. The volume is the amount of working fluid which moves the piston. Then calculate the radiative area of each one. Finally compare the volume to the area of each one. Now you can judge the way in which a larger or smaller motor will have advantage in keeping heat in the working fluid or losing it by radiation.

Electric motors are often claimed by an optimistic manufacturer to be 90 % or higher. There are skeptics who claim that it is unusual to get over 40 % with varying loads.

Thank you for the clarification, it has been awhile since I looked it up. Kind of funny since the number one agricultural product in the state I live in, Georgia, is peanutsJ

Well, you're close. :) According to the USDA, peanuts are a distant third with 7% of the agricultural income for the state. They follow broilers at 44% and cotton at 10%. ;)



I was thinking of recycling the fluid and it would not have to be water. A fluid with a really low boiling point would be better. The condenser could use forced air from the front of the vehicle for any cooling necessary, since air temp is almost always below 100 Fahrenheit. However, the design would need to conserve as much heat as possible, perhaps using the steam after it has started to cool to start the heating of fluid before it is drawn into the engine fluid jackets encircling the block.

Cooling is absolutely essential. A heat engine cannot even come close to being efficent unless it is able to reject heat very, very quickly.

Aware, but ignorant of how the loses in energy compare to each other, which is why I posted. Not sure how efficient electric motors are, but I know the current combustion engine is very inefficient, along the lines of twenty percent or so. Thinking of energy out compared to the potential energy of the fuel.

The efficency of electric motors will average around 38% with varying loads, such as driving. Each of those stages of energy conversion I listed before will cost about 15 - 22% each, again, depending on loading. You've already mentioned the "cost" of the major one - converting fuel into mechanical motion. I'm pretty sure you're following but in case someone else doesn't quite catch it, you don't simply add all those losses together because they would quickly exceed 100%. :D They are interstage losses and must be subtracted incrementally to get the real numbers.

The combustion energy seems to loose a lot of energy to friction between moving parts. The smaller the number of parts the greater the efficiency. I believe a majority of the loss is from the loss of heat energy. You are correct about heat losses. That's about 70% in a gasoline engine while friction is about 5% and inertial losses (such as reversing the direction of piston movement) is about another 5%.

What I am really unsure about is if a small explosion can be harnessed and converted into heat efficiently.

Not quite sure I follow this because the conversion to heat is close to 100%. I suspect you really mean converted to usable energy and that's what we're discussing.


The turbine could operate at a constant power output. The turbine would be directly connected to the alternator/generator. A design problem would be what to do with the power you do not need. I say this because the turbine would have a maximum efficiency speed of operation and you would want it to only operate when necessary. Perhaps buffering the power to large capacitors for storage. They already do that in some hybrids don’t they?

Direct-drive is certainly best. No, capacitors aren't useful for energy storage beyond a couple of minutes. For one thing, they have VERY limited capacity and are also prone to leakage, even with the best design. Battery storage is the only thing practical right now. Flywheel storage once looked promising but brings with it another whole new set of challenges.

Using a turbine hybrid instead of gas combustion hybrid.

The efficiency gained by the gas combustion hybrid by operating it at peak efficiency is achieved by eliminating the transmission. Shifting gears necessitated the disengagement of the engine, which decelerates the engine below optimum efficiency. I would not want a transmission either.

That's true but there is a little more to it. Every engine has an optimal speed for maximum output power. Any slower or faster costs efficency.

Lack of acceleration, makes me think of the differences between common combustion engine and the Wankel rotary engine. The Wankel gains efficiency because it operates around a central axis eliminating the up and down power conversion in the common combustion engine. However, Wankel engines lack the torque of the common combustion engine because it does not take advantage of the elasticity of air, the compressed explosion makes more torque. Wankel makes more horsepower but less torque.

Wankels can produce impressive acceleration. I believe that perhaps you are actually thinking of the Stirling engine? Very efficent (as engines go) but with horrible acceleration capabilities.

Well, you're close. :) According to the USDA, peanuts are a distant third with 7% of the agricultural income for the state. They follow broilers at 44% and cotton at 10%. ;)


Georgia produces 42% of the entire peanut crop in the US.
75% is converted into peanut butter.

http://resources.caes.uga.edu/media/GAR/peanuts.htm


kindof busy lately I'll write more soon

Georgia produces 42% of the entire peanut crop in the US.
75% is converted into peanut butter.

http://resources.caes.uga.edu/media/GAR/peanuts.htm


kindof busy lately I'll write more soon

Yes, that's true but it doesn't match you original statement. ;)

" ...since the number one agricultural product in the state I live in, Georgia, is peanutsJ " (Emphasis mine.)

(See what I mean?) :)

I think that the Carnot equation only says that you can't get more heat out of an engine than you put into it.

Stirling engines really need something like a flywheel and a starter motor. Then they can act as if resonant over a fair range of thrust and rpms and be kicked into their proper operating range instead of waiting for random chance to get them cycling. I think that Stirling engines, when used right, may be about the most efficient engines. I've read of models that can actually ice up, which tells me that they may be able to exceed Carnot efficiency by acting like a heat pump.

I think that the Carnot equation only says that you can't get more heat out of an engine than you put into it.

Stirling engines really need something like a flywheel and a starter motor. Then they can act as if resonant over a fair range of thrust and rpms and be kicked into their proper operating range instead of waiting for random chance to get them cycling. I think that Stirling engines, when used right, may be about the most efficient engines. I've read of models that can actually ice up, which tells me that they may be able to exceed Carnot efficiency by acting like a heat pump.

Wow! You'd better go back and do some more reading. The first part is just basic, simple thermodynamics and the last paragraph is totally wrong expert for the part about the efficency. (And that's still debatable since a turbine is the most efficient of all but that's a rather different class.)

Stirling engines are low temperature differential engines and are assumed to be less efficient because they are labelled according to Carnot efficiency. I've done my reading. The Carnot equation reveals nothing more and nothing less than the percentage difference between two temperatures on either the Kelvin or the Rankine scale. It's like saying that if you have water at 300 degrees K and lower its temperature to 270 degrees K by extracting useful energy out of it, you are only 10 percent efficient. But if that 300 K water started out at 270 K, and you used something like a solar panel to raise it to 300 K, and you lower it back to 270 K, you have no way of knowing your efficiency unless you compare the useful energy you got out of the water with the the energy you put into it. There's thirty calories per gram of hot water there, how many watt-seconds did you get out of each gram?

The turbine is assumed to be more efficient because it operates at a higher temperature. I don't believe in this assumption.

I was thinking about the diaphragm type of Stirling engine and had to review a little because there are piston types. I don't think I said a thing that is wrong in that paragraph because at least some Stirling engines aren't very good at self-starting and even a lightweight flywheel helps the engine run at an even pace. Some of the more popular recent designs use diaphragms because they are easier to make and don't have to slide up and down cylinders. I am pretty certain that these designs can be improved for greater power and efficiency if they don't have to start themselves, because most improvements would require a certain amount of force to get the cycle started.

Stirling engines are low temperature differential engines and are assumed to be less efficient because they are labelled according to Carnot efficiency. I've done my reading. The Carnot equation reveals nothing more and nothing less than the percentage difference between two temperatures on either the Kelvin or the Rankine scale. It's like saying that if you have water at 300 degrees K and lower its temperature to 270 degrees K by extracting useful energy out of it, you are only 10 percent efficient. But if that 300 K water started out at 270 K, and you used something like a solar panel to raise it to 300 K, and you lower it back to 270 K, you have no way of knowing your efficiency unless you compare the useful energy you got out of the water with the the energy you put into it. There's thirty calories per gram of hot water there, how many watt-seconds did you get out of each gram?

The turbine is assumed to be more efficient because it operates at a higher temperature. I don't believe in this assumption.

I was thinking about the diaphragm type of Stirling engine and had to review a little because there are piston types. I don't think I said a thing that is wrong in that paragraph because at least some Stirling engines aren't very good at self-starting and even a lightweight flywheel helps the engine run at an even pace. Some of the more popular recent designs use diaphragms because they are easier to make and don't have to slide up and down cylinders. I am pretty certain that these designs can be improved for greater power and efficiency if they don't have to start themselves, because most improvements would require a certain amount of force to get the cycle started.

Yes, yes, MetaKron. I believe everyone realizes that it's temperature differential that makes any engine work. It's all about transforming chemical energy into heat and converting that into mechanical motion.

As to turbines, they ARE more efficient - no assumptions as you claim. Their energy in vs power output is easily measured. It's just you making a silly assumption - not all the power engineers in the world. {heavy sigh!} You still need to do a LOT more serious study to prevent embarrassing yourself so badly. You do yourself a disservice by talking about things you know too little about.

Light, you still need to grow up a little.

Light, you still need to grow up a little.

Sorry, but that actually applies to you. I've had considerably more experience with engines of many types and with all sorts of engineers as well. Exactly how much have you had at your young age? I'm guessing from the general tone of all your posts that you are probably still in school and are just going by what you think you know. A few more years of living will teach you a lot.

Trouble is, Light, you are way too overbearing when you want to "explain" something to people. If a little courtesy would cost you your life or your job, by all means, take the chance.

Trouble is, Light, you are way too overbearing when you want to "explain" something to people. If a little courtesy would cost you your life or your job, by all means, take the chance.

Hmmmm....

Here's the thing. I spent many years as a teacher (professor in college) and that's probably why you view me in the way you do. The biggest problem any teacher has is dealing with people who think they know something when actually they are totally incorrect. There's a lot more to teaching than just presenting facts. Trying to get people to unlearn their "facts" and look at things logically and accurately can often be a major task.

And that's what I see a lot of here. People like myself trying to correct the mis-thinking of others - like your assumptions about turbines. You were right about a part of it but didn't even know why. They DO operate at higher temperatures - and all engines that operate at higher temps usually ARE more efficient than those that are working at lower temperatures.

But the thing is that people who know a little about something (like you and the Carnot cycle) try to use fancy words and terms like that to fool others into thinking that they know more than they really do. But the end result is they wind up looking very foolish and loose what they were after in the first place - the respect of others. Anyone who tries to fake knowledge always winds up the looser.

You probably think all I just said was overbearing as well. So be it - welcome to the real world of adults.

To paraphrase a famous author: "The real world is a harsh mistress.".

To paraphrase a famous author: "The real world is a harsh mistress.".

Indeed!!

(Well noted, CANGAS.)

Light, one of your nicknames is "that a$$hole", isn't it? You have all that teaching experience and you don't know how to take the high road or how to quit when ahead. Maybe you need more teaching experience. There are some community colleges in western Kansas where you might be able to round yourself out.

You went over the line when you accused me of trying to look like I knew more than I did when I honestly expressed an opinion. Frankly, I don't care so much what you think of me, but I don't think you're particularly honest and I do think you're way too overbearing.

Light, one of your nicknames is "that a$$hole", isn't it? You have all that teaching experience and you don't know how to take the high road or how to quit when ahead. Maybe you need more teaching experience. There are some community colleges in western Kansas where you might be able to round yourself out.

You went over the line when you accused me of trying to look like I knew more than I did when I honestly expressed an opinion. Frankly, I don't care so much what you think of me, but I don't think you're particularly honest and I do think you're way too overbearing.

Quite frankly, kid, I don't give a hoot what you think of me. And your "honest opinion", as you claim, was stated as fact - not opinion!!

I am and always will be perfectly honest at all times. And here's a little more honesty for you - I don't care if you go down in the flames of ignorance. You aren't one of my students and I've seen a few much smarter than you fail completely. Sorry, but that just another dose of real life for you. The fact that most of us aren't one bit interested in what becomes of you or what you think of us. It won't affect my bank account one way or the other. :D

Yes, Light, every jerk who acts the way you've been acting always thinks that it's justified and they all have their own line of doubletalk. All you're doing is taking potshots.

Do you have any kind of test of whether Carnot efficiency is the limit of the efficiency of a heat engine? They always say "don't assume." Do we believe this thing because of actual experiment or untested theory? Are people even allowed to advertise that an engine exceeds Carnot efficiency when in fact it does? And while we're at it, why does it seem so clear that a heat pump is more efficient than resistance heating when it is supposed to take more energy to pump heat uphill than to just generate the heat? It sounds like doubletalk to me.

Yes, Light, every jerk who acts the way you've been acting always thinks that it's justified and they all have their own line of doubletalk. All you're doing is taking potshots.

Do you have any kind of test of whether Carnot efficiency is the limit of the efficiency of a heat engine? They always say "don't assume." Do we believe this thing because of actual experiment or untested theory? Are people even allowed to advertise that an engine exceeds Carnot efficiency when in fact it does? And while we're at it, why does it seem so clear that a heat pump is more efficient than resistance heating when it is supposed to take more energy to pump heat uphill than to just generate the heat? It sounds like doubletalk to me.

Sigh.

You really don't know much about mechanics, do you?

Just do even the tiniest bit of research on heat pumps and the answer will jump right out at you! It's because they use that energy to extract the heat form an external source (air or water) and concentrate the heat delivered. Have you ever heard of the term "Coefficient Of Performance?" It's a direct measurement of the energy supplied to the amount delivered. In the case of a heat pump, the COP will easily run 3.0 to 4.0. That means for every watt of electrical energy supplied to the pump - for which you'd only get a single watt of heat in a resistance heater - there's actually three or four watts of heat delivered at the output. Doubletalk? Hardly.

You really, really, really need to study more before you even open your mouth again. You just keep digging yourself in deeper.

Sigh.

You really don't know much about mechanics, do you?

Just do even the tiniest bit of research on heat pumps and the answer will jump right out at you! It's because they use that energy to extract the heat form an external source (air or water) and concentrate the heat delivered. Have you ever heard of the term "Coefficient Of Performance?" It's a direct measurement of the energy supplied to the amount delivered. In the case of a heat pump, the COP will easily run 3.0 to 4.0. That means for every watt of electrical energy supplied to the pump - for which you'd only get a single watt of heat in a resistance heater - there's actually three or four watts of heat delivered at the output. Doubletalk? Hardly.


So you are saying that heat pumps deliver far more than unity gain, even counting losses in the cycle. You said in exactly that many words that a machine that is on the market uses one watt to move up to four watts of heat uphill. I think it's doubletalk. It violates physical laws that you would use to claim that there is no way to use ambient heat to generate useful energy and that Carnot efficiency is the end of the story. Prove your claim.

What are the limiting factors involved in engine technology?
Specifically, I am wondering why we are still using big old engines. Just easier to work with what already works?

Development: First came gas otto cycle, then came diesel. Diesel is more efficient since the combustion is more complete due to the higher ignition temperatures. The major difference between gas and diesel (besides one uses gas and the other diesel) is in the compressed mixture and the igniting of the mixture. Gas mixes fuel and air at the carb or intake. The mixed fuel and air is compressed then ignited to preform the work of moving the piston which transfers the power to the crankshaft driving the flywheel, transmission, then wheels. Diesel draws air into the cylinder. The air is compressed raising the temperature of the air to over 400. Fuel is then sprayed into the cylinder where it instantaneously combusts. This process makes it possible to run the engine off vegetable oil. Von Diesel originally designed the engine so farmers could grow their own fuel(soybean oil).
Gas has won over diesel because until recently the diesel engine's higher compression ratios required a much thicker engine, making it much heavier, the power to weight ratio of the gas engine made it a much more attractive engine. However recent advances in materials has enabled light diesel engines(Golf TDI).

Inefficiencies of the engine: the transfer of power to the crankshaft and other parts, and this is the one that interests me the most LOSS OF HEAT

Why do we waste this heat? Can we not use the heat to create steam to drive turbines? Why use pistons at all? Why not just add fuel to an enclosed chamber (spherical) then ignite it. If the sphere was strong enough not to explode from the force would it not transfer the energy of the ignition into heat which could then be used to heat water driving a steam turbine. Locomotion would be accomplished by electric motors. What are the inefficiencies involed with electric motors?

Any thoughts? I realize the sphere would have to be able to blow off extreme pressure to prevent a possible explosion. Why is steam a bad idea?


A lot of the reason we waste heat from a gasoline engine is because recovering it and using it requires bulky, expensive, and complex equipment. We are better off throwing it away than we are adding that much more gear to the inside of the engine compartment. Even scavenging fuel vapors from the exhaust is fairly hard to do and it adds one more risk factor to the use of gasoline engines.

So you are saying that heat pumps deliver far more than unity gain, even counting losses in the cycle. You said in exactly that many words that a machine that is on the market uses one watt to move up to four watts of heat uphill. I think it's doubletalk. It violates physical laws that you would use to claim that there is no way to use ambient heat to generate useful energy and that Carnot efficiency is the end of the story. Prove your claim.

Good grief - it's not my claim! How can you be so silly? They have been marketed for years because they work so well at saving energy. I've even installed one of them myself - actually did all the work with the help of one other fellow.

As I've said to you several times already, you need to actually READ before you speak! Here's a brief (so it won't kill your short attention span) article that even explains the math involved (but you'll probably have to get some one to explain the math to you). http://en.wikipedia.org/wiki/Heat_pumps

Tell you what, I'll make a deal with you. If you'll restrict yourself to just asking questions - and thereby actually learn something (maybe!) instead of trying to act so "smart" (and completely blowing it), I'll get off your case and be one of those that provides you with straight and honest answers. Deal?

It's doubletalk. It is impossible to push energy uphill without expending more energy than you move. Also, you forgot to link to the article you promised. OK, I see it now. Wasn't there before.

It's doubletalk. It is impossible to push energy uphill without expending more energy than you move. Also, you forgot to link to the article you promised. OK, I see it now. Wasn't there before.

Yes, I accidentally posted it before including the link but corrected it quickly.

After you've read it, come back and tell us what you've learned.

Light, the article you linked me to entirely fails to explain how a heat pump produces any advantage over resistance heating. The mathematics in the article are only good for estimating the COP from observed hot side and cold side temperatures and nothing else. The fact that a heat pump compresses a working fluid is a given. You need to supply more information if you expect a person to understand or even believe a COP greater than one.

I have doctrine firmly behind me on this one. Because of the laws of thermodynamics, I have to presume that compressing the working fluid takes as much energy as we can "extract" from that same working fluid. The volume does not change because we pour it into a taller, narrower vessel.

Did you actually read the article, Light?

And furthermore, on top of that: The math in the Wiki article does not include any proof that it can be legitimately used to estimate COP because it does not include any value for the actual work expended to raise or lower the temperature of the working fluid. Try again, Light.

The one over the Carnot cycle efficiency is priceless. Carnot efficiency is never greater than one, so one over that number is never less than one. All you have to do to get overunity is to turn the equation upside down. How come I never thought of that?

I think you've given me something useful here but I don't know if it is something I can use, and if I can use it I don't know that it won't get me shot.

Light, the article you linked me to entirely fails to explain how a heat pump produces any advantage over resistance heating. The mathematics in the article are only good for estimating the COP from observed hot side and cold side temperatures and nothing else. The fact that a heat pump compresses a working fluid is a given. You need to supply more information if you expect a person to understand or even believe a COP greater than one.

I have doctrine firmly behind me on this one. Because of the laws of thermodynamics, I have to presume that compressing the working fluid takes as much energy as we can "extract" from that same working fluid. The volume does not change because we pour it into a taller, narrower vessel.

Did you actually read the article, Light?

Yes, I read it.

I must say that I've run across a few boneheads in my 60+ years but never one that seemed to want to make a career out it as you seem to.

The fact that they've been selling these things for over forty years doesn't even give you clue??? Do you somehow think that all those millions of people, businesses and industries were tricked into buying something that didn't even work as it was claimed???

Man! After reading this and your next post, I'll have to downgrade your status to something considerably less than just "dummy!" That term is far to generous for you.

Thing is, there are several other people here who also know exactly how heat pumps work. As soon as they read what you've said they will all be laughing their heads of at you! What a dope! :D

Like I said, Light, it looks like you have you some growing up to do.

Like I said, Light, it looks like you have you some growing up to do.
Ha-hah-ha!

Hardly - look who's talking!

Just how old are you, anyway? Maybe 15 at the most? And don't say it doesn't matter because it really does. At that age or less, we can understand. But if it's over that, well...

I understood the mathematics quite well. It would have helped if someone had explained that the "A" stood for the amount of energy input into the heatpump, presumably the portion that is power supplied by the user to push the heat around. The thing is, you still have the Carnot equation upside-down and you don't blink an eye when it gives upside-down results. The equation in that page you linked to cannot give any result less than 1. It cannot give an output to input ratio of less than one. All of this is quite explicit. You have no call to call me "dummy." I don't know what planet you live on where you think that is appropriate.

So what we have here is "Light" telling me that you can get 4 watts of heat out of a heat pump per watt that you supply as power, and that this is because of the mathematics at this Wikipedia page. (http://en.wikipedia.org/wiki/Heat_pumps) Then he calls me a dummy because I point out what is glaringly obvious. Here is the Carnot Equation (scan down the page) (http://en.wikipedia.org/wiki/Carnot_heat_engine) for comparison.

The mathematics describe a situation that is exactly as if a heat engine that is 25 percent efficient at producing mechanical energy will, if reversed, become 400 percent efficient at transporting heat energy uphill by applying mechanical energy. It is exactly what Light has claimed, and the entire industry claims. It satisfies a type of mathematical symmetry. It is also impossible according to the laws of thermodynamics. It is supposed to take at least as much work to push a given number of BTUs uphill as you would get out of those BTUs, no exceptions. If someone wants to challenge that, please do. It is supposed to be one of those crackpot claims that no one is ever supposed to believe, that you can use some kind of tricks to get heat to go uphill without expending a lot of excess energy. So, in theory it can't work at all. Experimental evidence shows that it does work. This is what I've been trying to get at all night.

Here's another little tidbit for you to think about. Do you also suppose it takes more electricity (energy) to pump gasoline/petrol from the tank in the ground up into your car than you get from the fuel when you drive your car?

It's very similar in that the heat pump expends energy gathering additional energy and pumping it indoors. A very large portion of the energy used by the pump is simply lost - but it more than makes up for that with what it collects from the surrounding air or water.

The environment actually contains a LOT of heat, just at a lower intensity. The heat pump collects and concentrates that. Your mistake is that you are apparently supposing that the claim is that you put electrical power into the unit and it somehow "magically" is producing more than you supplied. And that's not the situation at all - it has a tremendous reservoir of external heat to draw upon.

But I suppose you won't understand that either, eh? :rolleyes:

It doesn't matter what size the tremendous reservoir is. That's a fallacy used by people who promote obvious violations of the 2nd law. The analogy of the gasoline pump is a false analogy. You're making the same claims that a lot of the promoters of perpetual motion make. The fact that these claims seem to be testable and true doesn't change their content.

I understand that when I want to build a heat engine using hot water I am told that I can't turn even a substantial percentage of the heat energy in that water into mechanical energy. Then I'm told that it's exactly backwards with heat pumps. That's what the equations say. The Carnot equation says that you can't get more than unity. The heat pump equation says that you can't get less than unity. Experimental evidence says that you can get at least four times unity.

How about facing down the equations and the evidence? Try not to call names.

Again: The objection to super-efficient heat engines is that you can't get more than the Carnot efficiency. No matter how large your reservoir is, it is only so deep.

I understood the mathematics quite well. It would have helped if someone had explained that the "A" stood for the amount of energy input into the heatpump, presumably the portion that is power supplied by the user to push the heat around. The thing is, you still have the Carnot equation upside-down and you don't blink an eye when it gives upside-down results. The equation in that page you linked to cannot give any result less than 1. It cannot give an output to input ratio of less than one. All of this is quite explicit. You have no call to call me "dummy." I don't know what planet you live on where you think that is appropriate.

So what we have here is "Light" telling me that you can get 4 watts of heat out of a heat pump per watt that you supply as power, and that this is because of the mathematics at this Wikipedia page. (http://en.wikipedia.org/wiki/Heat_pumps) Then he calls me a dummy because I point out what is glaringly obvious. Here is the Carnot Equation (scan down the page) (http://en.wikipedia.org/wiki/Carnot_heat_engine) for comparison.

The mathematics describe a situation that is exactly as if a heat engine that is 25 percent efficient at producing mechanical energy will, if reversed, become 400 percent efficient at transporting heat energy uphill by applying mechanical energy. It is exactly what Light has claimed, and the entire industry claims. It satisfies a type of mathematical symmetry. It is also impossible according to the laws of thermodynamics. It is supposed to take at least as much work to push a given number of BTUs uphill as you would get out of those BTUs, no exceptions. If someone wants to challenge that, please do. It is supposed to be one of those crackpot claims that no one is ever supposed to believe, that you can use some kind of tricks to get heat to go uphill without expending a lot of excess energy. So, in theory it can't work at all. Experimental evidence shows that it does work. This is what I've been trying to get at all night.

No. At this point I've had quite enough tonight of your unwillingness to learn. I may return later but in the meanwhile someone else can try cramming real information into your dense head. You think you know the answers? Fine - live with them.

And since you didn't see fit to reveal your age, I gather you're just a stupid know-nothing young punk. Not worth wasting my efforts on.

Goodnight.

You know, Light, you have entirely failed to make it believable tonight. I don't think that anyone over the age of 15 is falling for it, even after you've broken your chalk and thrown the eraser to the back of the room.

Wikipedia article (http://en.wikipedia.org/wiki/Carnot_heat_engine)


The way it's always been explained to me, if the Carnot formula says the engine efficiency is 10 percent, that means that the engine produces a power output that is equivalent to 10 percent of the energy that is available. The energy that is available is proportionate to the difference between the Kelvin temperatures of the hot side of the engine and the ambient temperature. So I've been told that such a setup gives me 10 percent of that ten percent. The general presumption is that you would start with a working fluid like water at ambient temperature, raise its temperature using some kind of heat source, and convert that heat to other kinds of energy like mechanical energy or electricity. The only heat that is available is that part that is above the ambient temperature. If your hot side is 330 K and your ambient is 297k, only ten percent of the hotside temperature, the hotside heat content, is available. The Carnot equation expresses efficiency as a percentage of the hotside temperature, and it does say hotside over ambient. Your engine can use all of the available heat and still be rated at 10 percent efficiency by that standard. The maximum possible utilization of the heat energy is rated at 10 percent instead of 100 percent heat efficiency. Then they tell you to only expect 10 percent of that 10 percent, so the best heat engines theoretically possible can allegedly only give you one watt of work for every ten watts of heat put into them.

I don't know. I always felt like if an engine used all of the energy available to it, it worked at 100 percent efficiency, giving ten watts of work for ten watts of heat input, and so on. I've also always felt like the only energy available from a heat source was in that part that was more than the ambient temperature.

How about having a vessel (cargo-carrier, for instance, of any kind) with a central engine core that runs the entire length of the ship. Line up a whole lot of turbines, and have water intakes leading in from the sides infront of each one of them (like the air intakes of jet engines). That way, you avoid the problem of having diminishing power to each successive turbine. With the same amount of water passing through each turbine, the power output would be the same at each stage. Now I'm not an engineer, and there are sure to be problems with that seemingly simple idea--let me know if there are. :)

Where does each turbine exhaust relative to the next turbine in line?

The turbine exhausts are at 90 degrees to the next set of turbine intakes.

MetaKron,

While Light may be a bit beligerant, he's right and you're certainly confused on this heat pump issue. The coefficient of performance (CP) is a ratio of the energy transferred for heating to the work (electrical energy used by the pump in this case) put into the cycle. Because you're getting energy from the environment this will be a number > 1.

CP is NOT a typical efficiency in the sense that it is calculated by energy-out/energy-in because we only consider the energy put into the pump as the "energy in", but we are getting energy "in" to the sytem through the transfer from the low temperature reservoir.

This is basic thermodynamics and these things exist (and work) all over the place in the real world. In fact your refrigerator is working on the same principle.

Hey, Flunch, if experimental evidence shows that it works, then I believe that it does work. It's still against the law, physical law that is. Just because it comes from a larger reservoir is meaningless when that larger reservoir is lower. This would be like saying that you experience a net gain in usable energy by pumping water from Lake Pontchatrain to a water tower because the lake is larger than the water tower.

No one has claimed to me or shown me test results that say that it takes less energy to move heat out of my refrigerator than is actually removed. I would give those results a lot of crediblity especially if the testers provided raw data and testing criteria. I will always give more credibility to experimental results than to anyone's guesses as to what the results will be.

Light couldn't explain the setup for whatever reason. Getting belligerent because you can't explain something is of course your choice, but it doesn't get any explaining done. What is clear from the Wiki articles, which I will go with for now, is that there is a number for the energy that is input into the system, and there is a number for the energy that you get out of the system. According to the laws of thermodynamics we can't get more energy out than we put in, and we can't move a given amount of heat uphill without expending that much energy to move it. Even when you conserve your investment in energy, you can only get a COP of a bit less than 2. The energy you put in pushes its own weight in heat minus losses, and is itself converted to heat. Maybe more than one, definitely less than 2.

A heat pump or any other device cannot be an isolated case of a violation of the 2nd law of thermodynamics. If there is one strong example of such a violation, that law is broken. We need to reinterpret our physical theory to take observed facts into account.

What? :bugeye:

What?

You say that if actual results disprove theory then we throw away theory?

Uh, yeah. A theory that fails to describe reality accurately is false. I accept the fact that there are limits to the accuracy of measurements, that's not the problem.

The theory may have to be revised. We may not have understood the theory well enough in the first place. It may be completely bogus.

Uh, yeah. A theory that fails to describe reality accurately is false. I accept the fact that there are limits to the accuracy of measurements, that's not the problem.

The theory may have to be revised. We may not have understood the theory well enough in the first place. It may be completely bogus.

MetaKron, let's try it one more time. And the only reason I lost patience with you earlier is that you seemed to making no attempt to try and understand and primarily because you took a strong know-it-all-already attitude. You aren't in a position to know all there is to know and it's annoying (for me) to deal with anyone like that. But I'll tone it down and see if we can make some progress here.

First of all, no - the laws of thermodynamics are correct and don't need revising. We just haven't gotten the operating principle of the heat pump across to you yet.

In many ways a heat pump can be compared to a hot-water solar heater. You install a solar collector on your roof and it absorbs heat from the sun. A small pump then takes that heated water into your house. In that case, I believe that you should be able to see that the small amount of energy (in electrical form) required to run the little pump is considerably less than the amount of energy ( in the form of heat) that is delivered to you.And there is no violation of thermodynamics here either. I hope you can surely see that. The principle is exactly the same as leaving a car parked in the sun ans the interior becomes heated (gains energy) without you having to expend any energy at all. The only difference in the car and the system at home that I just described is that you DO use a small amount of power, but only to deliver that energy to where you want it to be.

Now let's compare that solar system to a heat pump. In both cases, solar energy is used to heat our collector. In the solar system, the collector is the panel on the roof; for a heat pump, the collector is simply the outside air. Both will receive energy from the sun and store it for a period of time.

In the solar roof collector, the heat energy becomes concentrated in the water because it is somewhat trapped - just as it in in the inside of a car sitting in the sun. For a heat pump system, the energy is still collected but it's more diffused in the air - in other words it's not concentrated in one specific volume of material but rather spread out more. I believe you will also agree that a given volume of air at 30 degrees C will contain more energy than the same volume of air at 20 degrees C. And that forms the basis for the operation of the heat pump system.

The heat pump will take a huge volume (hundreds of cubic feet) of that 30 degree air, absorb a lot of the heat energy by evaporation of the refrigerant, and then blow the air back out at 20 degrees. (The actual working temperatures are different but we'll stick with those figures from our example above.)

The heat pump is not some sort of perpetual motion machine and has not created energy from nothing - it collected that energy from the air - by cooling the air. An ordinary window-type air conditioner does exactly the same thing. It "sucks" the heat from the air in a room and blows it outside. If you've ever been near one you will know what I mean. The air it's blowing outside is very warm. A heat pump works on that same identical principle and the only difference is that it's blowing the heat INSIDE the house instead of the air conditioner blowing it to the outside. In fact, you could take that very same window unit and turn it around and have it heat the room in the winter. And that's precisely what a heat pump does - it reverses to provide cooling in the summer and heating in the winter.

The laws of thermodynamics have NOT been violated in the least. All the system has done is move heat from one location to another. It has also increased the intensity of the heat, just as you felt the air conditioner do on the outside of the house. But it did not somehow miraculously "manufacture" that heat from nothing which would violate thermodynamics. The heat is already there - it just gets moved.

Now - does that help?

Light, you're not quite to where my problem is. My problem is not with the idea of taking heat from a larger mass at lower temperature and using it to warm a smaller mass to a higher temperature. The books do balance there. My problem is that we can describe what it does, where the energy comes from, where the accounts balance, and we can even physically prove that it works, but it contradicts things that we are taught about the way heat works. We are pushing heat uphill at a net gain for the energy expended. It takes energy to chill an area. I can see the books balancing if the cold end heat contributed energy to the cycle in a way that aided in pushing itself uphill. This would seem as if we are converting ambient heat to usable heat at a net gain.

Light, you're not quite to where my problem is. My problem is not with the idea of taking heat from a larger mass at lower temperature and using it to warm a smaller mass to a higher temperature. The books do balance there. My problem is that we can describe what it does, where the energy comes from, where the accounts balance, and we can even physically prove that it works, but it contradicts things that we are taught about the way heat works. We are pushing heat uphill at a net gain for the energy expended. It takes energy to chill an area. I can see the books balancing if the cold end heat contributed energy to the cycle in a way that aided in pushing itself uphill. This would seem as if we are converting ambient heat to usable heat at a net gain.

OK, I think I see a little more of your problem. What you're failing to grasp is that there is NO net gain of energy - it's all already there. Just as with the solar collector, the "energy books" are balanced. And the solar collector in no way contributes energy to "pump the heat uphill" either. It simply moves the available heat. The heat pump does exactly the same. In both cases the source of the usable heat is the sun. Both of those systems simply concentrate it for delivery to where we want it to go.

In the heat pump, you are using a small amount of energy to drive the compressor which does the work of concentrating the heat that's already available. I feel you don't quite understand just how much heat is present in a large mass of air and how it can be removed - and taken elsewhere - just by dropping it's temperature a few degrees.

Question: I don't know what part of the world you live in so is it possible you've never seen the window air conditioner I was talking about? The operating principle is VERY clear if you can get to one.

MetaKron,

The problem you have is in how you're attempting to view the energy balance and apply an efficiency. A heat pump is not an easy device from which to derive a precise efficiency, that is why the CP is used.

The pump does the work of "pushing the heat uphill" as you put it. The available deliverable heat is the net of that, plus the heat gained from the low-temp reservoir, minus losses.

We are not converting ambient heat to usable heat at a net gain. Obviously we can't do that, that violates the 2nd law of thermodynamics... what we are doing is ADDING energy to the system via the pump.

So you have heat from low-temp reservoir (Q1) + Work of pump (W) = heat available for heating (Q2) + losses.

OK, I think I see a little more of your problem. What you're failing to grasp is that there is NO net gain of energy - it's all already there. Just as with the solar collector, the "energy books" are balanced. And the solar collector in no way contributes energy to "pump the heat uphill" either. It simply moves the available heat. The heat pump does exactly the same. In both cases the source of the usable heat is the sun. Both of those systems simply concentrate it for delivery to where we want it to go.

In the heat pump, you are using a small amount of energy to drive the compressor which does the work of concentrating the heat that's already available. I feel you don't quite understand just how much heat is present in a large mass of air and how it can be removed - and taken elsewhere - just by dropping it's temperature a few degrees.

Question: I don't know what part of the world you live in so is it possible you've never seen the window air conditioner I was talking about? The operating principle is VERY clear if you can get to one.

Flunch stated that we are adding energy to the system using the pump. That obviously can't be it because a pump is worse at adding energy to the system than is resistance heating. I understand very well how much heat is present in a mass of anything and how it can be removed and taken elsewhere just by, like you said. I am painfully familiar with window air conditioners. I have two of them that I use and one that I'm not sure what to do with.

It takes work to reduce the pressure of your working fluid, in this case most likely R-134. It takes work to compress it again. This is where you would supposedly lose too much energy to use this cycle to convert ambient energy to useful energy. You also have losses due to friction between the fluid and the plumbing. Those who don't understand that may understand it more easily when you think of all friction as being due to collisions between molecules.

Yes, I can understand, and I think I'm repeating myself, taking energy from a larger reservoir and concentrating it into a smaller reservoir. It's sort of like using a 200 foot water wheel on a river at a fraction of a PSI at the bottom to develop 100 PSI in a column of water 200 feet high. This analogy is not exact, and none of the analogies that I have seen so far addresses the problem that it takes work to move the caloric content to a higher and more useful level. Flunch agrees that this is impossible to do at a net gain. The Wiki article literally says that a COP of 4 means 400 percent efficiency and that a resistance heater is 100 percent efficient.

The analogy of the water wheel means that you are using the energy from the river to concentrate the energy you receive from the river. That's from a large reservoir at low intensity to a small reservoir at high intensity. If I were trying to support a hypothetical device that would produce useful energy from ambient energy, I would use just such an analogy. I would think that at least some of the jeering section would point out all the things that I have pointed out, and of course, like most crackpots, I wouldn't have a telescope for them to refuse to look through. Some people seem unable to see it when it is right in front of them.

And yes, this is a lossy process just like any other, but the loss definitely doesn't come out of the energy we supply to the pump motor. If it did, we wouldn't be seeing COPs of 3 or 4. They wouldn't reach 1. The losses have to come out of the energy that we are concentrating. No one has yet in this thread given a mechanism for concentrating that energy without expending more energy than we get out of it. There is an actual mechanism for doing this, and I guess I'll go ahead and mention it. I believe that the actual mechanism is in the vaporization and condensation of the working fluid. This gives us a mechanism for sorting out hot from cold molecules, a way to create a difference in energy levels that makes ambient heat usable. There is a temperature of evaporation difference in the energy levels between a liquid at its boiling point and the vapor after it has boiled, even when the liquid and the vapor are at the same temperature. For water this number is very high, 510 calories per gram, more than five times as much energy as it took to get it up to that temperature. The existence of these droplets makes it possible for the heat picked up from the cold end to pump the working fluid by increasing the pressure by vaporizing the droplets. At the hot end, condensation of those droplets makes it easier to compress the working fluid, even though the cycle has to start with using energy to compress it.

This I believe is the missing link that I was looking for.

Flunch stated that we are adding energy to the system using the pump. That obviously can't be it because a pump is worse at adding energy to the system than is resistance heating. I understand very well how much heat is present in a mass of anything and how it can be removed and taken elsewhere just by, like you said. I am painfully familiar with window air conditioners. I have two of them that I use and one that I'm not sure what to do with.

A big part of the problem is that you are looking at it from a typical high school level. At that stage of education they present you with a large number of loosely connected facts but don't do very much in the way of tying all those principles together into actual working systems . And that's why you keep talking about violating the laws of thermodynamics and "pushing heat uphill." Since you have those air conditioners you can actually FEEL one pumping heat outdoors. The other major problem is that you don't fully understand the refrigeration cycle - as we can see form several of your statements below. So that's where you should really be applying your efforts to try and learn.

One more thing here, Flunch is correct about adding energy to the system to operate the pump, you simply fail to understand what was meant. That added heat (power to drive the compressor and fans) is largely lost due to radiation and convection and little of it is delivered to heat the house. It's purpose and use is to collect and deliver the heat from it's source (outside air) to where you want it - inside the house. That energy contributes very little to the heat you are receiving.

It takes work to reduce the pressure of your working fluid, in this case most likely R-134. It takes work to compress it again. This is where you would supposedly lose too much energy to use this cycle to convert ambient energy to useful energy.

That's almost totally incorrect. It requires NO energy input (work) to reduce the pressure of the working fluid! That happens when the liquid enters the evaporator. And as the liquid is evaporated and changed to a gas is precisely where it is absorbing (collecting) the heat which will later be released by compressing the gas into a liquid again. That does require energy to drive the compressor and is exactly where more heat is released from the phase change (gas to liquid) than is required to force the phase change. That is the very heart of the refrigeration process!!!

Flunch agrees that this is impossible to do at a net gain. The Wiki article literally says that a COP of 4 means 400 percent efficiency and that a resistance heater is 100 percent efficient.

Once again Flunch is correct and you seem to have overlooked that I said the exact same thing. The article is correct about those numbers, But you just fail to understand the idea that the input power is ONLY being used to concentrate and move the heat. You cannot compare it to the way you would determine the efficiency of an engine - energy in the fuel compared to what's delivered to the wheels of a car. A refrigeration machine is NOT an engine And I believe that's where your greatest hang-up is. It's an entirely different kind of device. Repeating: it is only a device to collect, concentrate and move heat around - NOT an engine.

Some people seem unable to see it when it is right in front of them.Careful! You're actually talking about yourself here. :D

And yes, this is a lossy process just like any other, but the loss definitely doesn't come out of the energy we supply to the pump motor. If it did, we wouldn't be seeing COPs of 3 or 4. They wouldn't reach 1.
Incorrect again. The losses DO occur in the power we are supplying to run the compressor and fans. (You really do need to study refrigeration a lot more.)

The losses have to come out of the energy that we are concentrating. No one has yet in this thread given a mechanism for concentrating that energy without expending more energy than we get out of it. There is an actual mechanism for doing this, and I guess I'll go ahead and mention it. I believe that the actual mechanism is in the vaporization and condensation of the working fluid. This gives us a mechanism for sorting out hot from cold molecules, a way to create a difference in energy levels that makes ambient heat usable. There is a temperature of evaporation difference in the energy levels between a liquid at its boiling point and the vapor after it has boiled, even when the liquid and the vapor are at the same temperature. For water this number is very high, 510 calories per gram, more than five times as much energy as it took to get it up to that temperature. The existence of these droplets makes it possible for the heat picked up from the cold end to pump the working fluid by increasing the pressure by vaporizing the droplets. At the hot end, condensation of those droplets makes it easier to compress the working fluid, even though the cycle has to start with using energy to compress it.

This I believe is the missing link that I was looking for.

You are finally getting a little closer. I've been trying to tell you all along that the "secret" lies in the expansion and compression of the working fluid. But it has no relation to "sorting out the hot and cold molecules" as in the story about Maxwell's demon. It's just very simple evaporation and condensation. Very, very basic stuff, really. Evaporation absorbs heat, condensation releases it. Again, that's the very heart of ANY refrigeration device - air conditioner, heat pump, household refrigerator, freezer, ice maker, etc. And once you really understand how those devices work, you'll be well on the way to seeing how a heat pump works.

You've actually made a little progress because you began by asserting it was MY claim that the things actually worked. So you've gained a little knowledge.

MetaKron, what you are talking about is called the "latent heat of vapourization" - the energy difference between the liquid and gas states of a fluid at the same temperature. You don't quite seem to have it yet but Light is right, you do seem to be making a little headway in your understanding of this cycle.

Flunch stated that we are adding energy to the system using the pump. That obviously can't be it because a pump is worse at adding energy to the system than is resistance heating.

This statement shows your lack of understanding, though I admit I was being a little loose with my turbomachinery nomenclature. The compressor increases the pressure of the fluid in a typical heat pump - a direct input of energy to the fluid. This energy is added to the energy that was gained from the cold temperature reservoir (which is carried by the fluid in the form of the latent heat of vapourization and any increase in temperature realised).

Some of this total energy is released to the hot temperature reservoir (i.e. your house) when the fluid goes through the condensation process. The fluid goes through a further decrease in energy when it expands through a valve and returns back to the cold temperature reservoir. By this time the temperature is low enough for it to start absorbing heat again from the environment and the cycle continues.

I'm not sure you have a firm grasp on that so I thought it warranted a quick run-through.

OK, first, my English may not be clear enough even though I am at least third or fourth generation American and most of my ancestors were English speakers. Mostly I think we're talking past each other. I have never claimed to believe that the heat pump claim was to remove more heat from the cold-side reservoir than was there, even if it may have sounded like that. I just don't believe that strict interpretation of the 2nd law allows for what heat pumps do. So what if I don't get that completely, I'm not sure that anyone does. Even in the simplest of propositions, complications can exist. About all you and Light have told me is where the heat comes from, which I already know in great detail. What I don't think either of you understand is how that heat is pumped uphill at a net gain in usable heat over the amount of energy you supply to the pump.

I am quite aware of how refrigeration works. A fluid with just the right latent heat of vaporization makes refrigeration a lot more efficient in any given space because you can use that to sink and source more heat faster. Compress the fluid and it gets hot. Push that fluid through whatever heat exchanger is best, like the hot side of your air conditioner. It cools during that phase. It cools even more when it is allowed to expand, and the chilled fluid is then pumped through the cold side. There it gains heat. That hot stuff has to be compressed again to be able to reject heat when it goes through the hot side exchanger again. This scheme also will not work unless there is some kind of constriction where the fluid circulates from the hot side to the cold side else the compressor will not be able to maintain pressure against the hot side. In the simplest setup one compressor motor will both create the pressure against the hot side and the vacuum against the cold side. Yes, I realize that this goal can also be accomplished by using a narrower guage of tubing on the hot side. Also, I am talking about a very basic model for mechanical refrigeration.

I would bet that the heat pump scheme cannot work at all with a working fluid that does not exist as a liquid part of the time and a vapor part of the time. One funny thing is that when you compress a liquid like Freon (do I have to say R-134 to be politically correct?) some of it becomes droplets because you've raised its boiling point. The rest becomes hotter both because the droplets have released their energy and the fluid is compressed. On the other end, when the Freon expands, it becomes colder. Droplets form because the freon got colder, which is a mixed advantage and disadvantage because this reduces the pressure, making the gaseous portion even colder, but the droplets release heat, which makes things warmer again. We've lowered the boiling point of the Freon, so the temperature can drop further before droplets form.

I think that the latent heat of vaporization, crossing and re-crossing that threshold, causes an excursion that turns uphill into downhill. When the Freon condenses on the hot side, it removes some of itself from the vapor, which reduces the workload on the compressor while raising the temperature or at least increasing the amount of heat that can be removed from the system. The fluid portion also conducts heat out of the mix a lot faster when it is in contact with the walls of the tubing. The better the unit can handle the fluid that condenses, the better your unit is going to work. This is not as easy as it sounds. Mixed fluid and vapor going through a jet into the expansion phase can cause the flow to stutter. This can be bad for the compressor and the tubing and compromise efficiency.

As opposed to a window air conditioning unit that is expected to be more or less a quick and dirty design, a heat pump to work at all is going to have to take maximum advantage of this. Even not knowing the details, this means more parts, more weight, more controls, more know-how. So they are expensive and a useful one probably won't fit in your window. It certainly won't weigh just under 40 pounds unless much more expensive materials and parts are used. One thing that you learn by any real exposure to manufacturing processes is that it is fairly difficult to put "just one more small part" into a system. Also, things that are relatively simple for a bright tinkerer to do, like run the cold side through a reservoir of water heated by solar or other, are difficult to impossible for a manufacturer because they add a lot of complications and don't sell. Integrated off-the-shelf units are the craze, and even a manufacturer with a multi-million dollar budget works hard to scrimp on maintenance, so anything that needs much attention is out, even if paying two technicians full-time wages would save a million dollars on energy costs. It's also hard to find people who can maintain a plant like that.

If I sound like I don't understand things, a lot of it is because I can't download everything I know into a few short messages. Also, understanding the refrigeration cycle does not mean understanding how to get 400 watts of heat out of a device for a 100 watt input even if there is a massive source of heat at a low temperature to draw from. The latent heat of vaporization thing didn't occur to me until later in the conversation. It isn't in the Wiki article.

Even a condensor in the line adds to the cost and weight of the mechanism. I can see where effective cooling could be had without one. Ideally the Freon that passes through the hot side would condense to a liquid and be introduced to the cold side as a liquid and allowed to expand. You need the pressure to be lower than the hot side, and the expansion tends to raise the pressure, just as the condensation on the hot side tends to lower the pressure, which helps the compressor do its work, but also tends to eliminate the difference in pressure between the hot side and the cold side. That's a balancing act. A condensor makes it more efficient because it it a lot easier to push liquids than gases and the liquid carries a lot more energy per mass or volume, or a larger deficit in energy as seems to be the case here.

I don't seem to remember a lot of what I read about refrigeration, and it's fun to go back and try to figure it out on my own because I can generate ideas that often aren't included in the reading material. It helps me realize things like the idea that a condensor can be a variety of things and I have to figure out what it does to know the concept. The condensor in a refrigeration unit is also where the freon is kept when it is turned off. It takes time for as much of the liquid as will condense runs back into it.

This reminds me of these "made simple" books from a few decades ago. Do they have a new series by now? It was sort of like a "for idiots" series, but after you read them, you knew all of the details that fit the print. They broke down systems in component parts and explained how each worked in detail. The reader would then know how a three-phase motor, a rocket, a refrigeration unit, or whatever the device was worked, and they included technical and mathematical details.

Once again, you are making progress - and that's good. :)

The difficulties you're having is not from a lack of information but result from not yet fully intergrating the information you already have. You are still laboring under a few (but important) misconceptions.

One minor thing I noticed in passing is that you aren't aware of window-sized heat pumps. I don't know where you live but they are VERY common in parts of the country in apartments and condos. The reason is that they provide both heating and cooling from the same unit and avois the complexities of providing furnaces in individual living quarters. It also saves the time and effort of installing electric resistance heaters along baseboards, though that is still quite popular too.

But since air conditioning is required anyway, you simply buy ONE unit, stick it in a window, plug it in and you immediately have both heating and coolilng. "Extra parts???" The only difference between just an air conditioner and a heat pump is a 4-way valve and a couple of short lengths of copper tubing.

Sure, heat of vaporization is the key to any refrigeration system!! The reason you didn't see it mentioned anywhere is because it is so elemental that all the writers assume that everyone already knows that. (It's about as basic a principle as you can find.)

The following two statements of yours clearly show that you still do not completely understand the refrigeration process even though you make every attempt to claim that you do:

"I would bet that the heat pump scheme cannot work at all with a working fluid that does not exist as a liquid part of the time and a vapor part of the time."

And, "On the other end, when the Freon expands, it becomes colder. Droplets form because the freon got colder, which is a mixed advantage and disadvantage because this reduces the pressure, making the gaseous portion even colder, but the droplets release heat, which makes things warmer again."

Of course it won't work without being a liquid at times and a vapor at other times. That IS what allows it to use the heat of vaporization. Unless there is that phase change, the device is useless.

Yes, as the freon expands it get colder (another basic principle) but NO droplets form in the evaporator where this expansion is taking place. It enters the evaporator already in a liquid state through an expansion valve or capillary tube (which is simply a very small diameter piece of tubing) and there it does nothing but evaporate - turns into a gas. There is NO condensation taking place which releases heat - none.

The only place condensation takes place is in the condenser (thus it's name) and that's all the way over on the other side of the process.

Seriously, once you get past these few little things you'll have a reasonably good understanding of the subject. :)

Well, actually, I believe that a heat pump or refrigeration unit would work without the phase change, but the heat pump would show no gain over the efficiency of a heating coil. If it is all you have for some reason, it is possible to build a refrigerator that uses just a compressible gas. I think there are applications that make this a requirement, and of course there are the Hilsch vortex type cooling units.

If I insist that the heat pump violates or appears to violate the 2nd law, and that it sounds like a crackpot claim, this is not the same thing as insisting that results of actual tests do not show that it works. I can insist that theory shows that it can't work, but I give in to exhaustive, repeated, independent testing.

I was only vaguely aware of window units that could work as heat pumps also. I don't think that Walmart carries them but I know of a store that might. They have to be more expensive and more complex, if for no other reason than to pay for the development program. I guess it would also have to be a Fedder's and not a Goldpak. You can do things with a refrigeration unit that you can't get away with using a heat pump, like letting mixed vapor and liquid move through a poorly designed condensor. Since its function is gravity dependent and sensitive to vibration, it would be almost mandatory that a car's AC unit be able to tolerate that. It reduces efficiency, but it would still work.

The Wiki explanation is very sketchy and the heat of vaporization is a very basic and essential part of a good explanation.

If I insist that the heat pump violates or appears to violate the 2nd law, and that it sounds like a crackpot claim, this is not the same thing as insisting that results of actual tests do not show that it works. I can insist that theory shows that it can't work, but I give in to exhaustive, repeated, independent testing.

Yeah, I can see that's your biggest hang-up. But it's only because you still don't completely understand it. There can never be a violation of the 2nd law.

The only problem is that you are thinking of it as a closed system with only a single source of energy - the electrical power. If that were true, it really would be a violation. But for some reason - known only to you - you cannot seem to understand that it uses that energy ONLY for the purpose of gathering additional energy.

And I thought you were getting so close...

There are almost as many ways to rephrase that as there are writers. I never claimed that the heat pump even appeared to violate the first law, which is the conservation law. It is a subset of the law of conservation of matter and energy which states that matter and energy cannot be created or destroyed, only converted from one form to another.

Here are some versions:

Energy spontaneously tends to flow only from being concentrated in one place
to becoming diffused or dispersed and spread out. (http://www.secondlaw.com/two.html)

I don't think much of this Wiki article but here is a quote. This is pretty much how I have understood the second law:

A system operating in a cycle cannot produce a positive heat flow from a colder body to a hotter body (Clausius) (http://en.wikipedia.org/wiki/Second_law_of_thermodynamics)

These two statements imply to me that according to this law it takes more than 100 watts of energy to pump 100 watts of heat uphill. I'm cool with getting the rest of the watts that it takes out of the cold side reservoir.

There are almost as many ways to rephrase that as there are writers. I never claimed that the heat pump even appeared to violate the first law, which is the conservation law. It is a subset of the law of conservation of matter and energy which states that matter and energy cannot be created or destroyed, only converted from one form to another.

Please pay attention. I never once mentioned the first law.

Here are some versions:

Energy spontaneously tends to flow only from being concentrated in one place
to becoming diffused or dispersed and spread out. (http://www.secondlaw.com/two.html)

I don't think much of this Wiki article but here is a quote. This is pretty much how I have understood the second law:

A system operating in a cycle cannot produce a positive heat flow from a colder body to a hotter body (Clausius) (http://en.wikipedia.org/wiki/Second_law_of_thermodynamics)

These two statements imply to me that according to this law it takes more than 100 watts of energy to pump 100 watts of heat uphill. I'm cool with getting the rest of the watts that it takes out of the cold side reservoir.

Look closely at both of those - especially the first which makes it even more clear where it says "spontaneously." What you are failing to recognize is that neither of those statements preclude the ability to apply external power to the system (as with the refrigeration compressor) to reverse the heat flow. Both statements are talking about static conditions - like placing an ice cube in the sun. You cannot do that, they both say, and make the ice cube get colder.

You will eventually understand all this when you get older. I guess you'll just have to wait until then - when you'll also learn why turbines are more efficient, too.

Knock off the cracks about my apparent mental age. What you are not understanding is that I have never objected to the idea that the hot side gets hotter and the cold side gets colder. What I said, over and over again, is that I have been told that the second law says that you cannot do this without expending more energy than you move from the cold side to the hot side. Supposedly, according to several authorities that I have read, it should take more than 100 watts of energy supplied to the electric motor powering the compresser to move 100 watts of heat from hot side to cold side.

Knock off the cracks about my apparent mental age. What you are not understanding is that I have never objected to the idea that the hot side gets hotter and the cold side gets colder. What I said, over and over again, is that I have been told that the second law says that you cannot do this without expending more energy than you move from the cold side to the hot side. Supposedly, according to several authorities that I have read, it should take more than 100 watts of energy supplied to the electric motor powering the compresser to move 100 watts of heat from hot side to cold side.

That wasn't intended to be a crack about your mental age, just a statement about your actual age. (Which you seem to still be afraid to reveal, by the way.)

And everything that you "supposed" from all those authorities is still incorrect.

Knock off the cracks about my apparent mental age. What you are not understanding is that I have never objected to the idea that the hot side gets hotter and the cold side gets colder. What I said, over and over again, is that I have been told that the second law says that you cannot do this without expending more energy than you move from the cold side to the hot side. Supposedly, according to several authorities that I have read, it should take more than 100 watts of energy supplied to the electric motor powering the compresser to move 100 watts of heat from hot side to cold side.

Hmmm... And after having just responded, I noticed your final statement more clearly. Are you now talking about standard air conditioners and refrigerators as opposed to heat pumps? It would appear so.

I have been told this stuff by people who I have more than a little reason to believe. It is a doctrine that I have found in several books. The doctrine is that the second law prohibits 100 watts of heat from moving uphill unless you spend more than 100 watts pumping it. So doctrine is wrong. I'm just telling you that I was told this thing about the second law. I have also told you more than once that I accept verifiable experimental evidence over theory or doctrine. And actually, until we started this discussion, I assumed that you would be one person who would tell me that you can't get 400 watts of heat for 100 watts of electrical power out of a heat pump or that it didn't mean what I thought it meant. Now I find out that it means exactly what I think it means. Doctrine is wrong and in realworld examples, 1000 watts of electricity moves about 4000 watts of heat uphill a certain number of degrees. This is probably why I used both window units for about half the day each and only spent 40 dollars on electricity. The one in the kitchen is newer and runs during the hot part of the day. The one in the bedroom is only on when I'm home and runs during the cool part of the day, which means it probably draws extremely low power most of the night. (During the summer)

What I have been trying to get at is how the gain occurs. I don't think that using a pure gas with no liquid phase is going to let you pump heat out of an area without spending more energy than you extract. I think that the condensation at the hot side does the job, for reasons I have already explained, and that's how you get gain.

There isn't anything in the Wiki article that explains that there is any difference between a heat pump and a "standard" refrigerator or AC. It would seem like a better heat pump design would make a better air conditioner or refrigerator. The big differences include the fact that if the heat pump and the AC are the same unit, that unit has to be reversible without physically moving parts. That takes some doing to design to work right. The other is that the heat pump can't get away with inefficient design or it will rapidly fail to work as a heat pump. People expect their air conditioners to suck power, but the whole idea of the heat pump is to save electricity, so it actually has to do it.

And another thing about a unit that is expected to conserve power is that if you use a heavier unit, larger compressor, larger reservoir of freon, more fancy tricks, you can get a little more efficiency than you can out of a unit that is compact and has to be less than a certain weight.

I have been told this stuff by people who I have more than a little reason to believe. It is a doctrine that I have found in several books. The doctrine is that the second law prohibits 100 watts of heat from moving uphill unless you spend more than 100 watts pumping it. So doctrine is wrong. I'm just telling you that I was told this thing about the second law. I have also told you more than once that I accept verifiable experimental evidence over theory or doctrine. And actually, until we started this discussion, I assumed that you would be one person who would tell me that you can't get 400 watts of heat for 100 watts of electrical power out of a heat pump or that it didn't mean what I thought it meant. Now I find out that it means exactly what I think it means. Doctrine is wrong and in realworld examples, 1000 watts of electricity moves about 4000 watts of heat uphill a certain number of degrees. This is probably why I used both window units for about half the day each and only spent 40 dollars on electricity. The one in the kitchen is newer and runs during the hot part of the day. The one in the bedroom is only on when I'm home and runs during the cool part of the day, which means it probably draws extremely low power most of the night. (During the summer)

What I have been trying to get at is how the gain occurs. I don't think that using a pure gas with no liquid phase is going to let you pump heat out of an area without spending more energy than you extract. I think that the condensation at the hot side does the job, for reasons I have already explained, and that's how you get gain.

There isn't anything in the Wiki article that explains that there is any difference between a heat pump and a "standard" refrigerator or AC. It would seem like a better heat pump design would make a better air conditioner or refrigerator. The big differences include the fact that if the heat pump and the AC are the same unit, that unit has to be reversible without physically moving parts. That takes some doing to design to work right. The other is that the heat pump can't get away with inefficient design or it will rapidly fail to work as a heat pump. People expect their air conditioners to suck power, but the whole idea of the heat pump is to save electricity, so it actually has to do it.

And another thing about a unit that is expected to conserve power is that if you use a heavier unit, larger compressor, larger reservoir of freon, more fancy tricks, you can get a little more efficiency than you can out of a unit that is compact and has to be less than a certain weight.

Well, you've still gotten better but still not quite there yet. The law is NOT wrong at all. What's wrong is the way you are trying to use it. I've already tried to tell you that the law is talking about ONLY the natural tendencies of things WITHOUT the external application of energy.

Let me try and put it in simple terms that you might understand. The laws of thermodynamics can be compared to the law of gravity. Gravity clearly says that water flows downhill - always. Period. It says absolutely nothing about you taking a bucket and carrying the water back uphill. Nor does it say anything at all that forbids you using a pump to send it back up. So is it with thermodynamics. It considers NO pump, no buckets, no nothing - just natural heat flow. I cannot see why you fail to understand something so simple.

And there most certainly IS a difference between a refrigerator and a heat pump. And I've already told you. It's called a 4-way valve, remember? It reverses the flow of the working fluid. The condenser becomes the evaporator and the evaporator becomes the condenser. It only depends on which way you want the heat to go - to the inside or the outside. It would be rather foolish to build that into a household refrigerator since there is never any need to heat it inside.

I cannot see why you fail to understand something so simple.


I have not failed to understand that. I know the difference between using a pump to pump heat to a higher temperature and the natural tendencies of heat. I have made it very clear that other people say that it can't be done at a net gain in usable heat, and that I am the one who believes it when I see it. I have also explained more than once that the first thought is that it can be done but it takes more energy to pump it than you get out of it.

And there most certainly IS a difference between a refrigerator and a heat pump. And I've already told you. It's called a 4-way valve, remember? It reverses the flow of the working fluid. The condenser becomes the evaporator and the evaporator becomes the condenser. It only depends on which way you want the heat to go - to the inside or the outside. It would be rather foolish to build that into a household refrigerator since there is never any need to heat it inside.

No, a refrigerator is a heat pump and so is an air conditioner. It is just that those are not readily reversible to move heat the other direction and they don't need to be. The problem with trying to reverse the action of a heat pump is that for optimal efficiency the hot side and cold side are physically different. Larger gauge tubing on the cold side lets the liquid expand better. Smaller gauge tubing on the hot side gives better compression. I would have to look for specific designs to see how they handle that because it looks to me like if you make it reversible from the control panel one side or both will be inefficient.

I have not failed to understand that. I know the difference between using a pump to pump heat to a higher temperature and the natural tendencies of heat. I have made it very clear that other people say that it can't be done at a net gain in usable heat, and that I am the one who believes it when I see it. I have also explained more than once that the first thought is that it can be done but it takes more energy to pump it than you get out of it.

You misunderstand me. Those "other" people (assuming they are smart enough) should also know that it's possible. I believe you are misunderstanding them - just as you did me.



No, a refrigerator is a heat pump and so is an air conditioner. It is just that those are not readily reversible to move heat the other direction and they don't need to be. The problem with trying to reverse the action of a heat pump is that for optimal efficiency the hot side and cold side are physically different. Larger gauge tubing on the cold side lets the liquid expand better. Smaller gauge tubing on the hot side gives better compression. I would have to look for specific designs to see how they handle that because it looks to me like if you make it reversible from the control panel one side or both will be inefficient.

In the strictest sense, yes, a refrigerator does pump heat. However is does NOT qualify for the term "heat pump" because that name refers to a specific type of reversible unit. So your statement is incorrect.

Yes, you are right about the efficiency angle. But that's what engineering is all about. Certain compromises have to be made but they can be done in such a way that the efficiency doesn't really suffer an appreciable amount. It's still better than having to supply one unit just for heating and another just for cooling in many cases. Especially in the apartment example I gave and were you get rate breaks for having an all-electric home. It also depends on your climate as well.

Actually, I think that it's convention to call it a heat pump when it can heat the inside of the house whether it is reversible or not.

It may be better to supply one unit for heating and one or several units for air conditioning when you are getting COPs of 3 or 4 and that would be reduced. The cheap window units seem to be very efficient. This of course is something I need to actually calculate out. The window unit in the kitchen would use a lot less power if I could keep it out of the sun, but it doesn't use much as it is. The setup using a reversible heat pump seems really vulnerable to getting a COP of 3 or 4 in one mode and less than 1 in the other. Or you have to split the difference between both sides, which increases the expense of using either side. Unless I can find some numbers showing me equal efficiency either way, I would rather use a dedicated heat pump for heat and window units for AC because the window units that I am using seem to do a really good job without spending a lot of money.

This really is a serious issue, too, when you realize that design compromises might double a utility bill from $150 a month to 300 a month or worse.

Actually, I think that it's convention to call it a heat pump when it can heat the inside of the house whether it is reversible or not.


No, absolutely not true at all. That's just what you think it is and you are incorrect. Refrigerators, air conditioners, freezers and the like were in use for many, many years before the device and the term "heat pump" ever came into use.

While it's certainly true that those devices do pump heat, trying to apply the term as you are doing is still not correct. For example, you could call an airplane a "car" because it's perfectly capable of driving along the surface of a road. But that doesn't make it a car. It's capable of doing more (flying) and so is the device we call a heat pump (it's reversible).

This really is a serious issue, too, when you realize that design compromises might double a utility bill from $150 a month to 300 a month or worse.

Once again, as you so often do, you are simply talking without the benefit of actually knowing any facts. The actual compromises are very small - nothing like you are assuming !

You are good at thinking, but unfortunately your thinking isn't very good. :D You still need to learn the importance of getting facts before speaking.

How about, forewarned is forearmed? Technology has both real and potential faults that are predictable when you think them through. I would want to see the ratings that show me that I am better off buying a piece of machinery that is a compromise design, or a compromise of a compromise, and that includes figuring out the initial cost of the plant.

How about, forewarned is forearmed? Technology has both real and potential faults that are predictable when you think them through. I would want to see the ratings that show me that I am better off buying a piece of machinery that is a compromise design, or a compromise of a compromise, and that includes figuring out the initial cost of the plant.

Well, guess what? Those ratings are posted right on the machines! It's required by law. (See? There's two more important things that you didn't know.)

Well, guess what? Those ratings are posted right on the machines! It's required by law. (See? There's two more important things that you didn't know.)

What makes you think I didn't know that? You assume too much.

What makes you think I didn't know that? You assume too much.

Well, silly one, it's precisely because you said: "I would want to see the ratings that show me that I am better off buying a piece of machinery that is a compromise design, or a compromise of a compromise, and that includes figuring out the initial cost of the plant."

So I simply pointed out that what you "want to see" is right there waiting for you to look at it!!!!!!!!!!!

And you don't have to "figure out the cost", it's also posted right on the unit. And if you mean before "compromising", there is no such silly data available. They are designed exactly as they are designed - not modified.

So just how is that "assuming?"

(Yeah, I know. You learn something and then come back acting like you knew it already. You've done that several times before - and it isn't very smart of you.)

Heat pumps work. Except one time in a Holiday Inn in South Bend, Indiana in mid January when the temp was 10 F. No go.

I should be able to take one of my window unit AC and turn it around and heat my inside of my house. Efficiency? Well, maybe not tops. But, it should work.

Perhaps a ( very ) crude but effective science experiment for anyone doubtful about life, the universe, and heat pumps.

Heat pumps work. Except one time in a Holiday Inn in South Bend, Indiana in mid January when the temp was 10 F. No go.

I should be able to take one of my window unit AC and turn it around and heat my inside of my house. Efficiency? Well, maybe not tops. But, it should work.

Perhaps a ( very ) crude but effective science experiment for anyone doubtful about life, the universe, and heat pumps.

Yes, it would work fairly well until/unless you encounterd the low temperatures you mentioned. Just don't forget to drain the condensate outside and also keep it away from the condenser coil where it's normally used to remove some of the heat. :D

Well, silly one, it's precisely because you said: "I would want to see the ratings that show me that I am better off buying a piece of machinery that is a compromise design, or a compromise of a compromise, and that includes figuring out the initial cost of the plant."

So I simply pointed out that what you "want to see" is right there waiting for you to look at it!!!!!!!!!!!

And you don't have to "figure out the cost", it's also posted right on the unit. And if you mean before "compromising", there is no such silly data available. They are designed exactly as they are designed - not modified.

So just how is that "assuming?"

(Yeah, I know. You learn something and then come back acting like you knew it already. You've done that several times before - and it isn't very smart of you.)

You teach class that way, don't you? No wonder we're all going to have to learn Chinese in a couple of decades.

At least reading this thread is entertaining...

Well, I'm always guilty of responding to it, but I'm not the one who started flame-baiting.

From an impartial 3rd party standpoint your refusal to believe well established laws of thermodynamics is kind of maddening but Light could definitely tone down the rhetoric and personal attacks. If, in fact he is (was) a teacher I hope he didn't teach by ridiculing people.

From an impartial 3rd party standpoint your refusal to believe well established laws of thermodynamics is kind of maddening but Light could definitely tone down the rhetoric and personal attacks. If, in fact he is (was) a teacher I hope he didn't teach by ridiculing people.

I retired from teaching, Flunch. And no, I didn't ridicule anyone. However, this particular kid is NOT one of my students and deserves no slack. Why? Because he continuously claims to know all the answers. I've led him through this whole process and he HAS learned from it. But every single time he picks up a new fact he then proceeds to try and make it appear that he knew it all along. That is not the way a true student behaves. And that's why I say he's no student of mine - I'd chase him from the classroom in a heartbeat! Again, why? Because he's smug, denies what he said earlier (many times!), and acts far too superior. In essence, he's just a jerk.

As to my personal style, check out some other threads - like the one on hurricanes - and see how I deal with ordinary reasonable people like Valich. You will find that I did ridicule URI and that's simply because he is another nut case - but not as bad as Buddah1 and Duendy. :D I'm also very patient with people like The Empty Force of Chi and several others who are actually trying to learn.

But back to this particular individual for a moment. He hasn't even the good sense to ask questions - he simply makes statements. Over and over again that have to be constantly cleared up. And yes, it's rather maddening when you have to teach by something that approaches brute force.

Incidentally, I never once treated any of my students like that during eleven years of teaching - but I did force a few out of the class because they acted just like this jerk we're discussing.

Yeah, I'll bet you were a real prince.

Yeah, I'll bet you were a real prince.

It would seem close to being true. All of my students that made it through the whole session expressed appreciation for having been in my class. I just eliminated all the jerks first - it made it better for the other students.

And no, you probably wouldn't have made it past the first day.

Whatever.

i read the first post and the last page and it seems you have gotten off the track.
why not bioengineer a giant butt muscle to power our cars? or a giant electric eel to power electric cars?
or a giant squid to power our submarines? (silent drive?)
think outside the box.

i read the first post and the last page and it seems you have gotten off the track.
why not bioengineer a giant butt muscle to power our cars? or a giant electric eel to power electric cars?
or a giant squid to power our submarines? (silent drive?)
think outside the box.

If I had any of those I'd certainly want to keep them INside the box! :D

i read somewhere that the most efficient internal combustion engine can achieve is 50% the other half(or more) is expended as heat, so the only way to increase an engines efficiency is to utilize the waste heat somehow.

The thread starter described a BOMB CALORIMETER. Now, the trick would be, how to turn the heat into work before it escapes as waste heat.

We are already half way there! It's so easy when we break the problem down into parts!

OK, I did MY half. Now its your turn(s).