# When the a/c has been off…

#### wegs

##### Matter and Pixie Dust
Valued Senior Member
…in less than one hour, the house heats up by 3 to 4 degrees. (That’s a lot in the dead of summer.) So, a/c digital monitor reads 76 degrees Fahrenheit, shut the system off, and it’ll be 80 degrees in less than one hour. When it’s turned on again, it takes three hours to get back to 76 degrees.

Wtf?? (I’m upset because I have a brand new a/c unit but it keeps shutting off due to a condensation pan issue.) *eye roll*

I want to say that exchemist explained this to me before but I can’t find the thread, now. “Online a/c experts” try to explain it, but it’s still mind boggling to me that it takes less than ONE hour to feel like I’m baking in an oven and three hours or more to feel comfortable!

Okay, an oven is an exaggeration, but you get the idea.

I want to know why it takes longer to cool down a house than heat it up. No math equations, please.

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…in less than one hour, the house heats up by 3 to 4 degrees. (That’s a lot in the dead of summer.) So, a/c digital monitor reads 76 degrees Fahrenheit, shut the system off, and it’ll be 80 degrees in less than one hour. When it’s turned on again, it takes three hours to get back to 76 degrees.

Wtf?? (I’m upset because I have a brand new a/c unit but it keeps shutting off due to a condensation pan issue.) *eye roll*

I want to say that exchemist explained this to me before but I can’t find the thread, now. “Online a/c experts” try to explain it, but it’s still mind boggling to me that it takes less than ONE hour to feel like I’m baking in an oven and three hours or more to feel comfortable!

Okay, an oven is an exaggeration, but you get the idea.

I want to know why it takes longer to cool down a house than heat it up. No math equations, please.

It's a grudge match. "In this corner we have the undefeated champion of the Solar System, the Sun! In the other corner, we have the challenger, a puny little air conditioner...Let's get it on!"

Actually, I don't live in Florida and all I have is a portable a/c, that I use for one room, my "office". When it warms up to the point where I'm feeling a little uncomfortable, I turn the a/c on and it's cool within a few minutes.

In your case, it's very hot outside and you are trying to cool the entire house. You are probably trying to keep the house 30 degrees cooler than the outside temp. That's a battle. When the a/c goes off, it's not going to take long to lose that battle. When you turn the a/c back on, it's going to take a while to cool the whole house down by enough to feel comfortable in such an extreme environment.

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It's a grudge match. "In this corner we have the undefeated champion of the Solar System, the Sun! In the other corner, we have the challenger, a puny little air conditioner...Let's get it on!"

Actually, I don't live in Florida and all I have is a portable a/c, that I use for one room, my "office". When it warms up to the point where I'm feeling a little uncomfortable, I turn the a/c on and it's cool within a few minutes.

In your case, it's very hot outside and you are trying to cool the entire house. You are probably trying to keep the house 30 degrees cooler than the outside temp. That's a battle. When the a/c goes off, it's not going to take long to lose that battle. When you turn the a/c back on, it's going to take a while to cool the whole house down by enough to feel comfortable in such an extreme environment.
Thank you! That makes sense, I hadn’t considered the 95 degree near constant temps outside, so the house is dealing with an “extreme environment.”

One degree drop per hour just seems way too slow, but maybe, I’m expecting too much. lol

Thank you! That makes sense, I hadn’t considered the 95 degree near constant temps outside, so the house is dealing with an “extreme environment.”

One degree drop per hour just seems way too slow, but maybe, I’m expecting too much. lol
It also depends on the size of our a/c in terms of the sq ft of your house. If you had a unit meant for a large retain store and you used in in the house, it would cool off a lot faster.

My portable a/c, when used just for one room, cools it like a refrigerator within a few minutes. If I tried to use it for my whole house, it couldn't do it.

Now we're going to find out that you have a 10,000 sq ft house...

It also depends on the size of our a/c in terms of the sq ft of your house. If you had a unit meant for a large retain store and you used in in the house, it would cool off a lot faster.

My portable a/c, when used just for one room, cools it like a refrigerator within a few minutes. If I tried to use it for my whole house, it couldn't do it.

Now we're going to find out that you have a 10,000 sq ft house...
lol It’s roughly 2200 square feet and the unit that has the condensation pan is in my garage.

lol It’s roughly 2200 square feet and the unit that has the condensation pan is in my garage.
Is the issue that the pan just fills up too quickly and does that shut off the a/c? I know it's humid there but I figured the pan would just overflow rather than shut off.

[...] (I’m upset because I have a brand new a/c unit but it keeps shutting off due to a condensation pan issue.) *eye roll* [...]

Does the drain line from the pan get clogged easily? [Or -- does it even have one?] We've got a unit that has a dry or dehumidifer mode that will remove a lot more moisture from the air than an AC normally does, if that option is turned on. Though I can also see how in a state known for high humidity, it might be cranking out a lot more droplets than it would elsewhere, regardless.
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Does the drain line from the pan get clogged easily? [Or -- does it even have one?] We've got a unit that has a dry or dehumidifer mode that will remove a lot more moisture from the air than an AC normally does, if that option is turned on. Though I can also see how in a state known for high humidity, it might be cranking out a lot more droplets than it would elsewhere, regardless.
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Yes, the pan is overflowing and there is a “floating” valve that once it’s triggered (due to the overflow of pan water), it shuts the system off. An a/c tech usually runs a water line/hose through the pipe to push the clogged area out; sometimes a “gelatinous” blob flows out through the exterior pipe outdoors, which is apparently a build up, common during this time of year. This is one of the reasons I’m kind of over the Southeast; the summers are smothering hot.

Is the issue that the pan just fills up too quickly and does that shut off the a/c? I know it's humid there but I figured the pan would just overflow rather than shut off.
Yep, see my response above.

Yes, the pan is overflowing and there is a “floating” valve that once it’s triggered (due to the overflow of pan water), it shuts the system off. An a/c tech usually runs a water line/hose through the pipe to push the clogged area out; sometimes a “gelatinous” blob flows out through the exterior pipe outdoors, which is apparently a build up, common during this time of year. This is one of the reasons I’m kind of over the Southeast; the summers are smothering hot.
I remember, as a kid in eastern NC, that winter was gloomy since there was no greenery. The trees were all deciduous and then when Easter arrived, it was sunny and warm but then the humidity kicked it and it still wasn't pleasant being outside.

I remember, as a kid in eastern NC, that winter was gloomy since there was no greenery. The trees were all deciduous and then when Easter arrived, it was sunny and warm but then the humidity kicked it and it still wasn't pleasant being outside.
I have some friends in NC and at least, they have a more distinct change of seasons. October to March here is pretty moderate though, with starry night skies. I miss having a “proper” winter.

I have some friends in NC and at least, they have a more distinct change of seasons. October to March here is pretty moderate though, with starry night skies. I miss having a “proper” winter.
Yeah, 4 seasons is the best really. Spokane was nice in that regard. Here we have summer (which is very nice) and fall and then drizzle with clouds for half the year. We do generally get a week of snow but I live on a steep hill so even that can be a pain. Spokane was perfect in that regard as was Boone, NC.

I want to know why it takes longer to cool down a house than heat it up. No math equations, please.
Let's use some numbers (no math I promise) -

Let's say your house is average sized. That means it's receiving about 170 kilowatts of sunlight at noon. Most of that is converted to heat. Hopefully most of that stays outside due to your insulation - but some is going to make it inside.

A 12,000 BTU air conditioner can remove about 3.5 kilowatts of heat.

That's the battle that's being fought - and your air conditioner is hopelessly outclassed. It can't cool the entire house, not even close. At best it can cool the space you are in - the space INSIDE all the insulation and doors and wallboard and roofing - to some degree.

As a side note, we replaced our windows 3 years ago with triple pane low-admittance glass, and replaced our air conditioner last year. It's now a little more powerful and used about 1/2 the energy to do the same work. And it only runs half as often. The only downside has been during the winter where the sun doesn't heat the house as much and we have to run heat - but here in San Diego that's not much cost.

Let's use some numbers (no math I promise) -

Let's say your house is average sized. That means it's receiving about 170 kilowatts of sunlight at noon. Most of that is converted to heat. Hopefully most of that stays outside due to your insulation - but some is going to make it inside.

A 12,000 BTU air conditioner can remove about 3.5 kilowatts of heat.

That's the battle that's being fought - and your air conditioner is hopelessly outclassed. It can't cool the entire house, not even close. At best it can cool the space you are in - the space INSIDE all the insulation and doors and wallboard and roofing - to some degree.

As a side note, we replaced our windows 3 years ago with triple pane low-admittance glass, and replaced our air conditioner last year. It's now a little more powerful and used about 1/2 the energy to do the same work. And it only runs half as often. The only downside has been during the winter where the sun doesn't heat the house as much and we have to run heat - but here in San Diego that's not much cost.

This has been helpful. I'm realizing that I've been unfair in my expectations of my a/c unit. My frustration perhaps, is when it shuts off due to the condensation pan filling up with water, the house heats up soooo quickly. Every time feels like the first time, and it's as though I need to learn this lesson, again and again.

My outside a/c unit was replaced last year as well, but maybe it'd be worth looking into ''low admittance glass.'' My house is well insulated, so perhaps this would be a good investment considering it's extremely hot roughly 5-6 months out of the year. It could be that my a/c is just running too long throughout the day without a sufficient break?

If it didn't keep shutting off you wouldn't be thinking about this. I'd figure out why the condensation tube keeps getting clogged up. Maybe you also need a more powerful a/c for the size of your house. Better windows, although expensive to buy and have installed, probably would be worth it given your climate.

As a kid, from eastern NC (very humid) when I went though your state on vacation, I thought "how does anyone live here" unless it's right on the coast. And I thought NC was bordering on unboreable.

Yes, the pan is overflowing and there is a “floating” valve that once it’s triggered (due to the overflow of pan water), it shuts the system off. An a/c tech usually runs a water line/hose through the pipe to push the clogged area out; sometimes a “gelatinous” blob flows out through the exterior pipe outdoors, which is apparently a build up, common during this time of year. This is one of the reasons I’m kind of over the Southeast; the summers are smothering hot.
Normally the pan is angled in such a way that excess condensation drains out to the outside via a pipe. That's what ours does. We also have it serviced once a year to disinfect the pan and drains, as it's a breeding ground for bacteria. I've never noticed anything but clear water coming out of the overflow drains for ours outside. I don't know why yours is throwing out a gelatinous blob. To me it just sounds like the pan is not installed properly, in that it hasn't been angled correctly to continuously drain.

As for your other issues.. Consider what insulation there is in the roof and walls. While walls would be too hard to do now without stripping off the plasterboard, etc, roof insulation can be rectified. Also consider what ventilation is in the roof to allow the hot air that rises to escape.

I live in the sub-tropics and for most of the year, it is terribly hot and humid. We have air-conditioning to pretty much the entire house, but we also have good roof insulation and wall insulation as well, which helps a lot (especially the roof insulation!). As well as fans (we have a lot of fans through the house, which does so much in keeping the house cool). Roof ventilation, we have whirly birds and ventilation under the eaves which draws out a lot of hot air from the house). I also have external shutters on windows (can also use awnings or if your house has verandas or deep eaves, can help quite a bit) or you can plant trees to shade the house and windows. Because of the insulation and passive cooling methods we have, we don't really need to turn the a/c on unless we're in a heatwave to be honest.. Even on super hot days, the fans and passive cooling we have in the house, we don't feel it as much inside. When we do turn on the a/c, it's quicker to cool down the house.

Normally the pan is angled in such a way that excess condensation drains out to the outside via a pipe. That's what ours does. We also have it serviced once a year to disinfect the pan and drains, as it's a breeding ground for bacteria. I've never noticed anything but clear water coming out of the overflow drains for ours outside. I don't know why yours is throwing out a gelatinous blob. To me it just sounds like the pan is not installed properly, in that it hasn't been angled correctly to continuously drain.

As for your other issues.. Consider what insulation there is in the roof and walls. While walls would be too hard to do now without stripping off the plasterboard, etc, roof insulation can be rectified. Also consider what ventilation is in the roof to allow the hot air that rises to escape.

I live in the sub-tropics and for most of the year, it is terribly hot and humid. We have air-conditioning to pretty much the entire house, but we also have good roof insulation and wall insulation as well, which helps a lot (especially the roof insulation!). As well as fans (we have a lot of fans through the house, which does so much in keeping the house cool). Roof ventilation, we have whirly birds and ventilation under the eaves which draws out a lot of hot air from the house). I also have external shutters on windows (can also use awnings or if your house has verandas or deep eaves, can help quite a bit) or you can plant trees to shade the house and windows. Because of the insulation and passive cooling methods we have, we don't really need to turn the a/c on unless we're in a heatwave to be honest.. Even on super hot days, the fans and passive cooling we have in the house, we don't feel it as much inside. When we do turn on the a/c, it's quicker to cool down the house.
Therein lies part of the problem with the condensation pan in my unit - it’s not on an angle, nor are the pipes leading out of the house. It’s a construction flaw for sure, and it creates this “bacteria sludge” to form and stagnate in the pan and it seeps into the pipes, and doesn’t flow fast enough because they’re not on an angle. But, I’ve found something that’s been helping - condensation tablets. You place a few in the pan and it stops the sludge from forming to begin with. Fingers crossed, doing this biweekly will stop the system from shutting off.

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Therein lies part of the problem with the condensation pan in my unit - it’s not on an angle, nor are the pipes leading out of the house.
I suspect Bells is talking about a window unit. Central units don't have their pans on an angle, but they do have pans that have a depression that everything drains to, then goes outside.

You're going to have to fix the drain angle thing eventually. Sometimes it can be as easy as removing a short section of pipe by the downtube so that there's a greater slant in the tube from the tray. Sometimes it requires a little woodworking to route the tube a little more effectively. A last ditch solution is a local sump with both a pump for the condensate and an emergency overflow in case the pump stops working.