Float tank ventilation

Discussion in 'Architecture & Engineering' started by Waldomiro Junior, Nov 2, 2014.

  1. Waldomiro Junior Registered Member

    Messages:
    8
    Hello


    I built an underground room measuring 2,5m x 3m x 2,3 just below the ground, the walls are about 20cm thick in solid concrete, the ceiling has iron structure and semi hollow bricks in the concrete, the whole room is revested in ceramic and porcelain tiles inside, the entrance is a 80cm x 80cm opening on the floor and it´s "sealed" with a wooden door. Its a flotation tank (among other names), its basically a concrete with ceramic tiles tub measuring 2,3m x 1,2m x 40cm. It´s used in sessions of 1 or 2 hours (I was thinking about longer sessions) and it should be isolated from light and sound, but Im afraid of the quantity of O2 and CO2. The room is not perfectly sealed, it has 6 "pipes" in the walls that carries the electrical wires (the pipes are long and they make many curves.
    I read somewhere that CO2 from breathing accumulating in the room is more urgent than the lack of oxygen itself, that CO2 is heavier than the air, so does it accumulate from the floor up? Because if it does how should I remove it if it´s already an underground room? I cant use collers because the sessions have to be made in complete silence; I thought about making 1 or 2 holes on the door with pipes making curves inside de door, will this add enought O2 to offset the breathing (by the way the person using is completely relaxed), and will it remove the CO2 since supposedly it´s on the floor because it´s heavier than the O2?
    Its in Brazil so the weather is tropical most of the year. The water in the tank is 24 hours heated at about 37 celsius, it has about 700 liters of water with about 400kg of epsom salt (magnesium sulfate). Does this water affect anything in the ventilation matter?


    Sorry for the long text, there is no easy way to explain without giving details. Any idea is appreciated.
     
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  3. Landau Roof Registered Senior Member

    Messages:
    598
    Perhaps photographs would help us to understand.

    Are you telling us you took all the time and trouble, and money, to build this floatation tank chamber but you did not plan the ventilation system? Do you live in a country where government inspectors and building permits are unnecessary? And what are 'collers'?
     
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  5. Waldomiro Junior Registered Member

    Messages:
    8
    I dont have my camera now, as soon as i take some pics I ll send them.
    Sorry, I meant coolers, like those computer fans.
    My plan was to use in 1 or 1 and a half hour sessions, and in this case according to my calculations there will be no problem with o2 or co2. But now I´m thinking of having longer sessions like 4 or 5 hours for super learningn but in this case I´m worried about co2 especially, which I also have a plan; using 2 pipes 1 for air intake and the other outtake, and I would turn on the fans from time to time, like every hour, but every hour the sound of the fans would disrupt the experience, and also I don´t know how long I would have to turn the fan on so that the air would be renewed, so I m asking if anyone has a better idea.
    The permit I have from the city hall is for an underground warehouse, if I told them it would be for a float tank I would have all kinds of problems because nobody here even knows what it is, and I don´t want to discuss this with people who want to be against something they never even heard of.
     
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  7. Landau Roof Registered Senior Member

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    598
    Well, City Hall would have no objection to you breathing in your warehouse, would they? Did they not ask that you adhere to some ventilation regulations for plain old human habitation?
     
  8. Waldomiro Junior Registered Member

    Messages:
    8
    They asked for it, and I showed them the pipes and fans and they were ok with it.
     
  9. Landau Roof Registered Senior Member

    Messages:
    598
    Then, that's probably enough air for one guy relaxing in a tank for a few hours, right? The room can't be very small if it's a warehouse.
     
  10. OnlyMe Valued Senior Member

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    3,914
    This may not be the best advice. Unless you specified that you would be lying down and breathing air at floor level, a warehouse and float tank would have little in common.

    I don't have an answer, to the CO2 problem, but suggest that it would be wise to either consult someone with practical experience with float enclosed tanks or if possible even design plans form commercially available float tanks.., or as sometimes referred to sensory isolation or depravation tanks.

    As mentioned in the OP the issue is CO2 build up at the floor or water line, just where an occupant would be breathing. That is not something a building inspector or plans examiner would be expecting unless they knew the purpose of the tank/warehouse.

    Try searching for isolation tank design/plans some commercial tanks use air circulation by convection, rather than fans, which would address the fan sound problem and provide a continous air exchange.
     
  11. Waldomiro Junior Registered Member

    Messages:
    8
    Actually it is small in my case, 2,5m x 3m x 2,3m, but i just showed them the fans so that he wouldn´t fail my building, but I don´t want to use them, they make too much noise for the tank.

    Onlyme, the air circulation by convection is a good idea, I ll research a little more on that, thanks, I have looked for plans, but they are all to use as a tank, in my case because it´s an underground room I´m afraid it won´t apply to the same physics.
     
  12. OnlyMe Valued Senior Member

    Messages:
    3,914
    Air circulation and a freash air exchange are important. The big problem is that without circulation CO2 will build up at the water level, right where you are breathing. If the CO2 to O2 concentration swings to far toward CO2 it becomes dangerous, even fatal. The smaller your total air space the greater the danger.

    Be careful!
     
  13. brucep Valued Senior Member

    Messages:
    4,098
    You're going to have to ventilate the room sometime. I have a CO2 monitor in my grow room. For monitoring CO2 enrichment. With no online grow [no plants] it's amazing how fast the ppm rises just while I'm working in
    the grow room with the ventilation system down. You should familiarize yourself with the CO2 confined space hazards, buy a meter and run a test. You must have a ventilation system for refreshing the environment between uses. Probably during uses also. The ventilation system can be designed to be non intrusive. My grow room is 742 cubic feet. The meter I have is for temperature, humidity, and CO2 ppm.
     
    Last edited: Nov 6, 2014
  14. Waldomiro Junior Registered Member

    Messages:
    8
    2 days ago I bought a co2 meter, but it´s coming from usa to brazil so it will take a while.
     
  15. brucep Valued Senior Member

    Messages:
    4,098
    Keep in mind it's a pretty big number before you get into the danger zone. You just need to know what that is. It's my experience that it tends towards an even distribution [ppm content] throughout the room rather than bunching near the floor due to gravity. Qualify that by saying I have several small circulation fans running plus a 12,000 BTU portable air conditioner discharging over the canopy to control temperature. LOL. All you'll need is a small unobtrusive flow of new air. That should also eliminate any stratification problems. Let us know what you decide to do. Mess around with your monitor. Try sitting in the bathroom for 15 to 20 minutes and watch the ppm double.
     
    Last edited: Nov 8, 2014
  16. Dr_Toad It's green! Valued Senior Member

    Messages:
    1,830
    y stale air pockets, and still keep it nearly silent.

    I had to do that, it just begged..
     
  17. OnlyMe Valued Senior Member

    Messages:
    3,914
    Critical issues are the volume of air space in the warehouse/float tank and some circulation.

    At my last job, we had to use freash air supply equipment or air tanks when working in below ground equipment vaults, specifically because there is no regular circulation. There was one case where an electrician, thought he would be in and out and did not use proper equipement. Had he not been working with a partner, who with air tank went down and carried him out, he would not have survived.

    You were describing a subterainian float tank with no ventilation once closed up... And you did talk about the possibility of extended sessions.

    Again be careful.
     
  18. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

    Messages:
    23,198
    There are chemicals that absorb CO2. They have been used for years in submarines, I think. They may be reversible - thermally cleared of the absorbed CO2 - If so, probably a "one time cost" small compared to what you have already spent. I don't know any details - only trying to help with area for you to search.

    A small medical O2 tank can trickle oxygen in but don't over do that.

    I have read some about "sensory depredation." What you are planning is related. So that is a term you should search too. In those experiments, often body is immobilized with only a pound or so of your weight supported by a submerged board /table, rest by bouncy. You would have hands and feet inserted into fixed "gloves." Your body will be generating at least 50Watts that must be removed. Hence water temp needs to be closer to 36 than 37 C.

    With all external stimulation absent or greatly reduced, you will hallucinate, probably in about an hour. Brain when so deprived begins to invent perceptions.* Don't do this alone. I live in Sao Paulo, within short walk of both Ave. Paulista and Brigadeiro. Not sure I am willing to help monitor you, but do have interest in knowing what happens in large part because I think all perception is constructed in the parietal brain. You should learn more and find interesting:
    http://www.sciforums.com/showpost.php?p=905778&postcount=66 where I explain and justify my RTS view of perception with focus on showing genuine free will is not necessarily inconsistent with the natural laws that control the firing of every nerve in your body. Then see:

    http://www.sciforums.com/threads/wh...e-will-an-illusion.104623/page-5#post-2644660 and posts 84,86 & 94 where I clarify my POV more.telling my POV.

    * much like it does when dreaming. In REM sleep, most of the connections to external stimulation are processed but not given (with some exceptions) to the parts that are making your consciousness. That unconscious processing will inform the conscious (dreams are part of consciousness in my POV) part if it is important (alarm clock, some one saying your name, glass window being broken, etc.)
     
    Last edited by a moderator: Nov 10, 2014
  19. Waldomiro Junior Registered Member

    Messages:
    8
    I thought about the o2 tank too, but that still doesnt solve my co2 problem. Somebody told me about those chemicals, Im still researching that option.
    Yes its exactly that, the first name actually was sensory deprivation tank", they have other sensory deprivation solutions, but the tank was the best in my opinion.
    I will read the links you provided.
    Thanks
     
  20. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

    Messages:
    23,198
    I just gave link to your OP at: http://www.sciforums.com/threads/will-machines-become-conscious-someday.118431/page-18#post-3249206 and tested it, so I re-read the OP and had better idea. Yes the CO2 will accumulate in air above the water level (some will slowly acidify the water, but some baking soda (Sodium Bicarbonate, in English & Bicarbonato de Sodio in Brazil) can be added to the water before each secession and the pH checked but my "new idea" is how to silently ventilate:

    With hose that has a U-turn at one end, cheap and black when used with many washing machines, you can get good CO2 removal. I.e. just outside you concrete wall make a hole with a "post hole digger" deeper than the surface level of the water by at least foot. Put* the end without the U-bend below the water level inside say 4 or 6 inch diameter PVC short pipe that is holding the dirt from falling into your dug hole. At top of that short (2 meters?) PVC pipe section you have quiet fan sucking the CO2 up to vent it. If you can hear the fan in the silent tank, put two screen wires below the fan a foot or so apart with big wad of course cloth to absorb sound between the two "diameter large" screens.** At the food market they will give you for free very suitable cloth they get bags of onions etc. in.

    * I hope you made the concrete walls with very "sand rich" concrete mix - you probably did as no need for high strength and much cheaper, as you need small hole thru the wall just above water level to pass the black CO2 venting tube thru. The open end of the U-bend should be about 1cm above the water level. Don't "cap" the bottom end of the PVC pipe - just leave it open to the dirt. Occasionally, when entering you will forget to have turned the fan off and it will suck a little water into the black CO2 venting tube that can just drain down thru the dirt.

    ** A "no fan" alternative can work to: Make the bottom of the PVC tube at least a meter below the bottom of the tank. The back U-tube will allow the CO2 to naturally drain to the lower part and you ventilate it with fresh air each time before enter the flotation tank. I would go with the fan as digging the full depth you can with a post hole digger is hard work and the extra length of PVC pipe cost more than a cheap small fan.
     
    Last edited by a moderator: Nov 29, 2014
  21. alvar van rijn Registered Member

    Messages:
    1
    Curious how far along you've gotten with this.

    I think the solution can be a lot more simple. You already have in and outgoing pipes. There are insulated airvent tubes available. They are specifically designed to absorb noise from airvent systems. Usually aluminium foil on the outside, rockwool on the inside and perforated aluminium foil inside. Use those where ever the pipes come out and use a few meters long. You may need only one end connected. Connect the tube and put it in a ssss shape. That way the sound has to rebound on many surfaces and will dissipate. Attach a silent computer fan to the out end of the tube and let it either suck the air out or blow it in, whatever you like.

    Also you may want to check on Facebook. I've started a group there called Float Tank DIY to discuss exactly this sort of stuff with others.
     

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