Questions on moving air?
Questions on moving air?
(OP)
Hello. I am working on a project to cool down an enclosed environment. The volume is approximately 300 cubic feet using a ventilation system mounted on the top. The environment is watertight but not airtight. It can reach temperatures up to 140 degrees Fahrenheit internally with approximately 100 degree Fahrenheit externally. I have two questions for this situation . Approximately how many cubic feet per minute would I need to move to achieve a temperature of approximately 80 degrees with no active cooling systems, and would this be feasible? And would it be easier to move air in then out, or just to evacuate air from the environment? I am an electrical engineer and do not know a whole lot about HVAC and related fields so I appreciate your help and replies. thank you





RE: Questions on moving air?
In which case you would need to know the wattage of any equipment working in the room, because you are going to have to remove the heat generated by that.
Sun radiation alone will bring an uninsulated room up to 40*f above the ambient air temperature, especially if it has windows the sun can shine into and it is painted with dark paint.
In some parts of the world, evaporative coolers can cool quite well at not too much cost, if the relative humidity is not too high.
Give us more information and you will get a more sensible answer.
B.E.
You are judged not by what you know, but by what you can do.
RE: Questions on moving air?
I don't understand why you're trying to be so sophisticated here. Just stick a 4" fan on the inlet and a similar sized outlet and blow in relatively cold air.
Your temp won't fall below about 110F at best.
All depends on how much heat your equipment is generating.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Questions on moving air?
This is of course an active cooling system which you were trying to avoid!
RE: Questions on moving air?
RE: Questions on moving air?
RE: Questions on moving air?
RE: Questions on moving air?
B.E.
You are judged not by what you know, but by what you can do.
RE: Questions on moving air?
These work by running during the night when the air temp falls and blowing air through a large metal block. This gradually reduces the temperature of the block to the ambient air. As soon as the outside air temp increases above the block temperature you turn that fan off and start an internal fan which blows air through the block and around the enclosure. You might need quite a big block of metal, but is something I've looked at for remote solar powered instrument kiosks.
Your real issue though sounds like solar gain where some sort of insulation is a must otherwise you will always be chasing your tail. There are some very effective thin insulation materials around which will help a lot.
There are some solid state cooling units around with realtively low power needs and if the key itme to keep cool is the computer, try something like this http://204.12.46.198/2010/applications/ac.htm
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Questions on moving air?
RE: Questions on moving air?
B.E.
You are judged not by what you know, but by what you can do.
RE: Questions on moving air?
Berkshire, Oh i know they used to kill my electric bill. I dont really know much about active cooling systems, other then they usually require a significant amount of power.
RE: Questions on moving air?
There are some small solid state air conditioners that are made for computer enclosures Most of them use Peltier diodes.
There are also some miniature 12 or 24 volt air conditioning compressors Originally made for military use that cool computer enclosures.
You may be able to repurpose one of these to cool your batteries. Talk to a professional.
http://www.bing.com/images/search?q=12+volt+air+co...
B.E.
You are judged not by what you know, but by what you can do.
RE: Questions on moving air?
RE: Questions on moving air?
Chicopee, I understand why LPG tanks are white. They reflect heat. When I was asking my friend questions about his structure and why it was dirt brown his answer was "So it would not create to unnatural of an object". Using shade canopys isn't to bad of an idea since they can lower the temperature of a surrounding area, but I don't know what he's measuring and how it could effect it. I will suggest it though. Misting is a nice option, I like the misted lines at Disney land, but California is in a drought and that's not something im too knowledgeable on.