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Can dry ice be used to cool a the air in a room for a few hours? If so, how would this be done?
If you mean can you cool the air in a room by letting dry ice
evaporate, the answer is yes. The evaporation process itself takes in
heat and the CO2 that comes off is still much colder than room
temperature. However, this doesn't sound like a smart way to keep a
room cold. The normal concentration of CO2 in the air is much less than
a percent. If you evaporate enough dry ice to cool the room much, there
may be too much CO2 around for your health. It's not acutely toxic like
CO, but you still don't want to breath too high a concentration of it.
For more information, you can Google 'CO2 toxicity'. Of course,
ventilation would defeat your purpose. You could, however, use the dry
ice to cool some coils which then cool the air in the room.
(published on 10/22/2007)
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