Water or Air As A Refrigerant
The simplest, and most popular, refrigerant is water. With an excellent toxicity profile, extremely low cost, vast availability, and no need for disposal worry, anybody can build a water-based cooling system. The simplest cooling systems, known as swamp coolers in the south-west United States, do not even need power for a compressor, merely a blower fan - evaporated water is simply vented to the living space, where it serves to increase humidity also. However, drawbacks are multiple and severe as well. The total cooling power of the units is limited by the fact that neither coolant nor air is recirculated. A swamp cooled home will have a constant supply of fresh, not too-dry air, but if the air outside is already humid, cooling power is severely limited. This is why such units are not found in areas of frequent and high humidity, such as the south-east United States. Furthermore, if the temperature outside is severely too hot, such as over 110 degrees F, the unit will not cool the air sufficiently for comfort even if the dew point outside is very low.
While the vast majority of the greenhouse effect is due to water vapor in the air, the amount of water added to the air by swamp coolers is insignificant compared to that which evaporates from the world's oceans, giving swamp coolers a very earth-friendly profile.
Famous quotes containing the word water:
“A kind heart he hath. A woman would run through fire and water for such a kind heart.”
—William Shakespeare (15641616)