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New Air Conditioner Process Cuts Energy Use 50-90%

Posted by kdawson on from the tortured-backronym dept.

necro81 writes "The US National Renewable Energy Laboratory has announced that it has developed a new method for air conditioning that reduces energy use by 50-90%. The DEVap system (Desiccant-Enhanced eVaporative air conditioner) cools air using evaporative cooling, which is not new, but combines the process with a liquid dessicant for pulling the water vapor out of the cooled air stream. The liquid dessicant, a very strong aqueous solution of lithium chloride or sodium chloride, is separated from the air stream by a permeable hydrophobic membrane. Heat is later used to evaporate water vapor back out — heat that can come from a variety of sources such as solar or natural gas. The dessicants are, compared to typical refrigerants like HCFCs, relatively benign on the environment."

2 of 445 comments (clear)

  1. Good for server farms? by tagno25 · · Score: 5, Interesting

    Heat is later used to evaporate water vapor back out — heat that can come from a variety of sources such as solar or natural gas.

    or the servers that are being cooled?

  2. Re:lithium chloride or sodium chloride? by Anonymous Coward · · Score: 5, Interesting

    You need to do more research. You can put R-400 in the walls and it won't help, because you are dealing with a building that has windows and occupants.

    In most places, solar heat gain is a major component that A/C has to deal with. Humidity in the makeup air is also a large problem for A/C to handle.

    Humans inject heat and water vapor into the building through cooking, respiration, appliances, and opening doors.

    Humans also need fresh air, and you can't -- legally or practically -- build an air-tight building without makeup air.... which introduces more humidity and heat into the building envelope.

    I built my house 2 years ago and used all closed-cell spray foam (isocyanate) making all walls, floor, and roof, water-tight and air-tight. 133 mm of foam gives me R-37 in the walls, and more gives me R-60 in the floor and ceiling. All ducting is in conditioned space. All external walls have thermal breaks (offset studs). I have an ultra-efficient water-jacketed earth-coupled geothermal heat pump. The solar gain in the summer still rapes my house with heat gain. The makeup air I have to have because the house is so damn air-tight, uses a high capacity heat exchanger, but still is a water-vapor sieve pumping water vapor into the conditioned space that the A/C has to then remove.

    So do a little more research before you spout off with drivel.