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New Air Conditioner Process Cuts Energy Use 50-90%
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."
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?
Swamp coolers use a LOT of water. Is this better than them in terms of water use? If not, it's just trading one environmental ill for another. The places that have water to spare also have humidity high enough that even this system might not do so well with its evaporative cooling, and the places where evaporative cooling works best don't have the water to spare.
Sheesh, RTFA, already. They mention the coolerado and explain exactly why this new idea has the potential to do better.
I lost interest at this point. Wake me up when biochemists and medical doctors get a chance to run test case groups about the adverse effects of lithium in their localized atmosphere, typically inhaled into the lungs and later causing one's sense of reality to become skewed.
Well what about the Sodium Chloride option. People have lived near oceans without adverse effects.
I know my wife is going to be asking for an AC in the house this summer
Really? Another one? I've been visiting her for months.
I lost interest at this point. Wake me up when biochemists and medical doctors get a chance to run test case groups about the adverse effects of lithium in their localized atmosphere, typically inhaled into the lungs and later causing one's sense of reality to become skewed.
In order to get lithium chloride vapor in the atmosphere, one would have to raise the temperature to about 1600 Kelvin at normal atmospheric pressure. Under those conditions, I propose blind panic as a suitable coping strategy.
A desert is an ocean with its life undergound, and a perfect disguise above.
Or is it the other way round?
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
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.
When I was young we had no AC, and this was in rural southern Africa, so it was usually very warm during the day.
I live in an old farm house in the US now and though it has central AC I very seldom use it. Usually when I have guests because if I don't they immediately comment on how hot it is and how can I stand it and that they are sweating just standing still. They threaten to swoon. They forecast their own death. They google map the closest hotel.
I built a cabin on the other end of the property and it is similar to what you describe. (it is a Kundig design, which tend to be pretty green) People who visit still complain when the AC is not on, but only when it is particularly hot and humid outside.
Anyway, I think it is a combination of dwelling design and the fact that people in the US are so used to conditioned indoor air. Even at 90F there is little real physical risk to anyone other than the elderly, but I have met plenty of people who simply can't tolerate it mentally.
"Sacrifice for the good of The State" - The State
As a home designer, I resent that remark.
Seeing as I lived and breathed in that field, I can tell you that just about every architect or designer gets a excited at the idea of sustainable, high energy efficient homes, built right to suit the local environment. So these "idiot architects" you rave about don't exist. Since you're obviously ignorant, let me inform you of the real problem. The general public.
Anything other than a "McMansion" just won't sell to the vast majority of Americans. When the home buyer has a limited budget, they have to balance their wants with their needs, and often you will find that features such as low e windows, good insulation, large overhangs, large thermal mass, etc... They might not always compete when compared to that extra bedroom, the outdoor jacuzzi the wife's always wanted, or that extra bay in the garage. Saving $25 a month on a heating bill may be a priority, but in the big picture, it's rarely priority #1.
Personally I love the idea of efficient and sustainable homes, but for one reason or another, clients who are willing to pay for that kind of thing are rare.