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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."
It's cheaper than using trained hydrophobes. Or are they used to create the membrane?
Nae king! Nae laird! Nae yurrupiean pressedent! We willna be fooled again!
So when will we be able to buy one of these? I know my wife is going to be asking for an AC in the house this summer, and I'm sure that the people in places like AZ, NM, and TX will be clamoring to lower their electric bill.
Additionally, will the dessicants (or the filter) have a recycle lifespan, or will it be more like a traditional household AC, using a 'simple' radiator device?
~/ssh slashdot.org ssh: connect to host slashdot.org port 22: too many beers
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.
For starters, Americans should start insulating their houses better. That would cut the energy costs even more.
Sheesh, RTFA, already. They mention the coolerado and explain exactly why this new idea has the potential to do better.
Or, maybe,
As TFA states, desiccant cooling has been known since at least Carrier's work at the turn of the 20th Century. The trick has always been to make a practical desiccant cooling system.
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.
Few people have heard of the true inventor of both air conditioning and the artificial ice machine, Dr. John Gorrie, of Apalachicola, Florida, who received the first patent (number 8080) for a machine to make ice, on May 6, 1851. While it was reduced to practice (he used it to cool the rooms of his fever patients, and gave iced drinks to his guests at parties -- a fantastic novelty in 1850s Florida) he was unable to make a financial success of the venture. His machine was the first to make use of the refrigeration method of air conditioning.
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.
I don't think the researchers anticipated tha eventuality that somone would open up one of thier units and drink the liquid inside.
So if they don't do stuff like that, then whats the point of having grad students?
Monstar L
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.
Your argument is bogus. R30 fiberglass bats are 9 1/2 inches thick. Are you saying to frame the walls with 2x10s. You know the cost of dimensional lumber increases geometrically with dimension, right. Or do you stagger frame with 2x6s...basically build each wall twice and double your labor costs?
What about existing structures? Because the US market has enough backlog of existing structures. Do you build another layer of insulation INSIDE the house and lose a foot of floorspace near each exterior wall..and then pay to reframe, drywall, move out electrical outlets, etc? Or do you reframe the exterior of the house and then cover and weatherize your new outside envelope?
In either case, what about windows and doors? You do know that heat will gladly take a parallel path. Third-year ME heat transfer class...remember the resistor analogy? You can make the walls R300 and the heat will still get in (out) through "holes in the bucket." Have you priced super high R glazing options? Do you want a 8" thick front door? Even in the walls themselves, you have to worry about thermal bridging through the wood studs...all these would be problems even with some crazy aerogel insulation that is R50/inch.
The building standard is what it is for a reason. It is an engineering trade-off between cost and performance. R30 in the ceiling and either 2x6 walls with R18 or 2x4 walls with R11-12...and maybe a dense insulation board on the outside before siding is installed. Double pane insulated glass windows. Now those trade-offs were in considered with energy and HVAC hardware costs at a certainly level. And more insulation is good but only to the point. The insulation costs goes well beyond the price of the insulation bat, and a point exists where adding more makes no financial sense. If you *insist* on having windows and doors, it doesn't make engineering sense anymore either. Your recommendation is well past that and smacks of niavete. Build or remodel a house or two (especially using your OWN MONEY) and then get back to me. A home built to your bogus specifications would cost four or five times more. I doubt you could find someone to build it for you.
If you want to look into green houses, then look into earth bearmed homes, rammed earth homes...building underground, using lots and lots of earth as thermal insulation and thermal mass. Folks have been doing this since the 70s and there are books that give some good overviews. I'd like to see the building codes revised to make it easier to build some of these different "hippie" houses.
And in sunny climates, I think the best ROI would be a 100x100 white canvas tarp and support structure to shade your entire house. I'm surprised no one does that. That would effectively remove the direct radiation load from the cooling...which is significant...just ask your barefeet after a walk across sunlit asphalt.
no they dont. 4" exterior walls are common now. it USED to be 6" was required for exterior walls. but contractors wanted to increase profit margins clamored to make houses more "shitty".
Homes should also be sheathed with 3/4" plywood instead of the craptastic fiber board they use now. I've been doing high end installs of whole house audio in $1,000,000+ homes on the side for 5 years now. Home construction has went down hill quite a bit from the late 80's where you had to have good construction quality.
Do not look at laser with remaining good eye.