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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.
And otherr refridgerants like R-134a can also form deadly compounts when the degrade, but since they are in a closed system they can be used. I don't think the researchers anticipated tha eventuality that somone would open up one of thier units and drink the liquid inside.
quis custodiet ipsos custodes
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
If you're building new, modern building codes result in a more insulated space. In my opinion modern codes -- even those in CA or the "stretch in MA or the base points in LEED -- aren't aggressive enough, but they're far better than existing conditions in most buildings. Of course, the same opportunities exist for major remodeling or work on the exterior.
Sometimes, though, the mechanical unit needs to be replaced, and quickly. In those cases, would you prefer that this new AC not exist (assuming they work out any chemical safety issues)? For spaces which are currently being used, the interruptions caused by upgrading the building envelope may be intolerable, a non-starter. In those cases, would you rather this new AC not exist?
You're absolutely right -- improving the insulation and air-sealing of our building stock would have a remarkable impact on our energy use. Still, this new AC system, if it works as advertised, can be applied to buildings for which an insulation and air-sealing upgrade simply isn't in the cards in the near term.
Adding another tool to the belt isn't a bad thing, as long as we continue to use the right tool for the job. Building codes will help ensure that we do.
Support a few technologists in Washington.
In the street, just like every other air conditioner in the world.
No sig today...
Cause Coolerado uses Flash and TFA HTML5?
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."
Chemist who works with LiCl reporting in (Specifically LiCl enhanced potentiometric buffers).
I won't be using it in my house for a simple reason: If that "membrane" gets punctured you're going to have one hell of a cleanup cost. I won't even go into the aerosolized effects. Check out any SDS.
That's boiling, yes. But LiCl in water can easily aerosolize. Think Nebulizer treatments on a household scale.
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.
That's plain old evaporative cooling, and doesn't work too well in humid climates. TFA describes a method that combines evaporative and dessicative cooling in a novel way, without that disadvantage.
Why would anyone engrave "Elbereth"?
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.
How does it compare with efficiency of propane cooling? For the foreseeable future propane will continue to be created by oil industry, regardless of the idealism of some environmentalists, so it will continue to be used in homes for heating. For cost-saving purposes, propane fridges and freezers are being used quite often in remote areas - they are also extremely efficient. I am curious how the two systems compare in efficiency.
Remember, separate your grad student: Females under the desk, males on the dissection table.
MMO Quests are like orgasms:
You may solo them, I prefer them in a group.
A better way is self expanding foam, it will even insulate homes that have the crappy 1st gen fiberglass batting. it just requires COMPETENT installers so they dont put in too much and burst the walls.
I did an entire 2100 sq ft home for less than $2200.00 that included adding an extra 18 inches of fiberglass batting to the attic. My heating bills dropped from $210 to $80 a month in the winter with a 25 year old 55% efficient furnace. this summer that get's replaced with a 90% efficient furnace.
Do not look at laser with remaining good eye.
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.
Isn't this where the reavers came from? Lithium chloride in the atmosphere to calm the population, caused 99% of the people to give up and die, and sent 0.1% into a psychotic rage?
Oh, right. That was a science fiction movie. I always get those confused with reality.
John
This is a perfect example of how any approach to reducing the carbon should be handled.
Instead of brow beating everyone into paying more for less and prattling on about the environment and how we are all going to die, just make a device that accomplishes what you want while making it cheaper for the consumer.
Reduce Carbon, impact "global warming"...sorry, "climate change", pay more = boring, politically charged, scam written all over it.
Reduce cooling costs 50%-90% = Where can I buy one NOW!?!
This is what you call a win-win.
When Fascism comes to America, it will call itself Anti-Fascism, and tell you to give up your guns.
Do you perhaps mean a row of horizontal studs?
Do you perhaps mean joists?
Neither. The horizontal pieces between the studs are called firebreaks. They are there solely to slow fire down and help prevent it from spreading between building floors vertically through the wall stud space. They don't serve much mechanical structural purpose, but they do also help prevent vertical cold air flow inside the walls which helps the insulation (fiberglass insulation doesn't stop airflow, it just filters out the dust).
The 1920s portion of my house does not have any firebreaks in two of the exterior walls, as it's built using so-called "balloon framing" which used long vertical studs that run continuously from the rim beam on top of the foundation all the way to the attic. Because of this, cold air can flow down the walls from the attic in winter. I've injected firestop foam into strategic parts of the wall to stop this, as I found some parts of the interior wall surface were below freezing last winter.
Putting moderation advice in your
"NREL has patented the DEVap concept ... Eventually, NREL will license the technology to industry"
I thought that inventions that we all paid for with our taxes were public domain. How is it that this government lab will be licensing this technology?
This is another typical over statement. They calculated the efficiency without including the energy that is required to reverse the desiccant used thus the calculation is misleading at best and really just a lie. This seems to be a trend that started with "zero emissions" cars that had the electricity magically appear.
Believe it when you see calculations based on a closed loop system as I am betting that the efficiency advantage will tumble a LONG way.
Calcium chloride is interesting: put a pan of it in a humid room and it dissolves in the water it absorbs. But it also gets hot when it does so, which would seem to defeat the purpose. I wonder how they get around that problem.
I have a house with a similar system (just purchased).
My first house had an 80's correctly sized boiler with natural gas. It was a 1200 sq ft row home.
It cost me more to heat than my new home (both built 1928), with foam blown in and real attic insulation. The new home had a fifties, very oversized, oil boiler. The new home is 1400 sq ft, and both had similar windows (old windows with storm added). At the time gas vs oil was similar per/BTU.
Wow, sent an e-mail as suggested when clicking on "use classic" banner, and got a fast response that addressed my msg