COLD COMFORT: The chlorofluorocarbon coolant widely used in air conditioners throughout the 1980s was phased out because it was damaging Earth's protective ozone layer, but the chemicals that replaced it are some 2,100 times stronger as greenhouse gases than carbon dioxide. We may have saved the ozone layer, but--whoops!--there goes the climate.
Image: Photos.com
-
The Best Science Writing Online 2012
Showcasing more than fifty of the most provocative, original, and significant online essays from 2011, The Best Science Writing Online 2012 will change the way...
Read More »
Dear EarthTalk: Has an alternative to air conditioning to keep rooms cool been invented that is significantly cheaper and/or uses significantly less energy than traditional air-conditioning?— Ashutosh Saxena, Allahabad, India
Unfortunately the modern day air conditioner, with its constantly cycling, energy-hogging compressor and environmentally unfriendly chemical coolant, still reigns supreme throughout the world—and increasingly so in rapidly developing countries like India and China where possession of air conditioning connotes middle class status. And while the chlorofluorocarbon coolant widely used in air conditioners through the 1980s was phased out because its emissions were causing damage to the globe’s protective ozone layer, the chemicals that replaced it worldwide, and which are now in use in hundreds of millions of air conditioners, are some 2,100 times stronger as greenhouse gases than carbon dioxide. We may have saved the ozone layer, but—whoops!—there goes the climate.
Just because people aren’t using them much doesn’t mean there aren’t some good alternatives. The best known is an evaporative cooler (AKA swamp cooler). Better for hot, dry climates, these electrified units cool outdoor air through evaporation and then blow it inside. They make for a nice alternative to traditional air conditioners, using about a quarter of the energy overall. They are also quicker and cheaper to install, and can be moved around to different rooms as needed. But swamp coolers can require a lot of maintenance and may not keep the interior space as cool as some AC-hungry inhabitants might like.
Apartment/condo and commercial/industrial buildings might consider augmenting their existing roof-top air conditioning systems with the cooling power of ice. California-based Ice Energy makes and sells the Ice Bear system, essentially a large thermal storage tank that makes ice at night—when the cost and demand for energy is lower—and then doles out ice water into the air conditioning system during the day to efficiently deliver cooling when it’s needed. Since the air conditioner’s energy-intensive compressor can remain off during peak daytime hours, the electricity required for cooling can be minimal, with some customers achieving 95 percent electricity savings using the system. And utilities across the country are starting to encourage its use by large customers.
Stanford University has been utilizing its own version of similar technology since 1999 to keep its campus buildings cool. Since upgrading to an ice-based cooling system, Stanford saves some $500,000 a year on its campus cooling bill. If such technology could be adapted to augment home air conditioning systems, it could go a long way toward reducing air conditioning’s environmental footprint overall.
Of course, let’s not forget that a small investment in a fan or two to create a breeze or wind tunnel through inhabited interior spaces can go a long way to offset summer heat. Even better, get a professional to install a “whole-house fan,” which draws in cooler air through lower level open windows and exhales hotter air through specially designed attic vents synced to open when the system is operating.
The race has been on in the air conditioning business for some time to find a coolant that doesn’t destroy the ozone or add to global warming, but progress has been slow. Meanwhile, global warming itself will beget the need for more air conditioning, which will only exacerbate an already dire situation, especially as the rest of the world starts to demand artificial cooling just like we’ve enjoyed in the West for decades.
CONTACT: Ice Energy, www.ice-energy.com.
EarthTalk® is written and edited by Roddy Scheer and Doug Moss and is a registered trademark of E - The Environmental Magazine (www.emagazine.com). Send questions to: earthtalk@emagazine.com. Subscribe: www.emagazine.com/subscribe. Free Trial Issue: www.emagazine.com/trial.
See what we're tweeting about
20 Comments
Add CommentSoo... this whole article is actually product placement for ice-energy.com? Way to keep it classy, SciAm!
Reply | Report Abuse | Link to thisGreat article. I would like to see more like this one that give inventors, entrepreneurs, and consumers more ideas.
Reply | Report Abuse | Link to thisI found it interesting that this was more of a blurb than an actual article. I'll chalk it up as a reply to a question.
Reply | Report Abuse | Link to thisThere was unfortunately no mention of heat-pumps or geothermal, both of which, while not super popular, widely used, especially paired with other cooling devices, like swamp-coolers and fans. Air movement will do a lot to cool an area as well as keep the cooling cycle in a place at a minimum since you are then using the laws of thermodynamics to recycle cooler air to warmer areas.
Just some thoughts.
Soo... the parts of the article that actually talked about ice cooling, talked about ice cooling. The bulk of the article (which does not) does not. What were you reading? Way to keep it classy, spork!
Reply | Report Abuse | Link to thisThe most efficient way of keeping cool wasn't even mentioned. Rather than trying to pump heat out of an interior space, the best method is don't let it in to begin with. Insulate and seal. Use light-colored roofs and walls and low-E windows (and no huge expanses of glass). Put shades over windows that reduce the sun hitting the window during the summer, but let more in during the winter when the sun is lower in the sky. Attic fans (which were mentioned) can keep the temperature differential between that space and the living space as low as possible which minimizes heat transfer through the ceiling. If you reduce the heat that gets into a structure, you can use much less energy getting the remaining heat out. Besides, the insulation also helps in winter.
Reply | Report Abuse | Link to thisGood points all Bob. When I was young I lived in an adobe home which was always cool in the summer. It had small windows and thick walls which blocked a lot of light from hitting the windows.
Reply | Report Abuse | Link to thisMy parents bought a house just up the street that was wood framed and had lots of sliding glass doors. It was a hell hole in the summer in So. California.
I was born in Texas in 1950, before air conditioning became ubiquitously available. I suffered during summer months using enormous attic fans and evaporative coolers. They were reasonably effective during the spring & fall, anyway.
Reply | Report Abuse | Link to thisBack in those days in the South, it wasn't just the dogs that suffered the 'dog days' of summer - most couldn't muster enough energy to do much during the summer, and couldn't sleep much at night. What is it they say about good intentions?
Another strategy is seldom mentioned: Some decades ago it was decided that the entire house should be heated or cooled to about 72 degrees. Codes required/encouraged venting in every room. I prefer the model of 'defensible space'. Sunroom, entry, storage, unused areas are not necessarily heated or cooled. Central living space is kept comforable. Less used room less heating and cooling. Ducting can be modified do most of this and with a single thermostat. Strategies would of course need to be modified for different climate areas. We do this with a heat pump of about 1/4 of the size that would have been recommended for a house of our size 30 years ago. More elegant looking and quieter split units (such as I frequently saw in SE Asia) could eliminate the need for expensive ducting and installation costs.
Reply | Report Abuse | Link to thisThis was interesting enough, but I found two major omissions. The first is a very old way of cooling that is coming back into use again. That is geothermal cooling. Here where I live, it was used back in the early days of the city to cool many buildings including those on our University campus. Along the way the change was made to air conditioning. But now, renovation on many older buildings in the city are bringing back geothermal cooling as the best long term choice for our pocketbooks and our environment.
Reply | Report Abuse | Link to thisThe second option is the one I am currently using. I have moved into a two bedroom apartment that utilizes two heat pumps for heating and cooling year round. They are set on independent thermostats so I can adjust them as needed for each area. I moved in during the coldest months of winter and am now her in this long heat/ozone advisory. My utility bill for an all electric apartment including washer/dryer, oven, cooktop, dishwasher, microwave, two televisions, well you get the idea, my bill has so far averaged $39.00 a month. I think I'll be staying with heat pumps.
Although a short response, I found this interesting because I had never heard of storing ice at night during off-peak, which seems a great idea and is in practice a very good one so far.
Reply | Report Abuse | Link to thisOthers have chimed in with some other alternatives, finally some good discussion :). I have a question, I have always wondered about how effective/practical personal cooling system/outfits would be? I know they use them in the Abrahms, have always wondered if that could be expanded upon in a practical way.
Bob and Rob have it right. It's not so much A/C eff but the massive amounts of badly built, not insulated buildings kept below 80F or above 65F that is the problem.
Reply | Report Abuse | Link to thisOne has to consider the site too. In some areas like Fla, etc, south, a white roof would be great, in others like Minnesota, not so much.
I live in Tampa Fla and only using 1'' of urethane foam and galvanized roofing only had a $30 electric bill last month. But I bought under an old oak forest and run both A/C and fans plus eff appliances. Though it does include charging my EV's too, my only transport.
I'm moving and just 1kw of PV handles both my A/C and other needs on my 32' trimaran sailboat including it's motor power. Saving energy cam be both profitable and fun if you do it right.
I wonder if the expense of creating the ice was included in their calculations. Two feet below our feet ie the ground stays a nice 60 degrees year round. Why not just build in the earth, I've been interested in underground housing for years but seems no one is really interesting in a home that require little to no heating or cooling. Not to mention properly built it will stand for hundreds of years.
Reply | Report Abuse | Link to thisSmall supportive exosuit, such as Honda's legs, combined with sealed suit and a pico version of an AC unit, and you've got yourself a suit that you could walk around the Mojave in for a few hours at a comfortable 75 degrees. Ever seen the anime called "Desert Punk"? Same concept is used all throughout that show.
Reply | Report Abuse | Link to thisImagine a vest with cold-water hoses in it. Hoses about half an inch in diameter, made of a thin, water-tight material, zig-zagging through the vest.
Reply | Report Abuse | Link to thisEvery couple of hours or so you connect a hose that sticks out of the vest to a cold-water faucet, and flush through the zig-zagging hoses with new cold water. You let the old, warmed water flow out through another hose that sticks out of the vest. Faucet water will be cool if the water pipes run at a depth where the water gets cooled.
Or if you prefer, you could have two vests, and wear one while the other sits in a special refrigerator, getting cooled. When the one you're wearing gets warm, you switch vests.
Under the vest you carry a t-shirt of just the right thickness so that the cold vest gives you the cooling effect that you want. Above the vest you carry a shirt.
I think this would keep you nicely cool at a very low cost in both money and energy. On very hot days it might save lives.
Regarding refrigerants when the world gets serious about global warming we'll go back to where we started:ammonia.
Reply | Report Abuse | Link to thishttp://www.goodway.com/hvac-blog/index.php/2009/08/ammonia-as-a-refrigerant-pros-and-cons/
i had read somewhere about an ultrasound vortex generator in which hot air flowed one way and colds flow another the other and never heard of it agian.And I saw another device that uses compressed air to do the same thing.If anyone has more information about these please respond.
Reply | Report Abuse | Link to thisOur house has no floor insulation, so in winter it is relatively warm and in summer relatively cool. This reducing heating and cooling bills, and requires little energy input. This is conventional wisdom...
Reply | Report Abuse | Link to thisI'm old enough to remember when air conditioning was a luxury that only the wealthy could afford, and few of us were wealthy. Here's how it's done:
Reply | Report Abuse | Link to this1. Use fans. They use much less electricity and no ozone-depleting and globe-warming chemicals. Box fans, window fans, stand fans. One of my teenage initiations into manhood was helping my late father get the heavy window fan down from storage and install it in the window in May, then the reverse in October.
2. Sprinkle ourselves with cornstarch-based baby powder. It absorbs sweat.
3. Strip down to short pants and sleeveless undershirts or tank tops.
4. Drink like a fish, and I don't mean alcohol, especially when playing outside, which keeps body fat down. Fat is an insulator that traps body heat.
5. Don't think about your discomfort, if any. Distract yourself with a good book, beautiful music, quality time with those you love, all with the fans whirring. Bear life's little annoyances with manly stoicism, and avoid the company of whiners and kvetches.
To this day, I very seldom have need for artificial cooling.
Get the A/C machine off the floor and re-positioned near the ceiling for better and more efficient cooling.
Reply | Report Abuse | Link to thisTwo other options not mentioned, but valuable: first, planting deciduous trees, especially on the south and west sides of the house or building provides cooling shade in Summer but lets the Sunlight through in Winter when it is more appreciated. Second, roof gardens (most practical on buildings with flat roofs, which is unfortunately not most houses), can block heat from entering through the roof and add some evaporative cooling. In cities, both trees and roof gardens also help keep the external air cooler, which means that any cooling system used will not have to work as hard or use as much energy.
Reply | Report Abuse | Link to this