Waste Heat Recovery From Air Conditioners

A restaurant, apartment complex, shopping mall or hotel can save even more energy by connecting Enviro Pacs between the commercial scale A/C and hot water heaters. The saving depends on the size of the AC, its efficiency, how much you run it, and the length of your sweltering hot season.

The Enviro-Pak can improve the efficiency and life of your air conditioner because it pulls out the heat. The AC compressor doesn’t have to work as hard, the AC draws less power, and the work load is reduced. As a result, AC runs more efficiently and can save you up to 15% on energy costs while reducing your carbon footprint.

While these won’t reduce your heating costs as much a solar water heater, they cost much less than solar hot water heaters and are easier to install between your current hot water heater and your A/C system.

Best of all, they supply free heat that you already waste.

And, btw, if you care about those states, you might want to let your Senator know how you’d like them to vote on the cap and trade climate bill, too. At the least, because it will help you pay for low carbon home energy saving systems like these. Just call the switchboard at (202) 224 3121.

We can still avoid the worst catastrophic effects by funding the switch to renewable energy with cap and trade incentives to reduce fossil fuel use. Kyoto-inspired cap and trade legislation is why Europe is now so far ahead of us and uses less fossil energy now. We can do it too. These states already have.

Image from flikr user Eelco Visser

Via Build It Solar and Enviro-Pak

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http://cleantechnica.com/author/susan Susan Kraemer

Great idea. It would be easy to incorporate the savings upfront. One company that does, though is PVT Solar that combines solar pv (electricity) with solar thermal for heat by Vinod Khosla
http://cleantechnica.com/author/susan Susan Kraemer

Great idea. It would be easy to incorporate the savings upfront. One company that does, though is PVT Solar that combines solar pv (electricity) with solar thermal for heat by Vinod Khosla
http://www.olivetreeenergy.com Thomas H. Hebert

With regard to previous comments, first, when an A/C system has additional condenser coil surface added, the efficiency goes up not down (if the friction related pressure loss is low), secondly, refigerators do not have enough compressor horsepower to provide significant amounts of recoverable heat, thirdly there is a waste heat recovery unit that produces more hot water over a years period of time than a pumped heat recovery unit, that has no pump or electrical input whatsoever (go to http://www.olivetreeenergy.com , to see). Finally, the maintenance costs alone, make this system more cost efffective than solar (or pumped heat recovery).
http://www.olivetreeenergy.com Thomas H. Hebert

With regard to previous comments, first, when an A/C system has additional condenser coil surface added, the efficiency goes up not down (if the friction related pressure loss is low), secondly, refigerators do not have enough compressor horsepower to provide significant amounts of recoverable heat, thirdly there is a waste heat recovery unit that produces more hot water over a years period of time than a pumped heat recovery unit, that has no pump or electrical input whatsoever (go to http://www.olivetreeenergy.com , to see). Finally, the maintenance costs alone, make this system more cost efffective than solar (or pumped heat recovery).
http://www.greenlifeanswers.com Dave Kay

The thermodynamics support the claim of improving compressor efficiency. As long as the rate of heat removal to the 55-degree water is greater than the rate of heat removal to, say, the 90-degree air the AC was designed to dump to(which should be the case, given the relative temperatures and heat capacities of the air and water), the refrigerant will return just as cool if not cooler. It really does reclaim “waste” heat.

But I agree that solar hot water heating seems a lot simpler than intercepting the refrigerant on a central AC — and the units might also keep your roof cooler if mounted on the roof!
http://www.greenlifeanswers.com Dave Kay

The thermodynamics support the claim of improving compressor efficiency. As long as the rate of heat removal to the 55-degree water is greater than the rate of heat removal to, say, the 90-degree air the AC was designed to dump to(which should be the case, given the relative temperatures and heat capacities of the air and water), the refrigerant will return just as cool if not cooler. It really does reclaim “waste” heat.

But I agree that solar hot water heating seems a lot simpler than intercepting the refrigerant on a central AC — and the units might also keep your roof cooler if mounted on the roof!
russ

The water heater connection is available from some AC models now.

Problem is that it only works when the AC is on and in the heating mode the AC (heat pump) has to run additional time.

Better to just have solar hot water panels. I turned off the electric connection to the hot water tank on 1 April and will turn it on again in November. Zero power except for a very small recirc pump.
russ

The water heater connection is available from some AC models now.

Problem is that it only works when the AC is on and in the heating mode the AC (heat pump) has to run additional time.

Better to just have solar hot water panels. I turned off the electric connection to the hot water tank on 1 April and will turn it on again in November. Zero power except for a very small recirc pump.
MD

Same could be said for a refrigerator too, yet no one does it for the same reason Jean explained…
MD

Same could be said for a refrigerator too, yet no one does it for the same reason Jean explained…
http://jean.posterous.com Jean

Recovering ‘waste’ heat from an air conditioning unit would decrease its efficiency, make the unit under-perform when most needed and eventually require more energy to compensate for the losses than recovered.

This is another one of these greats ideas that recover energy by wasting more energy than recovered.
http://jean.posterous.com Jean

Recovering ‘waste’ heat from an air conditioning unit would decrease its efficiency, make the unit under-perform when most needed and eventually require more energy to compensate for the losses than recovered.

This is another one of these greats ideas that recover energy by wasting more energy than recovered.