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New technology for residential; is it worth it?

20K views 79 replies 6 participants last post by  RoBoTeq 
The problem with 23 SEER air to air versus ground source heat pumps is in the heating mode. While ground source heat pumps stay fairly stable in capacity, standard air to air heat pumps lose capacity as the OD temps drop, exactly when more capacity is needed.

Tha Acadia heat pump is the only exception to this factor right now, but it is only rated at 14 SEER in the cooling mode.
Well the way I understand it, ground source heat pumps can be competitive is to use a hybrid system. That is in conjunction with a small cooling tower in the South and a small hot water heater in the North to cover about half the capacity and then you will only need to dig half the wells and you use your HP for 70 to 80 % of your needs and the back up only in extreme conditions.
 
We're discussing the benefits of higher efficiency technology in residential applications.
Yeah but it works for buildings why wouldn't it work for say a mansion. Only a mansion would look at getting s system like that anyhow. I know someone who has a small chiller in their basement. Naturaly for a mansion but still there are such things.
 
A rough rule of thumb in my area is about 200 ft of pipe per ton of ac for a ground water system. So you are talking about 1000 ft of pipe for a 5 ton and unless you have lots of available land you go with a series of vertical wells.

Now if you supplement the ground water system with a real small cooling tower that would save you on installation because you could reduce your drilling and laying pipe in half and only when it is real hot do you even need to use the cooling tower. That is what my dealer is telling me. Just wanted to pass this along. It won't work up North because there you have a problem in winter more than summer.
 
I have to agree with there being no reason to have a furnace that's less then 90% efficient, even 93%. The argument that more southern areas can't justify the cost for a condensing furnace is a moot point with the heat pumps that are available.

I also agree that the psc motor will quickly become a dinosaur that will be replaced with lower efficiency DC motors, whether variable speed controlled or not. These DC motors can easily be operated off of the amount of power produced by relatively cost effective solar voltaic panels. Just think, with solar powered blower and controls on a gas furnace, there would be no fear of a power outage.
I have to argue the point. 90% + furnaces don't cost that much more for new construction because you don't have to run the double wall vent stack up to the roof with a 90+ unit. Plus with the savings on fuel you should be able to recover within 2 or 3 years and less than a year if your going from a basement up two floors and a attic above. Now a heat pump is probably the cheapest option on new construction overall the way I see it in the South.
 
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