[Greenbuilding] Ductless Heat Pump Performance - November 2011

Paul Eldridge paul.eldridge at ns.sympatico.ca
Sat Dec 3 19:10:11 PST 2011

nick pine nick at early.com writes:

>Paul Eldridge<paul.eldridge at ns.sympatico.ca  <http://lists.bioenergylists.org/mailman/listinfo/greenbuilding_lists.bioenergylists.org>>  writes:
>>/... virtually all of our space heating needs are satisfied by two ductless
/>>/heat pumps and our DHW is heated electrically... our consumption for
/>>November can be viewed at:
>  http://i362.photobucket.com/albums/oo69/HereinHalifax/HP-Nov2011.jpg
>Your heat pumps made 964.4 kWh of space heat with 13.1x30d = 393 kWh at a
>2.45 COP?

With respect to November's COP, we spent several days painting in 
preparation for the holidays, during which time we had windows open to 
air out the place.  Our heat loss calculations do not take into account 
these additional space heating demands, so our actual COP would be 
higher than what is stated here (how much higher, I do not know).

 >>Our goal this year is to get our total household consumption below the
 >>10,000 kWh mark...

 >Less than 10K kWh in an average year seems easy with the help of some 
 >siding :-)

I should make clear that this goal includes all energy demands, i.e., 
space heating and cooling, domestic hot water, major appliances and all 
plug loads including those of my home office.  One of our largest 
demands is our dehumidifier which runs seemingly non-stop four months of 
the year.

Also, as noted before, our solar options are limited.  Our home faces 
east-west, the roof line is punctuated by multiple dormers and the south 
side is heavily shaded by a steep rock face and stand of trees.  Even if 
this were not the case, I'm not inclined to alter the appearance of our 
home in any material way, particularly when our space heating costs are 
comparatively modest and the electricity that we consume is 100 per cent 
renewable.  I'm content to keep things as they are.


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