Cohousing-L Mailing List: Re: Heating systems

[David Hungerford (dghungerford]

NANCY WIGHT WROTE:
>1) If we install electric geothermal heat pumps, we will not be having gas
>piped to our site, which means we have to use electricity (where solar is
>not feasible) for heating water.  Given that gas is much cheaper than
>electricity, I'm wondering if we will *really* see an overall energy
>savings.

That all depends on how much hot water you use.  Yes, electric water
heating is very inefficient, and thus expensive.  I think that even if you
ran the gas lines just for hot water (and cooking, and clothes drying), you
still might be better off with the heat pump, especially if you get some
sort of rebate.

>2) I'm worried about the "extreme weather", which we have a lot of.  Would
>we also have to have a furnace (and air-conditioning system) for backup?

These units usually have electric resistance backup for those really cold
times.  But, are you considering fireplaces (or glass front stoves) as
decorative options.  They could serve as backup in extreme weather.  The
kind of cold snaps in which you lose electric lines shut down everything,
even gas heat (no fans).  As far as AC goes, you've jumped into my
dissertation topic.  The short question is "Is is okay to be a little warm
for a few hours per day a couple of weeks per year?"  Also, if your houses
are built well, that is, cross-ventilation, good insulation and windows,
maybe radiant barriers in the attic and on West walls, you can keep the
heat out in the summer, and basically won't need much cooling. Good Luck.

David Hungerford
Muir Commons