[Strawbale] Low-Cost Solar Assisted Heat Pump System littlehouses cross post

[Speireag Alden]

On 2007, Nov 28, at 14:06, Michele O'Malley wrote:

> Thanks for the advise. I know the winters are brutal, it can get as  
> low as -40F at night. Most people use propane I guess but I was  
> really hoping to get away from the fossil fuels. Any suggestions  
> for eco-friendly but affordable back up heat?

     Wood?

     Electricity, if you have the option of buying green watts.

     The key to making it affordable, no matter what it is, is to  
build the house such that you don't need much heat.  Passive solar is  
a must.  Some thermal storage, passive or active, is a must, to carry  
you through the cloudy days.  Solar thermal collection is your  
quickest payback after reducing usage.

> I have heard that radiant floors are expensive and I really don't  
> have a lot of money.

     They don't have to be.  My entire radiant floor system,  
excluding the heater itself, was around $1000, including a brass  
pump, lots of fittings, and lots of pipe.  It used to be hooked to a  
propane demand heater, but right now it's on an electric tank heater  
(no vent, so I can move it as I put on an addition).

     My system has one zone, and works off a timer switch.  Simple.

> What is the consensous with eco minded people about using  
> electricity as back-up heat vs natural gas/propane.

     It's fine, if it's minimal, or if they're green watts.

> Even now in my W. Pa home I tend to use an electric space heater  
> (that looks like a woodstove) to take the chill off the main living  
> space and not have the natural gas kick on. Any opinions on which  
> is best both economically and environmentally?
> I guess it is unrealistic to expect any solar design, passive or  
> active to keep a house comfortable in that climate during the winter.

     It is not unrealistic.  But it takes research, because most  
builders don't know a thing about this kind of design.  You may not  
be able to get every last bit of your heat in that climate, but you  
can probably get 80-90% without too much difficulty, and the generate  
the last bits during the darkest, coldest weather by minimal use of  
backup.

-Speireag.