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Keith: Check out off-grid model of the two built on the Toronto Healthy House Project.<BR>
Carmine<BR>
<A href="http://www.gfxtechnology.com">www.gfxtechnology.com</A><BR> <BR>
> Date: Tue, 7 Dec 2010 21:52:33 -0500<BR>> From: keith@earthsunenergy.com<BR>> To: greenbuilding@lists.bioenergylists.org<BR>> Subject: Re: [Greenbuilding] off-grid home<BR>> <BR>> On 12/7/2010 12:05 PM, Chris Koehn wrote:<BR>> > I've been asked to general contract a home on one of the B.C. southern Gulf islands without grid power. This is an architect designed, 1,600 s.f. home and while I have little influence with the over-all design, the owners have expressed desire to pursue some solar (evacuated tube and possibly PV) and have settled on wood as the primary heat source via a cook stove and separate fireplace.<BR>> > I am keen to find someone to help design an H/V system that meets B.C. code requirements, provides a modicum of comfort specific to the design of this home, consumes very little electricity and a minimum of propane, and can keep the home from freezing up when unoccupied. Anyone interested please contact me off-list.<BR>> <BR>> I've been working on an off-grid home -- I was fairly involved in the <BR>> energy side of the design from the beginning, it's a bit over 2000 sf. <BR>> 6 kW PV system, 80k kWh battery, geothermal heating. I'm not completely <BR>> happy with it -- I went with the SMA Sunny Boy/Sunny Island combo that <BR>> has some good and bad points, and we're just about to install a 14 kW <BR>> backup generator which is necessary to equalize the batteries and <BR>> address heavy loading periods in the absence of concomitant sunshine (I <BR>> think if we'd installed the generator in the beginning, a few months <BR>> ago, everyone would have been much happier, even though it will <BR>> probably get very little use). The PV system (and probably battery) <BR>> should have been bigger (!), because the house is all tricked out with <BR>> modernistical stuff like dishwashers, clothes dryers etc. And an <BR>> elevator... There's no wood or other biofuel backup.<BR>> <BR>> Anyway, I'd recommend mini-split heat pumps. They can be almost as <BR>> efficient as geothermal (26 SEER!), but they are completely zoned by <BR>> nature (you don't have to turn on the entire house). Unfortunately, all <BR>> the most efficient ones hang on a wall and have a noticeable visual <BR>> impact. The Fujitsu RLQ series I like will pretty well heat down to 5F <BR>> give or take, so they'll certainly keep the pipes from freezing. Of <BR>> course, insulate the house like CRAZY, and put in GREAT windows. Be <BR>> uncompromising about those points, since YOU are going to hang if it <BR>> doesn't work in the end. You can get mini-splits in multi-head <BR>> configurations (Fujitsu now has one that goes all the way up to 8 <BR>> indoor units), some of which give central control capability while <BR>> still maintaining zonability, but the efficiency drops quickly even <BR>> with just a second head (i.e. more like 16-17 SEER). Properly used, of <BR>> course, a zoned 16 SEER system might be MUCH more efficient than an <BR>> whole-house 16 SEER system (if you're willing to define efficiency in <BR>> relation to comfort).<BR>> <BR>> You can contact me off-list if you want consulting services, though I'm <BR>> uncertain how available I am right now. Good luck on your project.<BR>> <BR>> Warmly, Keith<BR>> <BR>> _______________________________________________<BR>> Greenbuilding mailing list<BR>> to Send a Message to the list, use the email address<BR>> Greenbuilding@bioenergylists.org<BR>> <BR>> to UNSUBSCRIBE or Change your List Settings use the web page<BR>> http://lists.bioenergylists.org/mailman/listinfo/greenbuilding_lists.bioenergylists.org<BR> </body>
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