We are just now in the midst of an energy retrofit for our house in Seattle
that includes replacing the 1973 gas conversion burner on the original 1950
boiler (50% efficient) and 1994 electric hot water tank with a new
condensing boiler and indirect-fired hot water tank (95% efficient), as
well as air sealing and adding R-60 insulation to the attic, and new
Energy-Star refrigerators for us and our tenant in the mother-in-law
apartment. Through a City of Seattle program, Community Power Works, we
were able to get a low-interest loan to do the work. The loan will be
repaid on our City Light electric bill. The savings we'll get will easily
pay for the loan now, and we will be better off as energy rates increase
over the life of the loan. If we sell the house, the loan can stay with the
house. This gets around the whole "simple payback" issue. This is the way
it's done in Germany and Austria.
In my practice ground-source heat pumps rarely have made sense in the past,
and air-source heat pumps are even better now than they were (higher COPs)
and are less expensive these days. In fact, I have used the logic that my
clients will be better off adding Passivhaus-levels of insulation and
higher performance windows (cost-neutral, paid for by giving up the
ground-source heat pump) and reducing demand to the point that heating can
be taken care of by simple electric resistance heating with perhaps an
air-tight stove for the 8-10 coldest days of the year. Way simpler
technically, and less maintenance. I know that strategy works up to about
8,000 Heating Degree Days--I used it on a cabin in the Cascades.
Rob in Seattle
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