[Greenbuilding] Subject: heat pump advice

[Nick Pine]

Kevin Zippel <zippelk at yahoo.com> wrote:

>... I have a ~2500sf farmhouse in zone 5b, Finger Lakes region New York. 
>Our house has average insulation, except the attic which we just bumped up 
>to R70.  The house had ducted air heating via a propane furnace, which we 
>promptly shut off and went with woodstove heat.  The house is in a 
>floodplain and there is a free-flowing artesian well on the side of the 
>house.  Without a pump, the water comes out at 5 gal in ~6.5min, or ~3/4 
>gpm, or ~45 gph.  Would it be possible/reasonable to run that through a 
>water-to-air heat pump (likely with supplemental pumping from the well) and 
>run the air directly into my existing ductwork?

Cooling 375 pounds per hour of 45 F water to 35 would be 3750 Btu/h, but how 
about solar heating with a COP of 1000 or more, vs 3 for a heat pump?

Binghamton gets 610 Btu/h-ft^2 on a south wall on an average 26.5 F December 
day, more than Rochester, with 560, where I designed a system to solar heat 
a 1200 ft^2 addition with R30 walls with a 240 ft^2 twinwall polycarbonate 
sunspace wall and 144 ft^2 of single air heater glazing inside that with 64 
ft of fin-tube pipe near the top to heat a 1000 gallon STSS tank in the 
basement, in a kind of thermal cogeneration. If all goes well, on an average 
day, warm sunspace air will heat 2400 pounds of water in 4" PVC pipes under 
a foil-covered cathedral ceiling, and a slow ceiling fan and a room temp 
thermostat and an occupancy sensor will keep the room 70 F. The water will 
cool to about 60 F by dawn, with a 50 F night setback. On a cloudy day, we 
will pump some tank water up through the ceiling pipes, and the tank will 
also heat DHW with a pressurized copper coil. My TMY2 simulation shows 100% 
solar space heating in an average year, with a min tank temp of 91 F in 
mid-December.

Nick