[Greenbuilding] Geothermal (ground source) Heat Pump question

[Reuben Deumling]

I'm imagining that heating that water from 54F to, say, 160F(?) will take
electricity. Proponents of these systems seem to minimize this need,
pointing to the *efficiency* of such a device. Then they point to savings of
such systems over those they presumably are replacing. While this may be
true, we generally don't know much about the previous system's
characteristics--and there are surely plenty of systems out there that are
poorly designed or operated. I haven't come away reassured that this
technology is as ingenious as proclaimed.

Putting the question another way, if I use 500 therms to heat my house with
natural gas over a winter, and then switch to a GSHP, approximately how many
kWh might this unit require to match the thermal criteria formerly met by
the natural gas heating system?

Thanks.

Reuben Deumling

On Jan 10, 2008 2:47 PM, Ted Inoue <tedinoue at gmail.com> wrote:

> If they're saying that it won't use any electricity in the winter, they
> haven't a clue. If they don't have some people involved who know what
> they're talking about, this is going to be a disaster.


Before (if) it gets built, they're sure to find such people. In the
meantime, though, it is being trotted out to folks who like the sound of
renewables heating their houses, but most of whom aren't asking tough
questions.