"Paul M. Eldridge" wrote in message
...
Hi Mike,

There are 100,000 BTUs per therm of natural gas, or the equivalent of
29.3 kWh of electric heat.

A mid efficiency furnace operating at 80 per cent efficiency will
provide you with 23.4 kWh of heat per therm (the other 5.9 kWh being
lost up the chimney). A high efficiency furnace with a 90 per cent
efficiency rating would give you 26.4 kWh/therm and at the very top
end of the scale you might achieve upwards of 28 kWh/therm.

It looks like BGE is currently charging residential customers $1.30
per therm (commodity and delivery prices combined). At 80 per cent
conversion efficiency, each kWh of gas heat costs you roughly 5.5
cents and at 90 per cent efficiency, that cost falls to 4.9 cents per
kWh(e).

I believe BGE's winter electric rate now stands at 12.73 cents per
kWh. A high efficiency heat pump with a seasonal COP of between 2.5
and 3.0 (not an unreasonable number given your relatively moderate
winters), would produce heat in the range of 4.2 to 5.1 cents per
kWh(e).

One of the Fujitsu ductless heat pumps has a HSPF of 11.0, which puts
its seasonal COP at just over 3.2. That effectively reduces the cost
of electric heat to just 3.9 cents per kWh(e), or some twenty per cent
below that of a high efficiency gas furnace operating at 90 per cent
efficiency.

One of the nice things about a ductless heat pump is that you can
simply leave your electric baseboard heaters in place, so there's no
need to rip them out, re-plaster your walls and repaint your rooms.
This also provides you with backup emergency heat should your heat
pump require servicing.

Cheers,
Paul

On Sun, 28 Jan 2007 01:22:31 GMT, "Mike" wrote:

I've got a gas stove and water heater. How can I convert BTU/therms to kw
so I can compare costs?

Paul, another poster stated the cost on NG is going up, and I assume, might
even surpass electricso the HP is evenn more appealing. How does it cool in
the rooms in the summer?