On 27 November 2014 at 08:13, Geoff Oltmans <oltmansg at gmail.com> wrote:
On Nov 26, 2014, at 3:04 PM, Chuck Guzis wrote:
Electrical resistive heating for household
hea[t]ing in the US is being discouraged. There are government incentives to convert to
much more efficient heat pump technology--with the side benefit of air conditioning in the
summer. I do have "emergency" resistive heating elements in my air
handler--they're connected to two 40A/240V circuits.
Yeah, and heat pumps work great for heat until there is no heat in the outside air from
which to extract. With my current (albeit aging) system, that temperature is around 28F,
then it's on to the heat strips.
Just get a newer heat pump :-)
They're getting better year by year. The technology improves rapidly.
The one I have installed in my living room starts out at more than
4-to-1 efficiency, 4kW heat for 1kW of electricity. It doesn't get
down to 1-to-1 until -20C, that's about -4F I think. And it doesn't
really get that cold in my town. The heat pump is barely ticking over
to keep the larger part of the house warm most of the time. I don't
need any additional heating to keep the whole second floor warm if I
wish to (just open the doors. The heat pump, although not a big
model, can take it. But house insulation is also very good in Norway,
and that's probably the best first step one should look at,
everywhere).
The newest models though (three to four years newer than mine) are
closer to 5-to-1, and they are able to extract heat from outside air
until the temperature drops down to -30C (-22F). It's really
impressive. If someone had told me ten years ago that you can extract
useful heat from air all the way down to -30C, for less energy than
you put in, I would have rejected the notion.
Most of these heat pumps are Japanese.. Panasonic, Mitsubishi etc.
(there's also at least one Korean, from Samsung. I have no knowledge
about it). Those Japanese heat pumps are called 'Nordic' models.. the
funny thing is that I can't find them in Japan! Only "old style"
combination heater/AC systems. Now there's a place where some energy
efficiency is loudly called for. Seems their best goods are only for
export, at least for that category. Anyway, that heat pump did wonders
for the electricity bill, even though I used to burn (free) wood in a
wood stove nearly every day all winter in the past. Not anymore, and I
still use much less electricity.
(And I just noticed that the price of heat pumps seems to have dropped
by half compared to some years ago.)
-Tor