On Sep 1, 5:51*pm, Mark wrote:
On Aug 31, 1:32*pm, Mac Cool wrote:

I'm in North Carolina so the weather is relatively mild. I would like to
switch to a heat pump. According tohttp://hes.lbl.gov/hes/about.html, I
could conservatively save about $1600/year on heating alone. I was as
thorough as possible when completing the survey. Last year my hvac guy, a
friend of the family, told me I wouldn't recoup the cost of replacing the
propane but I'm spending thousands each winter on propane. My propane
company has kept the price right at the break even point with electric, or
a little higher when it gets cold. The central unit is 7-8 years old,
propane heat/electric ac.

I'm going to sit down and discuss this with him next week. What are my
concerns and what questions should I ask?

it ALL epends on how much you have to pay for electricity. *Most
utilities have different rate tiers depending *if you have electric
heat or if you have time of day or peak demand metering.

Your first step is to get all this rate info from your electric
company.

Mark


thats all good advice... however the OP said that the natural gas is
priced on par with the electric in his arrea...whatever that means....
therm per dollar maybe.

if thats the case, with a heat pump you get 2x or more therms per
killowatt compared to electric resistance heat.. its
a leveraged deal.. the heat pump is almost always more efficent than
propane, not always cheaper than natural gas in the pipeline
though...but usually it is by a little at least.


My personal prime consideration since ive been in that side of the
business so long is how long do these systems last and what do repairs
cost.... its not at all uncommon to be billed several thousand dollars
for a repair.. my estimate, a heat pump owner can expect one of those
at 7 to 10 years and a few 300 dollar repairs in the meantime.... then
total replacement at 10 years... 20 would be a miracle system...and
that occurs but not often. 10 its usually toast.

***

I advise people to buy multile small seer 14 systems, air to air heat
pumps or electric cool/ gas heat ... zone the house so you only run
one at time...and use programmable stats... insulate well, use matress
warmers. that will be cheap to intall and cheap enough to operate.

For much larger systems the various flavors of geo thermal or cooling
tower/ heat sink applications are a very good deal especially when one
side of the building is in heat mode and the sunny south side is in
cool mode... networked water source heat pumps are a small miracle in
those cases.

If you oversize them to reduce compressor and fan run times they will
even last a while.




Phil scott