On Sunday, October 27, 2019 at 8:21:09 PM UTC-4, Commander Kinsey wrote:
On Wed, 23 Oct 2019 01:47:41 +0100, trader_4 wrote:

On Tuesday, October 22, 2019 at 8:32:32 PM UTC-4, Commander Kinsey wrote:
On Tue, 22 Oct 2019 08:29:13 +0100, alan_m wrote:

On 22/10/2019 07:29, Andy Bennet wrote:
On 21/10/2019 20:20, Commander Kinsey wrote:
Why can't I find a heat pump with a good SEER rating? The USA has a
law stating 13 minimum. Yet here in the UK, I looked at Panasonic and
they're all 7 to 11!

Its a longitude thing. High ratings are only achieved between about 70
and 120 degrees west.
A bit like music power really.

I'll bet that in the USA they may not be quoting the spec for heating,
just cooling

The USA has snowy parts does it not? Have they not realised you can reverse those AC units?

Sure, we have heat pump systems here. But not in the really snowy parts
though, because it gets too cold and the heat pump systems don't perform
well,

How cold? Aren't they as good as freezers, which get to -20C or less domestically, and commercial huge ones way lower.


As others have pointed out, the systems actually installed here start
to have issues when the temperature falls below freezing. If you're in
an environment where that doesn't happen much, then they can still be
fine. If you're where it typically goes below freezing for much of
the winter and can stay there or at 10 to 20F for days, then they suck.
Two problems. One is the COP declines at lower temperatures, so just
when you need the heat the most, that's when the capacity of the system
to turn electric into heat drops. When you're using it the most,
it's efficiency isn't the best. Second is that they are sized for
a balance of AC and heat. Here in the NY area, the heat system is
typically about 2x the capacity of the AC. So, you'd have to put in
a whopper of a heat pump and then that wouldn't be close to optimum
for cooling. The above results in long recovery times, which is a
pain. You can't set it back at night, it would take too long to recover.
If you have it set back while on a trip or something, it takes a long
time to recover, so you have a cold house. The above lead to aux electric
heat kicking in, which blows out the electric bill.

Like I said, I've only heard about a couple in these parts and those
were geothermal. How all that relates to a freezer, I have no idea.
I've never had one set lower than 0F. And how efficient they are
versus a heat pump for a whole house, IDK. A freezer is very small,
it could be 2x difference in efficiency at 0F than 25F and the
resulting difference in electric would still be small. Say we know
a freezer costs $150 a year to run at 0F. Do we know that it wouldn't cost
$50 a year to run at 25F?







other solutions, eg nat gas or oil are used. And I don't mean
super cold places either. In the NYC area, for example, I've never
encountered a heat pump system. There are a very small, insignificant
number, but AFAIK, only ones using geothermal, not air ones.
They are common in the southern parts of the country.