On 5/7/2018 12:15 PM, Jimmy Wilkinson Knife wrote:
On Mon, 07 May 2018 15:36:47 +0100, Unquestionably Confused
wrote:

On 5/7/2018 9:08 AM, Jimmy Wilkinson Knife wrote:
On Mon, 07 May 2018 15:05:56 +0100,
wrote:

On Monday, May 7, 2018 at 9:44:59 AM UTC-4, Jimmy Wilkinson Knife
wrote:
On Mon, 07 May 2018 14:36:24 +0100, KenK
wrote:


[snip]

Why on earth could an AC unit not run backwards?* You just reverse
the pump.* Every one I've seen in the UK (commercial and home) has
been able to do this.* The controller usually has settings for
heating, cooling, or automatic.* On automatic you can simply set a
range (say 18 - 22C) and if it goes over, it cools, if it goes under,
it heats.

What you're describing is what is referred to a split unit system or
inverter.* After screwing around with a through the wall A/C unit which
was noisier than all get out in the size needed to cool the addition, I
finally got smart and picked up a split system (air handler inside,
compressor/inverter outside).* What a difference. Very quiet (hard to
tell it's running, actually), and much cheaper than our old A/C unit.
And, as you say, when heat is needed, the system reverses itself and
heats the interior drawing heat from outside even when it's in the 20F
degree range outside.

I wasn't aware they still made the one way systems.* I know of several
commercial and domestic places around here in the UK who have had AC
units fitted (and they only wanted to cool the room down), and they're
all reversible.

Personally, I have never seen a window type inverter system such as you
describe, only the split systems. Doesn't mean they aren't out there on
this side of the pond, just that I've not seen them and I was looking
for any suitable alternatives to the window/thru wall units two years
ago when I went to the current split.