"Commander Kinsey" wrote in message
newsp.z91bk6w7wdg98l@glass...
On Tue, 22 Oct 2019 00:44:45 +0100, Rod Speed
wrote:



"Commander Kinsey" wrote in message
newsp.z908xwllwdg98l@glass...
On Mon, 21 Oct 2019 23:23:19 +0100, alan_m
wrote:

On 21/10/2019 20:50, A noiseless patient Spider wrote:
On 10/21/2019 3:20 PM, 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!

It's because we use 120/240 volt 60 Hz two-phase. Your single-phase
50
Hz is less efficient.

https://www.energystar.gov/products/...rce_heat_pumps

Doesn't it also depend on if it's been optimised for air conditioning
to
cool air in the summer rather than being optimised for heating during
the winter in climates such as the UK?

Is that necessary?

For the best SEER rating, yep.

If it's reversible, isn't it just that?

Nope. The problem with using them for heating
in a climate like yours is that the outside heat
collector does ice up and you need a much
bigger outside heat absorber to get the best
SEER rating for winter heating.

Argh, so I really need to find data for the heating and the cooling cycle.

You don't get that effect with summer aircons.

Obviously it will be less efficient when it's pushing heat through a
larger gradient (which will happen in heating mode), but that can't be
helped.

It can actually with two stage designs.

Two seperate circuits? Two condensers etc?

Yep, to help with the much bigger temperature
difference seen with winter heating.

Consider also it appears from many of the examples I've seen honesty
doesn't seem to be part of USA advertising.

Don't they have a government body to check they're honest?

Nope.

And it ain't just the USA - almost everything you buy with a rating is a
lie.

Not a lie so much as its hard to come up with a single digit number
that really does rank the devices properly, even with something as
simple as a fridge or freezer, let alone a heat pump.

Bull****. A camera makes a certain number of pixels.

That's not a rating, that's a spec.

A battery has a certain number of amp hours.

Again, that's not a rating, that's a spec.

For example, I bought a "Probat" (****ty make) car battery, and an Exide
(good make) car battery. They were both rated at 45 Ah.

Again, that's not a rating, that's a spec.

I charged them both fully. Then I connected each to a car headlamp bulb,
drawing about 4 amps. I measured the current over time and worked out the
real Ah. The Exide was almost spot on, about 43 Ah. The Probat was 32
Ah. I got a partial refund when I yelled at the seller.

Sure, but that's not a rating, that's a spec.

Cameras have the same problem. My Fuji camera claims 10MP. But it's
very easy to determine it's actually about 2.5MP.

That's a different problem, optical and physical MPs.

Take a picture at full resolution in favourable lighting. Load it into
Photoshop and reduce the size to 2.5MP. Save it. Load it again, then
enlarge back to 10MP. Clearly this image now only has 2.5MP of data.
Compare this image to the original from the camera. They're identical!
So the camera was giving out no more data than a 2.5MP file. They lied.

Nope, you don't understand the difference
between optical and physical MPs.

Cameras with less megapixels than they say,

That's not a rating, that's a lie about the specs.

Rating, specs, same thing.

Nope.

It's a number defining the capabilities of the device.

Ratings arent, specs are.

batteries with less capacity than they say, etc.

Ditto. But that doesn't happen with the best of them like
the Panasonic Li ion batterys or the apple iphone batterys

Iphone! BUAHAHAAH!!! Everyone I know with an Iphone is constantly
moaning it went flat.

I don't and my mates Samsung Galaxy S10 goes flat
a lot quicker when we are talking to each other for
hours during the garage sale run and after that.

My £13 phone lasts for WEEKS between charges.

But doesn't do anything like what a smartphone does.

What Apple did wrong was the same mistake Clive Sinclair made - making
things smaller to the cost of everything else.

Not with ipads they didn't.

No room for enough battery.

Same with all smartphones.

My phone uses two 18650 Li Ion batteries - same as a cycle lamp - total is
4.2V 6Ah.

And does **** all that a smartphone does.

Easy to get replacements too. Oh and you don't need special tools to open
the battery cover.

And does **** all that a smartphone does.

And the phone doesn't deliberately disable itself if an unauthorised
person opens it.

iphones don't do that.

Its more complicated with smartphone talk time which
varys quite a bit depending on whether you are in a
strong signal area or a weak one where the phone
need to transmit more power to be seen by the base.

Yes, a phone can't guarantee battery life, but the battery itself can
state a very precise Ah.

And that's a spec, not a rating.

They could also simply quote the measurement along with the conditions
required.

They do.

Eg. this car will get 50mpg if you drive on a motorway at a constant
70mph.

And that still doesn't tell you what result you
will actually get with particular air temps etc.

Or this phone will allow you to talk for 3 hours if your signal strength
is 90%.

There is no signal strength you can do that with.

Every time I buy something like that, I test it thoroughly, then get a
partial refund :-)

You don't with Panasonic Li ion batterys.

Agreed - they don't lie. I have 6 of those 18650 Panasonics here. 3Ah on
the label, 3Ah on my test. Even Samsung only get 80% of their rating.

Its not a rating, it's a spec.

But try Chinese **** and you get 20%!