A useable AS heat pump?

<https://www.theguardian.com/environment/2022/jan/07/new-heat-pump-could-ease-uk-shift-to-low-carbon-homes-say-developers>
As it's European - and I'd guess that the Swedes know a bit about heating -
this might just work.

AFAIK with heat pumps, higher temperature output means lower coefficient of
performance?

2022-01-08 15:27:31 UTC

AFAIK with heat pumps, higher temperature output means lower coefficient
of performance?

hmmmmm

https://purethermal.co.uk/high-temperarure-heat-pumps/

there is mention of two stage heat pumps so that looks like two heat
pumps in series so you have say 5 degree air source to say 40 degree
water which is then fed into the 2nd heat pump which then outputs 75
degree water, so each stage is 35 degrees delta T, thus hopefully
improving the COP?

Or it could simply be a resistive electric heater to warm up the
incoming air or to "top up" the temperature of the output water?

Martin Brown

2022-01-08 16:43:44 UTC

They have homes that are incredibly well insulated though to begin with.

Post by Andy Burns
AFAIK with heat pumps, higher temperature output means lower
coefficient of performance?

There is no free lunch. The higher the temperature difference required
the lower the overall efficiency/coefficient of performance becomes.

That is why heat pump designs typically go for large area low
temperature underfloor heating and/or huge lower temperature radiators.

Post by SH
hmmmmm
https://purethermal.co.uk/high-temperarure-heat-pumps/
there is mention of two stage heat pumps so that looks like two heat
pumps in series so you have say 5 degree air source to say 40 degree
water which is then fed into the 2nd heat pump which then outputs 75
degree water, so each stage is 35 degrees delta T, thus hopefully
improving the COP?

Twice as much heat pump hardware to go wrong and twice as much
electricity used compared to a single heat pump.

The other big snag is that you have no heating at all if the electricity
goes off as it tends to do round here in mid-winter storms. A situation
made much worse recently by that pissup in a brewery Northern Powergrid.
At least NEDL used to do some preventative maintenance in summer.

Post by SH
Or it could simply be a resistive electric heater to warm up the
incoming air or to "top up" the temperature of the output water?

That would be madness. Hydrogen fuel cell combined heat and power is a
more attractive proposition if you can get enough hydrogen.

--
Regards,
Martin Brown

Andrew

2022-01-17 17:29:50 UTC

They have homes that are incredibly well insulated though to begin with.

Like Canada, they don't have the gulf stream to keep them warm. If we
had winters like theirs, our houses would be better insulated, but
with mild winters people would rather spend excess income on
holidaying in the sun and luxury living. Plus the hideous tendancy
to have 'exposed brick and/or stone' inside 'character' properties.

sid

2022-01-08 17:37:57 UTC

<https://www.theguardian.com/environment/2022/jan/07/new-heat-pump-

could-ease-uk-shift-to-low-carbon-homes-say-developers>

As it's European - and I'd guess that the Swedes know a bit about heating -
this might just work.

AFAIK with heat pumps, higher temperature output means lower
coefficient of performance?

hmmmmm
https://purethermal.co.uk/high-temperarure-heat-pumps/
there is mention of two stage heat pumps so that looks like two heat
pumps in series so you have say 5 degree air source to say 40 degree
water which is then fed into the 2nd heat pump which then outputs 75
degree water, so each stage is 35 degrees delta T, thus hopefully
improving the COP?
Or it could simply be a resistive electric heater to warm up the
incoming air or to "top up" the temperature of the output water?

Mine works quite well, with domestic water set at 44C.

Martin Brown

2022-01-09 10:44:07 UTC

<https://www.theguardian.com/environment/2022/jan/07/new-heat-pump-

could-ease-uk-shift-to-low-carbon-homes-say-developers>

As it's European - and I'd guess that the Swedes know a bit about heating -
this might just work.

AFAIK with heat pumps, higher temperature output means lower
coefficient of performance?

hmmmmm
https://purethermal.co.uk/high-temperarure-heat-pumps/
there is mention of two stage heat pumps so that looks like two heat
pumps in series so you have say 5 degree air source to say 40 degree
water which is then fed into the 2nd heat pump which then outputs 75
degree water, so each stage is 35 degrees delta T, thus hopefully
improving the COP?
Or it could simply be a resistive electric heater to warm up the
incoming air or to "top up" the temperature of the output water?

Mine works quite well, with domestic water set at 44C.

Perfect temperature for Legionella to thrive in the hot water tank.

https://en.wikipedia.org/wiki/Legionnaires%27_disease#Prevention

--
Regards,
Martin Brown

Steve Walker

2022-01-09 17:37:53 UTC

<https://www.theguardian.com/environment/2022/jan/07/new-heat-pump-

could-ease-uk-shift-to-low-carbon-homes-say-developers>

As it's European - and I'd guess that the Swedes know a bit about heating -
this might just work.

AFAIK with heat pumps, higher temperature output means lower
coefficient of performance?

hmmmmm
https://purethermal.co.uk/high-temperarure-heat-pumps/
there is mention of two stage heat pumps so that looks like two heat
pumps in series so you have say 5 degree air source to say 40 degree
water which is then fed into the 2nd heat pump which then outputs 75
degree water, so each stage is 35 degrees delta T, thus hopefully
improving the COP?
Or it could simply be a resistive electric heater to warm up the
incoming air or to "top up" the temperature of the output water?

Mine works quite well, with domestic water set at 44C.

Perfect temperature for Legionella to thrive in the hot water tank.
https://en.wikipedia.org/wiki/Legionnaires%27_disease#Prevention

I have a vague recollection of reading somewhere that low temperature
tanks, fed from heat-pumps, are supposed to be heated to a higher
temperature every so often (a week?) to prevent legionella problems.

The Natural Philosopher

2022-01-09 17:49:25 UTC

Post by Steve Walker

<https://www.theguardian.com/environment/2022/jan/07/new-heat-pump-

could-ease-uk-shift-to-low-carbon-homes-say-developers>

As it's European - and I'd guess that the Swedes know a bit about heating -
this might just work.

AFAIK with heat pumps, higher temperature output means lower
coefficient of performance?

hmmmmm
https://purethermal.co.uk/high-temperarure-heat-pumps/
there is mention of two stage heat pumps so that looks like two heat
pumps in series so you have say 5 degree air source to say 40 degree
water which is then fed into the 2nd heat pump which then outputs 75
degree water, so each stage is 35 degrees delta T, thus hopefully
improving the COP?
Or it could simply be a resistive electric heater to warm up the
incoming air or to "top up" the temperature of the output water?

Mine works quite well, with domestic water set at 44C.

Perfect temperature for Legionella to thrive in the hot water tank.
https://en.wikipedia.org/wiki/Legionnaires%27_disease#Prevention

yes.
60°C
Done with an immersion heater. In fact DHW is such a small part of
heating bills I think they leave it on all the time. Going from about
10°C to 40°C is over half the heating = the rest can be done direct

--
"In our post-modern world, climate science is not powerful because it is
true: it is true because it is powerful."

Lucas Bergkamp

Theo

2022-01-09 20:45:18 UTC

Post by The Natural Philosopher
yes.
60°C
Done with an immersion heater. In fact DHW is such a small part of
heating bills I think they leave it on all the time. Going from about
10°C to 40°C is over half the heating = the rest can be done direct

No, the immersion is usually brought in on a separate cycle. Most of them
have that as part of the controls, or the old school installs can have a
separate relay box and timer.

On ours there's a separate 'hot' stat - once the ASHP has got the tank up to
temperature (eg 55C) the 'hot' stat closes and the immersion (set to the
usual integral 60C stat) kicks in to bring it up to legionella-zapping
temperature. If the tank hasn't already got up to temps the legionella
immersion won't kick in, meaning you aren't running electric heat except for
that last 5C. Currently the timer is set to fire that topup immersion once
a week.

(there are tables that give you the frequency you should run it, from twice
a week to once every 2 weeks - if you don't use much hot water so the water
sits around, or someone in the house is immunologically compromised, you
should run it more often)

Theo

alan_m

2022-01-15 00:47:22 UTC

Post by Martin Brown
Perfect temperature for Legionella to thrive in the hot water tank.
https://en.wikipedia.org/wiki/Legionnaires%27_disease#Prevention

In a typical domestic environment is this a real problem? The chances
are that no water becomes stagnated and the water in the tank is being
replenished throughout the day, and every day, with chlorinated water
from the mains.

--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

Theo

2022-01-15 15:09:51 UTC

Post by alan_m

Post by Martin Brown
Perfect temperature for Legionella to thrive in the hot water tank.
https://en.wikipedia.org/wiki/Legionnaires%27_disease#Prevention

It depends. Probably not in most cases. But:

Some people don't use a lot of water, so the tank doesn't get much
replenishment. For example people who live alone, bathe once a week (or
have an electric shower) and only use a little hot water in sinks the rest
of the time.

Some people have weak immune systems (elderly, etc) and are more susceptible
to pathogens. Other people smoke, and so likewise.

Since an installer can't know whether those things will apply, either at
present or to future occupants, they need to put mitigations in place.
A simple immersion boost is not a big ask.

Theo

Andrew

2022-01-17 17:30:42 UTC

<https://www.theguardian.com/environment/2022/jan/07/new-heat-pump-

could-ease-uk-shift-to-low-carbon-homes-say-developers>

As it's European - and I'd guess that the Swedes know a bit about heating -
this might just work.

AFAIK with heat pumps, higher temperature output means lower
coefficient of performance?

hmmmmm
https://purethermal.co.uk/high-temperarure-heat-pumps/
there is mention of two stage heat pumps so that looks like two heat
pumps in series so you have say 5 degree air source to say 40 degree
water which is then fed into the 2nd heat pump which then outputs 75
degree water, so each stage is 35 degrees delta T, thus hopefully
improving the COP?
Or it could simply be a resistive electric heater to warm up the
incoming air or to "top up" the temperature of the output water?

Mine works quite well, with domestic water set at 44C.

Perfect temperature for Legionella to thrive in the hot water tank.
https://en.wikipedia.org/wiki/Legionnaires%27_disease#Prevention

Not if you have a copper tank. Copper is a wonderful biocide.

Robin

2022-01-08 15:49:17 UTC

AFAIK with heat pumps, higher temperature output means lower
coefficient of performance?

I remember enough heat engine theory to have a sneaking suspicion its a
bit more complicated than that and depends on the working fluid. But not
enough to give chapter and verse, sadly.

but limiting factor is still the ideal Carnot cycle where CoP goes down
as difference between input and output temperatures goes up?

COP=Khot/(Khot - Kcold)

--
Robin
reply-to address is (intended to be) valid

Brian Gaff (Sofa)

2022-01-09 08:34:12 UTC

Does this mean that your fridge is basically a hole in the ground so you can
make use of the heat extraction for the home grin.
Brian
--
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...
***@blueyonder.co.uk
Blind user, so no pictures please
Note this Signature is meaningless.!

AFAIK with heat pumps, higher temperature output means lower coefficient
of performance?

I remember enough heat engine theory to have a sneaking suspicion its a
bit more complicated than that and depends on the working fluid. But not
enough to give chapter and verse, sadly.

but limiting factor is still the ideal Carnot cycle where CoP goes down as
difference between input and output temperatures goes up?
COP=Khot/(Khot - Kcold)
--
Robin
reply-to address is (intended to be) valid

newshound

2022-01-09 10:31:28 UTC

Post by Brian Gaff (Sofa)
Does this mean that your fridge is basically a hole in the ground so you can
make use of the heat extraction for the home grin.
Brian

Well it is of course, except that all the cold that you pump into it
eventually leaks out into the house.

Tim+

2022-01-08 16:16:15 UTC

AFAIK with heat pumps, higher temperature output means lower coefficient of
performance?

Kinda telling that there’s no mention of COP anywhere in the info for this
heat pump. I guess they’re hoping that people won’t notice that it’s gonna
be even more expensive than gas heating or a “regular” ASHP until too late.

Tim

--
Please don't feed the trolls

Chris J Dixon

2022-01-08 16:54:12 UTC

AFAIK with heat pumps, higher temperature output means lower coefficient of
performance?

Kinda telling that theres no mention of COP anywhere in the info for this
heat pump. I guess theyre hoping that people wont notice that its gonna
be even more expensive than gas heating or a regular ASHP until too late.

There seem to be contradictory statements.

"The developers claim their product is not a one-size-fits-all
solution for everywhere in the country, but it could be the most
effective solution to low-carbon heating in rural and suburban
areas."

But then

'The high-temperature heat pump solution is innovative, simple
to install and could be the solution to help decarbonise homes in
the UK that are heated using traditional gas boiler,' said Mark
Anderson, the commercial and development director at Vattenfall
Heat UK."

Chris

--
Chris J Dixon Nottingham UK
***@cdixon.me.uk @ChrisJDixon1

Plant amazing Acers.

Andy Burns

2022-01-08 17:00:58 UTC

"The high-temperature heat pump solution is innovative, simple
to install and could be the solution to help decarbonise homes in
the UK that are heated using traditional gas boiler,' said Mark
Anderson, the commercial and development director at Vattenfall
Heat UK."

Can't see much on the Vattenfall website, plus it seems to hate firefox (or
adblockers) but the Feenstra site (with google translation from Dutch so beware
of hovercraft) seems to talk about a hybrid gas boiler + ASHP.

The Natural Philosopher

2022-01-08 18:13:26 UTC

Post by Tim+

AFAIK with heat pumps, higher temperature output means lower coefficient of
performance?

there are two stage heatpumps and heatpumps with auxiliary immersion heaters

--
In theory, there is no difference between theory and practice.
In practice, there is.
-- Yogi Berra

newshound

2022-01-09 10:33:34 UTC

Post by Tim+
Kinda telling that there’s no mention of COP anywhere in the info for this
heat pump. I guess they’re hoping that people won’t notice that it’s gonna
be even more expensive than gas heating or a “regular” ASHP until too late.

They're using CO2 (R744) as the refrigerant instead of the common R32. COP
https://deepresource.wordpress.com/2021/11/18/vattenfall-offers-high-temperature-heat-pump/
(the sources are in Dutch)
Theo

OH NO NOT CO2, WHAT HAPPENS IF IT LEAKS OUT :-)

Theo

2022-01-10 10:48:48 UTC

They're using CO2 (R744) as the refrigerant instead of the common R32. COP
https://deepresource.wordpress.com/2021/11/18/vattenfall-offers-high-temperature-heat-pump/
(the sources are in Dutch)

OH NO NOT CO2, WHAT HAPPENS IF IT LEAKS OUT :-)

It has a GWP of 1, compared with a GWP of 677 for R32, and 2088
for R410A. So you can breathe easy :-)

(a bigger problem is the R134A - GWP 1430 - in cars, which seem to
perpetually leak given the number of regas services available. The R1234yf
in newer cars has a GWP of 4, so that's better)

Theo

The Natural Philosopher

2022-01-10 11:54:04 UTC

They're using CO2 (R744) as the refrigerant instead of the common R32. COP
https://deepresource.wordpress.com/2021/11/18/vattenfall-offers-high-temperature-heat-pump/
(the sources are in Dutch)

OH NO NOT CO2, WHAT HAPPENS IF IT LEAKS OUT :-)

It has a GWP of 1, compared with a GWP of 677 for R32, and 2088
for R410A. So you can breathe easy :-)
(a bigger problem is the R134A - GWP 1430 - in cars, which seem to
perpetually leak given the number of regas services available. The R1234yf
in newer cars has a GWP of 4, so that's better)
Theo

All bollocks since global warming isn't a problem and isn'tt happening
very much and is beneficial where it is.

--
“Some people like to travel by train because it combines the slowness of
a car with the cramped public exposure of  an airplane.”

Dennis Miller

Andrew

2022-01-17 17:24:36 UTC

Post by Tim+
Kinda telling that there’s no mention of COP anywhere in the info for this
heat pump. I guess they’re hoping that people won’t notice that
it’s gonna
be even more expensive than gas heating or a “regular” ASHP until too late.

They're using CO2 (R744) as the refrigerant instead of the common
R32. COP
https://deepresource.wordpress.com/2021/11/18/vattenfall-offers-high-temperature-heat-pump/
(the sources are in Dutch)

OH NO NOT CO2, WHAT HAPPENS IF IT LEAKS OUT :-)

It has a GWP of 1, compared with a GWP of 677 for R32, and 2088
for R410A. So you can breathe easy :-)
(a bigger problem is the R134A - GWP 1430 - in cars, which seem to
perpetually leak given the number of regas services available. The
R1234yf
in newer cars has a GWP of 4, so that's better)
Theo

All bollocks since global warming isn't a problem and isn'tt happening
very much and is beneficial where it is.

Try traveling around some of the islands in the South Pacific and
you will see the non-beneficial effect.

tony sayer

2022-01-21 09:40:26 UTC

Post by Tim+
Kinda telling that there’s no mention of COP anywhere in the info for this
heat pump. I guess they’re hoping that people won’t notice that
it’s gonna
be even more expensive than gas heating or a “regular” ASHP until too late.

They're using CO2 (R744) as the refrigerant instead of the common
R32. COP
https://deepresource.wordpress.com/2021/11/18/vattenfall-offers-high-

temperature-heat-pump/

(the sources are in Dutch)

OH NO NOT CO2, WHAT HAPPENS IF IT LEAKS OUT :-)

It has a GWP of 1, compared with a GWP of 677 for R32, and 2088
for R410A. So you can breathe easy :-)
(a bigger problem is the R134A - GWP 1430 - in cars, which seem to
perpetually leak given the number of regas services available. The
R1234yf
in newer cars has a GWP of 4, so that's better)
Theo

All bollocks since global warming isn't a problem and isn'tt happening
very much and is beneficial where it is.

Try traveling around some of the islands in the South Pacific and
you will see the non-beneficial effect.

Yes South Georgia is much the same latitude as Manchester yet still
seems to have snow capped mountains most of the year...

--
Tony Sayer

Man is least himself when he talks in his own person.

Give him a keyboard, and he will reveal himself.

Andrew

2022-01-21 14:53:06 UTC

Post by tony sayer

Post by Tim+
Kinda telling that there’s no mention of COP anywhere in the info for this
heat pump. I guess they’re hoping that people won’t notice that
it’s gonna
be even more expensive than gas heating or a “regular” ASHP until too late.

They're using CO2 (R744) as the refrigerant instead of the common
R32. COP
https://deepresource.wordpress.com/2021/11/18/vattenfall-offers-high-

temperature-heat-pump/

(the sources are in Dutch)

OH NO NOT CO2, WHAT HAPPENS IF IT LEAKS OUT :-)

It has a GWP of 1, compared with a GWP of 677 for R32, and 2088
for R410A. So you can breathe easy :-)
(a bigger problem is the R134A - GWP 1430 - in cars, which seem to
perpetually leak given the number of regas services available. The
R1234yf
in newer cars has a GWP of 4, so that's better)
Theo

All bollocks since global warming isn't a problem and isn'tt happening
very much and is beneficial where it is.

Try traveling around some of the islands in the South Pacific and
you will see the non-beneficial effect.

Yes South Georgia is much the same latitude as Manchester yet still
seems to have snow capped mountains most of the year...

But that is the South Atlantic and quite near to Antarctica, not the
South Pacific

tony sayer

2022-01-24 09:07:16 UTC

Post by Andrew

Post by tony sayer

Post by Tim+
Kinda telling that there’s no mention of COP anywhere in the info for this
heat pump. I guess they’re hoping that people won’t notice that
it’s gonna
be even more expensive than gas heating or a “regular” ASHP until
too late.

They're using CO2 (R744) as the refrigerant instead of the common
R32. COP
https://deepresource.wordpress.com/2021/11/18/vattenfall-offers-high-

temperature-heat-pump/

(the sources are in Dutch)

OH NO NOT CO2, WHAT HAPPENS IF IT LEAKS OUT :-)

It has a GWP of 1, compared with a GWP of 677 for R32, and 2088
for R410A. So you can breathe easy :-)
(a bigger problem is the R134A - GWP 1430 - in cars, which seem to
perpetually leak given the number of regas services available. The
R1234yf
in newer cars has a GWP of 4, so that's better)
Theo

All bollocks since global warming isn't a problem and isn'tt happening
very much and is beneficial where it is.

Try traveling around some of the islands in the South Pacific and
you will see the non-beneficial effect.

Yes South Georgia is much the same latitude as Manchester yet still
seems to have snow capped mountains most of the year...

But that is the South Atlantic and quite near to Antarctica, not the
South Pacific

Yes it is but the same Latitude doesn't have that the benefit of the
gulf stream?...

--
Tony Sayer

Man is least himself when he talks in his own person.

Give him a keyboard, and he will reveal himself.

Spike

2022-01-09 09:40:02 UTC

Post by PeterC
https://www.theguardian.com/environment/2022/jan/07/new-heat-pump-could-ease-uk-shift-to-low-carbon-homes-say-developers
As it's European - and I'd guess that the Swedes know a bit about heating -
this might just work.
No links to the manufacturer, as there's FA useful on the site - only what
is in the Guardithingy.

And as one might expect from the Guardian, the piece is essentially
about insulating homes; it's mentioned in more than half the article.

--
Spike

Andrew

2022-01-17 17:35:42 UTC

I installed an AS heatpump in 2005, a prefilled self-fit split unit with
outside and inside parts linked by pipework and a cable. Somewhat to my
surprise, almost 17 years later, it's still working fine and has never
needed any maintenance, except for pulling out any weeds that start
growing into the outdoor part.

Can you remember the make ?

Andrew Gabriel

2022-01-29 14:32:36 UTC