Anyone here experience fitting air source heating?

[Michael Kilpatrick]

Curious to know of anyone - but not a new build, something pre 1980s -
who has fitted air source heating to their house? And perhaps installed
compact fan-assisted radiators such as the Dimplex SmartRad and
such-like, where space was at a premium and to use lower flow temperatures?

I'm keen to have recommendations of professionals to discuss the
possibilities.


Michael

[The Natural Philosopher]

Post by Michael Kilpatrick
Curious to know of anyone - but not a new build, something pre 1980s -
who has fitted air source heating to their house? And perhaps installed
compact fan-assisted radiators such as the Dimplex SmartRad and
such-like, where space was at a premium and to use lower flow temperatures?
I'm keen to have recommendations of professionals to discuss the
possibilities.

I have fan assisted rads but they need 50 C water to switch on.

Really they haven't been very successful. They are noisy, and whilst
they do put out a decent amount of warmth, its fairly localised.

In a low temp retrofit of UFH is not possible, I'd be inclined to lay a
new wall surface on an outside wall with water pipes coiled behind it.

The issue boils down to simple physics - at lower temps you need more
radiative/convective surface. If you cant use the best option - the
floor - then a wall is next best.

Radiators are not great - ugly and huge. And trap dust

I'll pass on heatpumps. Looked at them and at the time not cost
effective, and now with gas prices pushing electric prices through the
roof, not very useful today either.

Once the grid is all nuclear, probably worth looking at simple resistive
electric heating.

Air source is really not that useful as when you need the most power -
very low outside temperatures - it is at its least efficient.

Ecobollox™ is the order of the day with anything that's being promoted
as anything other than a cost effective way to heat a house. And if you
think legislation is there to ensure that technology no one would touch
otherwise, is *mandatory*, you are Green and wet behind the ears...

Post by Michael Kilpatrick
Michael

[Theo]

Post by Michael Kilpatrick
Curious to know of anyone - but not a new build, something pre 1980s -
who has fitted air source heating to their house?

We fitted a Grant ASHP in December. So far it's holding up OK - 1960s
chalet bungalow, somewhat draughty. About 25-30kWh per day on the coldest
days. I suspect this could be improved quite a bit - see below.

Post by Michael Kilpatrick
I'm keen to have recommendations of professionals to discuss the
possibilities.

Installer was Shelford Heating, but I wouldn't recommend them. They've
basically installed it like a boiler, and heat pumps really shouldn't be
installed that way (they should keep running while modulating their flow
temp down, rather than using an on/off thermostat like a boiler). There
were some egregious faults (they left site with the radiators unbalanced and
the system full of air) and they're still due to come back and sort things
out.

Some posts about about my experience:
https://renewableheatinghub.co.uk/forums/renewable-heating-air-source-heap-pumps-ashps/share-your-electricity-bills
https://renewableheatinghub.co.uk/forums/renewable-heating-air-source-heap-pumps-ashps/install-a-grant-aerona-13kw-instead-of-mitsubishi-ecodan-11-2kw#post-6532
https://renewableheatinghub.co.uk/forums/renewable-heating-air-source-heap-pumps-ashps/whilst-regs-allow-on-off-simple-thermostats-nest-hive-heatmiser-honeywell-etc-installers-should-never-be-responsible-for-failing-heat-pumps#post-6483

Post by Michael Kilpatrick
And perhaps installed compact fan-assisted radiators such as the Dimplex
SmartRad and such-like, where space was at a premium and to use lower flow
temperatures?

I'm looking at ordering some fan coil units from Italy or China to do
cooling, which the Dimplex SmartRads won't do (the same idea, but you need
condensate collection):
https://renewableheatinghub.co.uk/forums/renewable-heating-air-source-heap-pumps-ashps/chilled-water-ac-system#post-5949

My Grant doesn't officially admit to offering cooling, but it's a rebadge
of a Chofu unit that does. The cooling function has enabled in settings - I
await a warm day to test it before I'll go ahead with FCUs. Shelford don't
know anything about cooling, so that bit is down to me.


A brief roundup of things I found useful:

A book on the basics, worth reading for the background:
https://www.amazon.co.uk/Heat-Pumps-Home-John-Cantor/dp/1785007793

https://renewableheatinghub.co.uk/
particularly the forums and videos, also:
https://forum.buildhub.org.uk/forum/119-air-source-heat-pumps-ashp/

This YT channel is good - they focus on the idea of system design to
maximise efficiency, rather than the boiler installer slap in the biggest
and hope for the best. They have training courses which are one of the main
heatpump installer courses - I'd look for installers who have done the
course (there's a list on their site), rather people slapping them in like
boilers:
https://www.youtube.com/c/HeatGeek
https://www.heatgeek.com/find-a-heat-geek/

(the MCS is another certification scheme, but seems a lot of MCS certified
people don't really know what they're doing as far as heat pump efficiency
goes)

Another YT training channel, useful in understand how all the parts fit
together:
https://www.youtube.com/c/FreedomHeatpumps

Happy to answer any questions that I can...

Theo

[Michael Kilpatrick]

Post by Theo

Post by Michael Kilpatrick
Curious to know of anyone - but not a new build, something pre 1980s -
who has fitted air source heating to their house?

We fitted a Grant ASHP in December. So far it's holding up OK - 1960s
chalet bungalow, somewhat draughty. About 25-30kWh per day on the coldest
days. I suspect this could be improved quite a bit - see below.

Post by Michael Kilpatrick
I'm keen to have recommendations of professionals to discuss the
possibilities.

Installer was Shelford Heating, but I wouldn't recommend them. They've
basically installed it like a boiler, and heat pumps really shouldn't be
installed that way (they should keep running while modulating their flow
temp down, rather than using an on/off thermostat like a boiler). There
were some egregious faults (they left site with the radiators unbalanced and
the system full of air) and they're still due to come back and sort things
out.

Thanks Theo, I shall try and look at all of those links tomorrow.

But I didn't know the above. You're saying the water in the CH radiator
circuits will be flowing all the time, day and night, in a sensible
set-up? That's curious.



Michael

[Theo]

Post by Michael Kilpatrick
Thanks Theo, I shall try and look at all of those links tomorrow.
But I didn't know the above. You're saying the water in the CH radiator
circuits will be flowing all the time, day and night, in a sensible
set-up? That's curious.

Basically, the heatpump works more efficiently the lower the flow (output)
temperature. That means a lower output for longer is better than a high
output for a shorter period.

In the optimal state, the HP will be balancing the losses from your house -
eg if your house has say 5kW of losses on a freezing day, then the HP only
needs to put in 5kW. It is more efficient to have the HP outputting a
constant 5kW than to have it outputting 10kW for half the time and cycling
50/50 like a boiler. A 5kW HP is also smaller and more efficient than
modulating down a 10kW HP.

However if you turn off the 5kW HP and the house gets cold, it'll take a
long time to bring it up to temperature again. 5kW losses might be at 20C
inside, if it's 10C inside the losses might be 3kW - the 5kW can still make
progress in raising the temperature (net input 2kW), but it'll struggle to
reach target where the losses are balancing. A bigger HP can swing the
temperature faster.

This is in the depths of winter. I think in spring and autumn when you
don't need a lot of heat then it will still modulate.

That said, we have a quite large (13kW) unit and it's being modulated every
20 mins thanks to the incorrect controls they're installed, and we turn it
off at night for noise reasons. It works fine (a bit slow to warm up in the
morning compared with the previous boiler), but probably efficiency is
taking a hit.

Theo

[Mark Carroll]

Post by Theo
However if you turn off the 5kW HP and the house gets cold, it'll take a
long time to bring it up to temperature again.

Mmmm, in that kind of case, my house's HP adds in resistive heat too,
obviously killing efficiency rather. It doesn't if I've not turned it
off or down far though, it's more like, I got back from holidays or
whatever, and now I've asked it to raise by many degrees.

-- Mark

[Theo]

Post by Mark Carroll

Post by Theo
However if you turn off the 5kW HP and the house gets cold, it'll take a
long time to bring it up to temperature again.

Mmmm, in that kind of case, my house's HP adds in resistive heat too,
obviously killing efficiency rather. It doesn't if I've not turned it
off or down far though, it's more like, I got back from holidays or
whatever, and now I've asked it to raise by many degrees.

Mine can do that - there's an immersion in the buffer tank and an output to
control it - but it's not wired up. Generally HP installers don't like
doing that because it's an easy way to get unexpected bills if the HP is
incorrectly configured.

It's safer not to have it - although perhaps might be useful if we ever got
a -20C winter. And I agree there are rare occasions where you want the
'just make it hot asap dammit' and it would be useful for that. Perhaps I
could wire it on a manual switch or something, for emergency purposes
only...

Theo

[The Natural Philosopher]

Post by Theo

Post by Mark Carroll

Post by Theo
However if you turn off the 5kW HP and the house gets cold, it'll take a
long time to bring it up to temperature again.

Mmmm, in that kind of case, my house's HP adds in resistive heat too,
obviously killing efficiency rather. It doesn't if I've not turned it
off or down far though, it's more like, I got back from holidays or
whatever, and now I've asked it to raise by many degrees.

Mine can do that - there's an immersion in the buffer tank and an output to
control it - but it's not wired up. Generally HP installers don't like
doing that because it's an easy way to get unexpected bills if the HP is
incorrectly configured.
It's safer not to have it - although perhaps might be useful if we ever got
a -20C winter.

Do you really think a bunch of mediaeval windmills and solar panels are
going to allow any access to electricity in a -20°C winter?

And I agree there are rare occasions where you want the

Post by Theo
'just make it hot asap dammit' and it would be useful for that. Perhaps I
could wire it on a manual switch or something, for emergency purposes
only...
Theo

[Brian Morrison]

On Thu, 24 Feb 2022 16:06:43 +0000

Post by The Natural Philosopher
Do you really think a bunch of mediaeval windmills and solar panels are
going to allow any access to electricity in a -20°C winter?

After today's events there needs to be an immediate and effective
change in UK energy policy. Net zero needs to go in the bin where it
should always have been and we should immediately begin formulating a
strategy to get back to where we were with domestic nuclear industry in
the 50s 60s and 70s.

[Tim Ward]

Post by Theo
Perhaps I
could wire it on a manual switch or something, for emergency purposes
only...

In this household such devices are called "fan heaters". Which you have
to have anyway for when the central heating breaks down.

[Tim Ward]

we turn it off at night for noise reasons

Yes, I've read that the things are noisy. Not encouraging. Our existing
gas central heating is almost silent. (Well, it is after I had the
system desludged and the pump replaced.)

[Theo]

Post by Tim Ward

we turn it off at night for noise reasons

Yes, I've read that the things are noisy. Not encouraging. Our existing
gas central heating is almost silent. (Well, it is after I had the
system desludged and the pump replaced.)

Noise-wise it's a lot quieter than our oil boiler (no 'click <pause>
whoomf') - there's a bit of buzzing ourside, but inside it's no more than a
fridge or regular central heating pump. I'm fine with it, but a family
member is however ultra noise sensitive, which means we're paranoid about
noise.

The main issue for me is the dozy installer decided to mount the pipework
and relay boxes on a solid wall adjoining the bedroom, with regular screws.
So all the contactor clunking and the pump running transmits through the
wall. It's a bit like trying to sleep in the airing cupboard.

Theo

[tony sayer]

In article <oLf****@news.chiark.greenend.org.uk>, Theo <theom+***@chi
ark.greenend.org.uk> scribeth thus

Post by Theo

Post by Tim Ward

we turn it off at night for noise reasons

Yes, I've read that the things are noisy. Not encouraging. Our existing
gas central heating is almost silent. (Well, it is after I had the
system desludged and the pump replaced.)

Noise-wise it's a lot quieter than our oil boiler (no 'click <pause>
whoomf') - there's a bit of buzzing ourside, but inside it's no more than a
fridge or regular central heating pump. I'm fine with it, but a family
member is however ultra noise sensitive, which means we're paranoid about
noise.
The main issue for me is the dozy installer decided to mount the pipework
and relay boxes on a solid wall adjoining the bedroom, with regular screws.
So all the contactor clunking and the pump running transmits through the
wall. It's a bit like trying to sleep in the airing cupboard.
Theo

Where else might he have put them I'd not expect an installer to think
of that aspect;!...

[Theo]

Post by tony sayer
ark.greenend.org.uk> scribeth thus

Post by Theo
The main issue for me is the dozy installer decided to mount the pipework
and relay boxes on a solid wall adjoining the bedroom, with regular screws.
So all the contactor clunking and the pump running transmits through the
wall. It's a bit like trying to sleep in the airing cupboard.

Where else might he have put them I'd not expect an installer to think
of that aspect;!...

There was a perfect good wall at 90 degrees to the bedroom, which is where
the existing pipework was and where I told them to put things...

Meanwhile, rubber lined pipe clips are 36p+VAT...

Theo

[tony sayer]

In article <nLf****@news.chiark.greenend.org.uk>, Theo <theom+***@chi
ark.greenend.org.uk> scribeth thus

Post by Theo

Post by tony sayer
ark.greenend.org.uk> scribeth thus

Post by Theo
The main issue for me is the dozy installer decided to mount the pipework
and relay boxes on a solid wall adjoining the bedroom, with regular screws.
So all the contactor clunking and the pump running transmits through the
wall. It's a bit like trying to sleep in the airing cupboard.

Where else might he have put them I'd not expect an installer to think
of that aspect;!...

There was a perfect good wall at 90 degrees to the bedroom, which is where
the existing pipework was and where I told them to put things...
Meanwhile, rubber lined pipe clips are 36p+VAT...
Theo

Right i see! Mind you every bloody drawing I've ever done i always put;

"IF IN DOUBT ASK" complete with a 24 hour phone number.

Do they ever ask?, do they feck!....