Heat Pumps: anyone have one/thought about it?

PermaChanged said:
We didn't really give much consideration to the distance between the heat pump and the hot water cylinder and the UFH manifold, are we losing much in the way of having long runs? I'd estimate that there's a good 15m+ of pipe between the heat pump and the cylinder, then a further 8m from cylinder to manifold!! Guess we're losing a fair amount of heat along the route, will do my best to ensure the insulation is as good as can be.


Heat pump is outside, under the kitchen window - 28mm glow and return pipework comes through the soffit, through the flat part of the vaulted ceiling (completely inaccessible now!), through eaves cupboards in the vaulted mezzanine area, then in to attic space down the length of the house, before going across in to what will be the family bathroom. Then that returns to the manifold in 22mm pipework.
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The most recent job I did, the pipework was under the ground and ran for around 20m before entering the house, then a further 10m inside which wasn’t a problem,

The main problem was wind, the condenser was out on the open. So they wind chill was playing a major effect with its performance,

Moved it to here from the other side of the building - https://flic.kr/p/2pfZX9U

Main buffer tank installed and flow and return pipes routed through to there plant room - https://flic.kr/p/2pg6DNa

Then the main plant room, with the water tank, pumps, manifolds, and ASHP boiler - https://flic.kr/p/2pg7fYg

Cheers
 
PishY said:
House insulation is everything for a heatpump, for it to be efficient anyway !
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That’s a common misconception which isn’t actually true.

Regardless of the source of heating, all insulation does is mean you consume less energy and therefore burn less money.

Less insulation = higher heat loss. Just like a gas boiler, you should size the heat pump and the radiators to the heat loss.

System design is the thing impacts efficiency. Bad design, bad efficiency, good design, good efficiency.
 
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b0rn2sk8 said:
That’s a common misconception which isn’t actually true.

Regardless of the source of heating, all insulation does is mean you consume less energy and therefore burn less money.

Less insulation = higher heat loss. Just like a gas boiler, you should size the heat pump and the radiators to the heat loss.

System design is the thing impacts efficiency. Bad design, bad efficiency, good design, good efficiency.
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Still it's pointless upgrading your boiler for heat pump if your insulation is crap.

Better to improve insulation first
 
b0rn2sk8 said:
That’s a common misconception which isn’t actually true.

Regardless of the source of heating, all insulation does is mean you consume less energy and therefore burn less money.

Less insulation = higher heat loss. Just like a gas boiler, you should size the heat pump and the radiators to the heat loss.

System design is the thing impacts efficiency. Bad design, bad efficiency, good design, good efficiency.
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Oh yes I totally agree, but get the basics right first which is always the house insulation, what’s the point in heating a house with poor insulation regardless of what heat source you’re installing.

I get the energy assessment forms, the SAP reports, which will include insulation, window specs, doors, etc and then I’ll design and specify a heatpump to work within that tolerance and what will happily pass all inspections going forward once it’s complete, I’ll also always use the heatpump manufacturers design team for projects

You seem very knowledgeable you in the trade to?
 
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PishY said:
You seem very knowledgeable you in the trade to?
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I’ll take the compliment but no. I’m just a nerd with way too much spare time combined with someone who will not part with any meaningful amount of money without knowing exactly what they’re getting.

It’s problematic sometimes :p
 
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PishY said:
which will include insulation, window specs, doors, etc and then I’ll design and specify a heatpump to work within that tolerance and what will happily pass all inspections going forward once it’s complete
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Do you know of any online calculators which do a thorough job?

I'm really struggling to find something to work out our heat loss to see whether we were specced the correct sized heatpump by our installer - most online calcs only show when there's 100mm of loft roll insulation used!

For reference we're a cavity built bungalow with 90mm of external wall insulation, 300mm loft insulation and 50mm floor insulation.
 
PermaChanged said:
Do you know of any online calculators which do a thorough job?

I'm really struggling to find something to work out our heat loss to see whether we were specced the correct sized heatpump by our installer - most online calcs only show when there's 100mm of loft roll insulation used!

For reference we're a cavity built bungalow with 90mm of external wall insulation, 300mm loft insulation and 50mm floor insulation.
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It isn't an exact science I don't think.
 
PermaChanged said:
Do you know of any online calculators which do a thorough job?

I'm really struggling to find something to work out our heat loss to see whether we were specced the correct sized heatpump by our installer - most online calcs only show when there's 100mm of loft roll insulation used!

For reference we're a cavity built bungalow with 90mm of external wall insulation, 300mm loft insulation and 50mm floor insulation.
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A spreadsheet will do this.

Heat loss = Area of element x U value x temperature difference between inside and outside.

So work out the areas of each of the external walls, windows (take away window area from wall area), doors, roof and floors.

U values will be 0.26 for walls, roof 0.14, Walls 0.35, Floor 0.35, doors and windows 3.3. It will vary depedant type on insulation.

Then add 0.33 x the volume of your house to this.
 
PermaChanged said:
Do you know of any online calculators which do a thorough job?

I'm really struggling to find something to work out our heat loss to see whether we were specced the correct sized heatpump by our installer - most online calcs only show when there's 100mm of loft roll insulation used!

For reference we're a cavity built bungalow with 90mm of external wall insulation, 300mm loft insulation and 50mm floor insulation.
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Heatpunk.co.uk

Spend a few hours on it, inputting you home fabric makeup and it'll get pretty close.

The heat geek estimator gets pretty close, for me anyway and took about 10 seconds to do.
 
PishY said:
Air 2 air Heatpumps, basically air-conditioning systems, I’ve fitted hundreds of these in domestic property’s, from wallmounted ones, to ducted, to floor mounted,

They are great as they heat the air up in the room quickly so you feel the benefit fast

I’ve fitted a few multi systems recently, it had 5 indoor units from one condenser outside, so they had ac in each 3 of the bedrooms, the lounge and then the kitchen/diner, they don’t use there radiators now and solely that for heat and the efficiency is great, for every 1KW they use of electric the AC outputs nearly 4KW of heat, which is remarkable !
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Out of interest, what kind of ducted systems do people typically have fitted in the UK?

I've looked into it a couple of times and I guess I'm not using the right terminology because I just couldn't find anything similar to the US.

I had an air-con specialist round to survey the house, and he was very strongly of the view that the only realistic option was choosing a handful of rooms and giving each of those a specific wall mounted a/c. Certainly at some point I'd really like to have a US-style centralised HVAC system.
 
PermaChanged said:
That looks great, will give it a bash when I've got some time - thank you.
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would still think that getting Home-assistant type access, to log the HP heat output is essential, so you could see outside temp, electric in, heat needed to sustain indoor temp,
which would show overall U value for house W/dT
 
If my bills are higher than I'd like/anticipated I will look in to investing in proper monitoring - I think proper insulation is a more cost effective solution at this juncture though.
 
PermaChanged said:
I think our heat pump is noisier than it should be, can anyone confirm whether this level of noise is normal?

It's definitely compressor side of things rather than the fan, it's noisier than I had hoped for if this is normal!

youtu.be

Mitsubishi Ecodan 11.2kw heat pump compressor noise - is this normal?

youtu.be youtu.be
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Agree - not normal.

Sounds like something has gone -fan bearings maybe? I’m just a homeowner so no idea but sounds like it’s time to get it serviced and repaired!
 
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