Speaking of cooking the house... I'm finding now it's mild outside I'm having the issue again where the LWT is running miles above where it should be on the weather curve. At 12C outside temp, it should be running at a LWT of 31C according to the weather curve, but instead it is sat at 35C and making the house far too hot. The irony is it's running very nicely, with power use of about 400w and a COP of about 5, but I'd prefer it to run where it should so we don't bake!
Heat Pumps: anyone have one/thought about it?
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Associate
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Gutted - heat pump plan had to be abandoned due to a pair of vertical radiators in the extension built by the previous owners in 2012. 10mm plastic piping that would take thousands to refit to 15mm copper and can’t take the throughput (1000kW rated vs 2975kW needed according to Octopus).
Part of me is relieved there won’t be a big grey and pink box in the back garden but mostly annoyed that a bit of corner cutting 15 years before we bought the place has kiboshed our low carbon plan.
Part of me is relieved there won’t be a big grey and pink box in the back garden but mostly annoyed that a bit of corner cutting 15 years before we bought the place has kiboshed our low carbon plan.
Are you sure you need nearly 3kW there? My whole house heat demand was estimated at about 5kW or 6kW at -5 and actually hasn't ever needed more than 4.5kW in the depths of winter. Must be a pretty large extension and/or poor insulation?
You can always try to run a greater dT e.g. Nibe is around 7, with bigger radiators.
You can always try to run a greater dT e.g. Nibe is around 7, with bigger radiators.
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I honestly have no idea, I’m not an engineer and can only go off what I’m told. The pipe/wire run from the pump to the loft would have been nightmarish, we’d have needed custom made brackets to hold the water tank and although we’re having the insulation done the vertical rads are too far from the manifold to make redoing the pipes economically viable.
We’ll consider it for the next property but we’ve got a gas boiler being installed on Tuesday
We’ll consider it for the next property but we’ve got a gas boiler being installed on Tuesday
Yeah that's what boils my wee about the industry at the moment. Yes I am an engineer but you really shouldn't have to be one to get someone willing to spend some effort working out what's needed not just slapping the same thing in everywhere. Unfortunately that's all octopus do, and the people that are willing/competent to do some design work seem to be busy not to mention rare.
Nothing to do with you of course, you're not even the first person I've talked to with the same outcome but just a general rant.
Nothing to do with you of course, you're not even the first person I've talked to with the same outcome but just a general rant.
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Yeah, the plan was to go all electric, zero gas, with solars/battery/ev charger and be all but self-sufficient, but the half-arsed pipes on just two bloody radiators kiboshed it.
We'll get the house knocked into shape, sort out the other bits where the previous owners cheaped out such as the internal doors and try to put some value on it before considering a move.
We'll get the house knocked into shape, sort out the other bits where the previous owners cheaped out such as the internal doors and try to put some value on it before considering a move.
Not really corner cutting as heat pumps were not really on anybodies list fifteen years ago and 10mm plastic was a standard a few years back. Mot that I like the stuff.
But yeah we went with a new gas boiler last May as we felt the upgrades to our sixties semi were too onerous to contemplate. Leave it to the next owner.
I have a 4KW Daikin at the back of my 2 bed mid-terrace. I had 15mm copper throughout. 10mm plastic/copper is OK but it gets a bit tight on 8mm plastic because of the internal restriction.
I have the DHW tank and expansion etc. in the loft. The Daikin HP is below the kitchen window and even with single glazing you can barely hear it unless you open the window. Just fan noise with a mere hint of pump noise when flat out doing the hot water for ~30mins once a day.
I have noticed when mild i.e. above 10C my Daikin was overshooting less maybe .2 - .5C
As soon as the outside temp dropped to 7C it went back to the full 1.5C overshoot. No issue as by then it's idling at 300W and does shut off.
Thank you so much. We are in similar positions house wise then. Can you recall what it cost to get installed and who did you go with for it?
And forgive me asking, is it working out for you?
My boiler packed in, I have a complicated install according to British Gas and they have just tried to pump me for £7800 LOL
Octopus. I was early and had mine installed at a low cost when they were still getting their systems sorted. Working yes but my small 2 bed mid-terrace with good insulation vexes the heat pump in a good way. The 4KW Daikin is a software restricted unit with the same bits as the 6KW & 8KW heat pumps. Sometimes it struggles to idle down enough so slowly overshoots by a degree or so then shuts off. Nothing wrong with that as it doesn't work very hard most of the time just slightly annoying if you want perfectly controlled temps.
Now I would be charged between £4k - £6K for the same installation. Same my boiler was 30 years old and needed replacing. Due to the units age it would have been a £3.5K install anyway for a full modern system replacement.
Have you tried Heatgeek, there are some installers in your area, presuming its Stoke-on-Trent, you'd get a far better install as well.
Heat Geek - Heat pump installs from the world's best installers
Heat Geek makes it easy for homeowners to save money on their bills with AI designed, efficient heat pump systems.
www.heatgeek.com
I'm mid terrace with 8mm copper
Thanks. At least I'm not dreaming by looks of it.
I had not and I'm in NUL so all good. Was in Manchester for 12 years and then moved back.Have you tried Heatgeek, there are some installers in your area, presuming its Stoke-on-Trent, you'd get a far better install as well.
Heat Geek - Heat pump installs from the world's best installers
Heat Geek makes it easy for homeowners to save money on their bills with AI designed, efficient heat pump systems.
I've looked through Octupus and it looks like without any surprises for the installers it will be around 5k. Thanks for all that.
I ran my address through both the Heat Geek & Octopus estimate tools and firstly they are both much closer to my actual install requirements. They have both learnt a lot over the last 2 years especially Heat Geek due to their data driven tools.
Heat Geek details below closely match my actual requirements. I added the new cylinder option as I know my ancient one was small and poorly insulated. 3 rads were changed by Octopus in my current install though I did the last two myself. Unnecessarily as it turns out. Previous heat loss was calculated to be 3.2KW but in reality from live readings appears to be around 2.25KW @ -3C. Heat Geek is much closer allowing for a error margin on top at 2.91KW.
IMHO the Octopus 6KW heat pump would be too big for my house.
Heat Geek Vaillant 5KW would be my choice now.
Heat Geek - £3900
Octopus - £3700
Original Octopus quote - 4KW Daikin
Final quote for the ASHP installation £880.69
Likely extras for both install options
EPC £65.00
Planning £328.00 - At the time was for noise and boundary
Structural survey £500-700 for airing cupboard over stairs but expanded to loft space
Enlarge loft hatch ~£50.00 - DHW cylinder located to loft
Additional external wall ducting £155.00 (included now)
Artex asbestos test £250 - Flippin Octopus being super cautious.
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Let us know how you get on with Heatgeeks, at least you appear to have three nearby. If you like you're data accurate they can fit an Open Energy Monitoring system.
Soldato
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I work in the commercial heat pump market. Implementation has been crap. SALIX funding has, fortunately, ended. But all those buildings whose gas boiler has just been straight up replaced with a heat pump are going to be getting some hefty bills this winter.
I know of once instance where a local authority replaced their 1.1 MW of gas boilers with 1.1 MW of heat pumps. We monitor their heat network. Their peak demand so far has been 180 kW.....would have taken ten minutes of looking at energy data to work this out.
Imbeciles.