Heat Pumps: anyone have one/thought about it?

Sounds good, did you work out in cost on bills with the estimate with what you are paying in gas and electric now. All these COP numbers means nothing in cost if gas prices fall and electricity price up etc :)
 
So while I'm sceptical, are you saying that the entirety of the installing is going to cost 900 quid? At that price I'd be tempted to do it before the boiler breaks.
 
Coran said:
I can’t imagine they’ll be offering a £7.5k grant forever. That’s a pretty impressive offer compared to the cost of a new boiler. Do you expect to need to do much fixing up after? Are they just switching things where they are rather than replacing pipes all over the place (which will require repainting etc)?
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All pipes in my house go to the garage where the boiler is.
Where the cylinder needs to go though is currently my washing machine and dryer, plus some built in racking.

One thing I'd like to see is compensation if things don't actually work out cheaper. I'm still undecided, which in itself tells me to leave it for now.
 
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China Man said:
Hence the grant of £7500 to help to switch people over, forget about the ROI and all that for a second and just look at it as £7500 free money. Not all houses need massive amount of work to keep the COP above 4 (wet finger in the air number for ASHP to be as cheap as gas with current prices per unit). That is what grant is, free money. Same goes to employer contribution pension matching your contribution, you don't use it you gets nothing.



I have solar and battery and running of Octopus Go traiff, although solar don't provide nearly enough to run just the house let alone the ASHP in winter it does not mean it would not help with cost in terms of money. My night 4 hours rate is 7.5p and having the battery means that anything I use during the day will cost 7p *correction 9p now* instead of 32p which is a massive difference.

For ASHP to work or worth changing in my house it needs to be COP 4, this is to do with gas prices and electricity prices. ASHP will use more electricity but my gas bill will reduce (I will cook as we need the Wok Hei), to compensate the increased electricity use I have ripple wind farm and also the solar farm which hopefully give me money back just as I would use electricity at cheaper rate.

If COP drops to 3 and below that would really mess up my calculations and of course if gas prices drop to 35% of current price then it would be a disaster too. I won't cry if my system shows a COP 2.5 but it just meant I wasted the governments £7500 etc.

If I recall correctly there was grant many years back when you insulate your house you get money from governments which also had a lot of criticism, a lot of people are saying insulation your house will yield more benefit than changing gas to ASHP which I agree but it has already been done to death.
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For this to make any sense you are saying you installed batteries that store more then your daily usage
Thats semi unusual, most people dont as there is little point. Your paying more money and will push out the ROI in that case.

When I looked into adding more to my system I calculated that going from around 60% battery to usage ratio, to around 90% usage ratio for the incremental battery spend push that part out to around 10 years ROI.
And that was with a higher difference between go and current pricing, which will push that out even further.

Wether go makes sense or cosy makes more sense is going to depend on the ratio of your house usage vs your HP usage.
So again the equation will vary property to property, person to person.
 
robj20 said:
Octopus have come back with £900 for everything including a hot water tank.

So with previous calculations that would take 7 years to pay off, then £122 a year better of Vs gas. What are the chances it will still be £900 when my boiler needs replacing.
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Its going to be difficult to judge IMO
To encourage transition the costs HAVE to be similar IMO, and as such as the prices to install fall (there really is not reason they should increase as more demand and more competition happens) then maybe the grants will fall
I am pretty convinced they will need to offer some grants over time to stop a massive push back.

Eventually once gas is fringe maybe the truer cost will have to be accepted and not be subsidised.
 
For this to make any sense you are saying you installed batteries that store more then your daily usage
Thats semi unusual, most people dont as there is little point. Your paying more money and will push out the ROI in that case.

When I looked into adding more to my system I calculated that going from around 60% battery to usage ratio, to around 90% usage ratio for the incremental battery spend push that part out to around 10 years ROI.
And that was with a higher difference between go and current pricing, which will push that out even further.

Wether go makes sense or cosy makes more sense is going to depend on the ratio of your house usage vs your HP usage.
So again the equation will vary property to property, person to person.
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It is a massive headache when trying to work out how to best cover the extra cost of the ASHP vs electricity rates and I am still learning everyday. Most likely I will leave it to the experts but for now I have ripple 900w wind farm coming online next year and another 500w solar later 2024. In the grand scheme of things I am so happy that governments gave an extra £2500 as that is equivalent to 7812kwh at 32p, my maths is not that good but that should be at least 31248kw of heat if SCOP of 4. Sorry, geek mode on or dream mode on lol
 
That’s the thing, those making the jump now with the £7500 grant will be laughing at those paying £11k in a few years once the money runs out.

Retrofitting one of these things isn’t going to get any cheaper. It’s not new technology, they sell hundreds of thousands, if not millions of these things a year, just not in the U.K.

For my quote, the actual cost of the heat pump itself makes up about 25% based on prices I’ve found online.
 
b0rn2sk8 said:
That’s the thing, those making the jump now with the £7500 grant will be laughing at those paying £11k in a few years once the money runs out.

Retrofitting one of these things isn’t going to get any cheaper. It’s not new technology, they sell hundreds of thousands, if not millions of these things a year, just not in the U.K.

For my quote, the actual cost of the heat pump itself makes up about 25% based on prices I’ve found online.
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I can't for my circumstances has I recently bought a new gas boiler a month ago and removed old hot water tank and relocated the boiler
 
200sols said:
Thing is most households can't afford £11k, support will have to be available for many years to come yet.
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I don’t disagree but that’s not what the government announced, they announced £450m to get the market going.

The expectation is that once the market gets going, prices will come down but I just don’t see it happening. Most of the work involved with a retrofit is just standard plumbing.

In my mind air to air makes a MUCH better retrofit platform but it’s taboo because it also does cooling and therefore isn’t ‘eco’ and isn’t in scope of the grants/support despite being more efficient and cheaper to install for most properties.
 
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You don’t ***need*** better insulation. More heat loss means you need a bigger system to compensate than a property with a lower heat loss. That’s no different to gas. If heat in is greater than heat out, the house will be warm.

If a gas boiler can heat it, a heat pump can heat it, the only difference is that a heat pump needs proportionally larger radiators (and associated pipework) because it operates at lower flow temperatures.

Insulation lowers running costs for gas and heat pumps, it should be done regardless of the heat source while taking care to also deal with ventilation needs. MVHR is the gold standard for all properties regardless of age.

Of course a house with better insulation means that in practice you’ll likely need less remedial work to install a heat pump.
 
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b0rn2sk8 said:
You don’t ***need*** better insulation. More heat loss means you need a bigger system to compensate than a property with a lower heat loss. That’s no different to gas. If heat in is greater than heat out, the house will be warm.

If a gas boiler can heat it, a heat pump can heat it, the only difference is that a heat pump needs proportionally larger radiators (and associated pipework) because it operates at lower flow temperatures.

Insulation lowers running costs for gas and heat pumps, it should be done regardless of the heat source while taking care to also deal with ventilation needs. MVHR is the gold standard for all properties regardless of age.

Of course a house with better insulation means that in practice you’ll likely need less remedial work to install a heat pump.
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The reason why you need good insulation is because heat pumps don't pump out as much heat as a gas boiler.

You also need larger radiators because of this.
 
Mercenary Keyboard Warrior said:
There will be days granted when they help.
But unless someone has specified a serious battery then its going to make naff all difference in the key months.
I think its highly unlikely that people who already have batteries will be having a spare 10+ kWh of storage

My average gas usage Dec-Feb was 40kWh a day, thats heating and water plus a small amount of gas hob
My average PV generation was 4.88kWh, thats a 5.6kw array west facing, which is about 4kw effective to south facing.

You need to really consider the marginal units added above your daily usage as opposed to the average cost if your being honest.
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Exactly this.
Same for us. We have solar PV plus a heat pump, but no battery because I can't see it making financial sense.
In winter our heat pump can use 25 kwh per day and total house usage can be >40 kwh.
We'd need a huge battery array to make it worthwhile. But we'd only use it's full capacity for a 2-3 months in the year. Plus we'd need a beefy inverter to charge up a large battery quickly enough during cheap tariff hours.
The ROI would be far longer than the life of the battery and inverter.
That said, I'd still like to build my own battery storage system sometime but more for the fun and interest rather than save money.
We have got a solar diverter to dump excess solar electricity into our water tank. I think this makes sense just because it's so cheap to install (cost me about £250). It may only save us 1 kwh per sunny day but my guess is we'll break even within 3-4 years.
 
jonneymendoza said:
OK cool thanks. Was it cheaper to run your heat pump vs a gas boiler for your usage during winter?
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We've halved our energy usage and cost by going from an LPG gas boiler plus electric heaters to heat our house, to installing solar PV and a heat pump plus UFH and insulating the roof, walls and floor.
Also the house used to still get chilly even with high fuel costs. Now it's comfortable.
If we'd kept the LPG boiler and still did everything else we still would have dramatically reduced our heating bills but I think with the ASHP+solar I think we save more.
 
jonneymendoza said:
The reason why you need good insulation is because heat pumps don't pump out as much heat as a gas boiler.

You also need larger radiators because of this.
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That's not how it works. If heat in is greater than heat out, the house will be warm, the heat source is literally irrelevant.

You can change zero about the insulation of a property, install a heat pump and it work. People say improve the fabric first because obviously reduces heat loss and its significantly cheaper than dropping £lol on a heat pump retrofit (not including grant) but you don't need to do it and you don't need to hit modern standards for insulation and airtightness.

Say you have a room (for arguments sake, its heat loss is 750W) which is heated by a 500mmx1000mm (0.5m2) type 11 radiator that puts out 800W at 70C. Now drop the flow temp 50C. At 50C, a type 11 only puts out 800W/m2 so a 500mmx1000mm radiator would only be putting out 400W which isn't enough. If you swapped it for a type 22 of the same size it would put out 750W which is exactly what's needed. A sensible person would probably install 600x10000 type 22 (900W) given the negligible price difference and should fit under a window to add a little headroom.

Its just physics at the end of the day.
 
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b0rn2sk8 said:
That's not how it works. If heat in is greater than heat out, the house will be warm, the heat source is literally irrelevant.

You can change zero about the insulation of a property, install a heat pump and it work. People say improve the fabric first because obviously reduces heat loss and its significantly cheaper than dropping £lol on a heat pump retrofit (not including grant) but you don't need to do it and you don't need to hit modern standards for insulation and airtightness.

Say you have a room (for arguments sake, its heat loss is 750W) which is heated by a 500mmx1000mm (0.5m2) type 11 radiator that puts out 800W at 70C. Now drop the flow temp 50C. At 50C, a type 11 only puts out 800W/m2 so a 500mmx1000mm radiator would only be putting out 400W which isn't enough. If you swapped it for a type 22 of the same size it would put out 750W which is exactly what's needed. A sensible person would probably install 600x10000 type 22 (900W) given the negligible price difference and should fit under a window to add a little headroom.

Its just physics at the end of the day.
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OK makes sense thanks
 
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