Heat Pumps: anyone have one/thought about it?

[darkgen]

Pfft. 10 years. I think the boiler here is 20 years old!

I'd be more than happy for it to survive another 10 years but even then my rationale would remain unchanged. I'm not going to be spend 10k+ retrofitting my house to support ASHP. Whatever the clowns in gov say right now; costs to support ASHP will remain prohibitive for decades to come.

 

[darkgen]

I had a quote and a conversation with the Octopus installers earlier this week.

The price was good, £6k (inc £5k grant). I know I need a lot of remedial work to the heating system because of what’s installed now. I’ve got is a 20 year old Range Powermax on a vented radiator loop (delivers mains pressure hot water).

It’s not actually that much more than getting what I have replaced with an unvented cylinder and gas boiler based on what my neighbour paid in 2018. A combi would be cheaper to install but you lose the mains pressure hot water and the ability to heat with solar.

From the conversation I managed to gleam a few things. They are targeting flow temperatures of 50C and SCOP of 300%. It will be cheaper to run than a gas boiler based on that efficiency and lifetime costs will be in your favour.

I’d not want to go any lower on the SCOP for it to work out against gas. When you have the survey, see if there are any additional quick wins they can do (extra charge no doubt) to bring the peak flow temp (50c) down and therefore the SCOP up.

I forgot to ask if they install weather compensation - it’s quite important for efficiency. The 50C flow temp will be based on a -2 outside temp and 21 internal temperature. When it’s not -2 or you are just heating to set back temps, you’ll want the system to automatically bring the flow temp down to stop it cycling (on, off, on, off etc).

I’m pretty close to pulling the trigger, I think I’d want to speak to some other installers first and see what they can do in terms of target efficiency and cost. If Octopus can do it for that price, I’m sure others can as well.

Hmm; trying to ascertain what is meant by vented radiator loop. My combi provides central heating with hot water (on demand), situated in loft which vents to roof.

Do you require radiators to be replaced?
Will the installers perform all additional pipework, which may or may not include pulling apart (and then fixing) floor-board / boxing / trunking work?
Will the install also cap the gas mains supply?

Cheers!

 

[Coran]

I'd be more than happy for it to survive another 10 years but even then my rationale would remain unchanged. I'm not going to be spend 10k+ retrofitting my house to support ASHP. Whatever the clowns in gov say right now; costs to support ASHP will remain prohibitive for decades to come.

I’m not so sure about the decades bit. Octopus are claiming their new heat pump (mentioned earlier in thread - see Octopus press release) will cost people from nothing (£5k BUS covers it) to around £3k for upgrades.

They’re restricting their market to simpler cases to begin with, so not reflective of wider costs in the market. However it shows that a reasonable proportion of the UK can switch away from greenhouse gas emitting boilers. Brings in the challenge of improving our green electricity production though.

 

[China Man]

If you’d like to look at real world examples, there are some UK based ones here: https://heatpumpmonitor.org/

Watch out for the data length column. You want a full year to see a true SCOP.

The equipment to log this level of detail is quite expensive so the people logging on that page are probably very keen and working hard to improve efficiency - so it’s likely to be a slightly skewed view.

Thanks for the link, I completely forgot I got emonpi which I monitor my solar with. I may have to but some mods to add ASHP data stream but I am a data geek so that would be interesting if I do go ahead with my install.

 

[darkgen]

I’m not so sure about the decades bit. Octopus are claiming their new heat pump (mentioned earlier in thread - see Octopus press release) will cost people from nothing (£5k BUS covers it) to around £3k for upgrades.

They’re restricting their market to simpler cases to begin with, so not reflective of wider costs in the market. However it shows that a reasonable proportion of the UK can switch away from greenhouse gas emitting boilers. Brings in the challenge of improving our green electricity production though.

As much as I would love to share your optimism, I just cannot envisage a time where ASHP will ever be cost effective over the long term unless gas supply costs becomes so egregious, households will have no choice. The government will not support the 5k grant in perpetuity so the retrofit (plus redecorating) costs aspect will then come in to sharp focus for households who choose to bin the gas boiler.

 

[fish]

I think that you have kind of answered you own question, gas prices etc will go up and become too high and unsustainable. How long this takes is anyone’s guess but given the age of the infrastructure and new estates not having gas I am not convinced it won’t be around a decade till the prices climb rapidly. The more people switch away the less there are to cover the cost associated with it. I know there are mix trials to add other gasses to the pipelines but how well will the older installs hold up to smaller gasses is anyone’s guess. The main thing I’m saying is no harm is getting a quote.

 

[Mercenary Keyboard Warrior]

A combi loses mains hot water pressure, are you sure about that?

The short answer is it depends. Low demand for hot water, single residence etc you probably won't notice any difference, the ability of the combi to supply demand is likely.
Larger households that may have multiple demands for hot water at the same time its pretty much a certainty the combi will struggle. (As would the system if all the hot water is used up and more is still demanded).

Its hardly a well kept secret that combis struggle with the higher end usage case.

With the losses from the stored water being so low now (the pressurised are super efficient at storage) the benefits of being able to heat with elec or gas (elec when its cheap/free etc such as solar or variable price tariffs kicking in) plus the low risk of supply issues if demand is up its becoming a bit of a no brainer to have a tank again.
When my boiler broke down the other winter I was very very glad of my 200 litres of hot water that still worked for the 2 days before by boiler got fixed. The lack of heating not so much. But at least being able to still take a hot shower offset some of the pain of the boiler breaking. Never go dressed so quickly as getting out of a hot shower into a cold house!

 

[Mercenary Keyboard Warrior]

I think that you have kind of answered you own question, gas prices etc will go up and become too high and unsustainable. How long this takes is anyone’s guess but given the age of the infrastructure and new estates not having gas I am not convinced it won’t be around a decade till the prices climb rapidly. The more people switch away the less there are to cover the cost associated with it. I know there are mix trials to add other gasses to the pipelines but how well will the older installs hold up to smaller gasses is anyone’s guess. The main thing I’m saying is no harm is getting a quote.

Not just that, but one of the key things in the future will IMO become a certainty, and thats time of use tariffs will be the norm.
Octopus have been giving me free elec for 2 hour spells as there is so much renewable generation locally. As the renewables peaks go up and up then old fixed cost all the time model will have to change (again IMO) to encourage people to use the energy for eg water heating when the large spikes hit.
Nothing encourages people like a good dose of carrot and stick.

As more and more people dump gas completely the grid charges, will have to be recovered from fewer and fewer people. That will push more to move and you get a self feeding circle of ever increasing charges on fewer and fewer people.
The big unknown really is timing. Are we talking 10 years or 30 years, but IMO, its coming and its inevitable.

 

[robj20]

The short answer is it depends. Low demand for hot water, single residence etc you probably won't notice any difference, the ability of the combi to supply demand is likely.
Larger households that may have multiple demands for hot water at the same time its pretty much a certainty the combi will struggle. (As would the system if all the hot water is used up and more is still demanded).

Its hardly a well kept secret that combis struggle with the higher end usage case.

With the losses from the stored water being so low now (the pressurised are super efficient at storage) the benefits of being able to heat with elec or gas (elec when its cheap/free etc such as solar or variable price tariffs kicking in) plus the low risk of supply issues if demand is up its becoming a bit of a no brainer to have a tank again.
When my boiler broke down the other winter I was very very glad of my 200 litres of hot water that still worked for the 2 days before by boiler got fixed. The lack of heating not so much. But at least being able to still take a hot shower offset some of the pain of the boiler breaking. Never go dressed so quickly as getting out of a hot shower into a cold house!

I don't have anywhere to put a tank anymore, so that wouldn't work for us.

 

[fish]

Not just that, but one of the key things in the future will IMO become a certainty, and thats time of use tariffs will be the norm.
Octopus have been giving me free elec for 2 hour spells as there is so much renewable generation locally. As the renewables peaks go up and up then old fixed cost all the time model will have to change (again IMO) to encourage people to use the energy for eg water heating when the large spikes hit.
Nothing encourages people like a good dose of carrot and stick.

As more and more people dump gas completely the grid charges, will have to be recovered from fewer and fewer people. That will push more to move and you get a self feeding circle of ever increasing charges on fewer and fewer people.
The big unknown really is timing. Are we talking 10 years or 30 years, but IMO, it’s coming and it’s inevitable.

Exactly this, the only thing is getting the time right to jump. The reason for this thread is that we may be forced to move due to circumstances now.

 

[200sols]

Pfft. 10 years. I think the boiler here is 20 years old!

Mine is 23 years old... not cost effective to replace, house is plumbed in microbore as well and changing that would be very very disruptive indeed. ASHP not workable for me right now.. air con probably better..

 

[jonneymendoza]

Right, so our boiler has decided to go to the scrap heap in the sky which has us in a rather large dilema. A replacement boiler is going to be around 3k (oh joy) or the alternative is go absolutely mad, get an air source heat pump and solar/battery array installed and hope for a payback of less than 20 years. This would effectively mean us removing gas from the property altogether and moving over to fully electric.

The question i have is, does anyone have an air source heatpump in an older house and whats ytour experience with them.

Cheers

Have a lil search here. I actually made a thread regarding heat pumps and came to the conclusion that right now it does not make any sense to get one until my property is well insulated externally and that I get bigger radiators and solar panels

 

[jonneymendoza]

Dup

 

[jonneymendoza]

Not just that, but one of the key things in the future will IMO become a certainty, and thats time of use tariffs will be the norm.
Octopus have been giving me free elec for 2 hour spells as there is so much renewable generation locally. As the renewables peaks go up and up then old fixed cost all the time model will have to change (again IMO) to encourage people to use the energy for eg water heating when the large spikes hit.
Nothing encourages people like a good dose of carrot and stick.

As more and more people dump gas completely the grid charges, will have to be recovered from fewer and fewer people. That will push more to move and you get a self feeding circle of ever increasing charges on fewer and fewer people.
The big unknown really is timing. Are we talking 10 years or 30 years, but IMO, its coming and its inevitable.

Yes but you can't just dump gas so easily without basically gutting out a property. Removing the gas pipes, insulating the property getting solar panels fitted, new pipe work, new storage on where your heat pump and storage hot water cylinder goes etc etc. And guess how much that will cost a family to do?

Forcing everyone to change heating system won't work and is not practical in the majority of houses in the UK

 

[jonneymendoza]

Have a look at the post I linked up above.
The one thing I would say is that if you have an old house, you may need to increase insulation, reduce drafts, and change radiators to get the benefits of an ASHP.
I don't think a straight swap between gas boiler and ASHP would work in an old house. ASHP heating is slow heating, so if the heat is lost as fast as it comes in you'll be cold.
For us, going from LPG boiler to ASHP with solar panels has been great. Our running costs are around half what they used to be.

Bet it will take u 10 years to break even though.. Maybe longer.

Solar panels last I checked ain't cheap to install and is quite expensive.

Materials for it is expensive and the labour plus scaffolding is also not cheap.

Did you already have insulated walls? Roof and ground floor insulation?

Did you also already have suitable radiator sizes and also a place to store the hot water cylinder tank?

 

[jonneymendoza]

I would say there’s no benefit to changing to an ASHP if you only factor in the cost. If you factor in the impact on the environment, there’s a huge benefit. It uses a third of the natural resources and that third can transition to being renewable over time.

Its all good saving the planet but only if you can still pay for your mortgage and food on your table for you and your family.

This is why forcing climate change on everyone won't work. This planet is doomed already and there are far worse off poorer people in other countries in the planet that can't go green at all.

And don't forget, only 2 percent? Of the whole entire human race is rich (rich as in able have a roof over your heat and put food on your table and have heating and lights on without much of a worry, not rich rich millionaires...)

Most of the planets human beings are way poorer then us and solar panels, electric vehicles and now air source heat pumps ain't free

 

[HungryHippos]

Hoping that the survey comes back with some good ideas on locations as I'd need to add a hot water tank etc, but as long as my pipework and existing radiators work with it without changing stuff, then I think I can install the system for roughly the quote they gave me.

I do agree that having to change all radiators and pipework would by itself probably make the entire thing not worth considering currently.

I'm fortunate that I already have a pretty well insulated house, with solar + battery (that I added myself).

 

[fish]

Have a lil search here. I actually made a thread regarding heat pumps and came to the conclusion that right now it does not make any sense to get one until my property is well insulated externally and that I get bigger radiators and solar panels

i did have a quick look and couldn't find much hence the new thread. I think the bigger issue with heat pumps is if you can stomach the cost in a long term house. currently we aren't looking to move and after 4 property rennovations woiuld like to staqy in a place for at least a decade. rooms have been insulated as they have been done and the heating system rads upgraded in the lasdt 5 years. Had we have known the boiler was so old it would have been changed also but thats on us for believing people.

 

[henry hoov3r]

i did have a quick look and couldn't find much hence the new thread. I think the bigger issue with heat pumps is if you can stomach the cost in a long term house. currently we aren't looking to move and after 4 property rennovations woiuld like to staqy in a place for at least a decade. rooms have been insulated as they have been done and the heating system rads upgraded in the lasdt 5 years. Had we have known the boiler was so old it would have been changed also but thats on us for believing people.

What boiler have you got in there at the moment?

 

[fish]

Worcester Bosch green star 18i