Air source heat pumps in the news again

[jim843]

ASHP's will work if installed correctly in any property. As you rightly point out the pipe sizing and insulation is critical to that.

In your opinion would a heat pump work in my home (see above for more detail).

Built around 1890. Solid walls to front and rear. High ceilings. Draughty!

 

[pewe]

ASHP's will work if installed correctly in any property. will have the system working but it will cost a fortune to run if pipework isn't upgraded. This is good technology.

What would pipework have to be upgraded to in order to work efficiently?
For example we have 10 radiators (about 60,000 BTU) on a 15mm piped circuit run from a gas combi boiler.
Someone tried to talk us into installing an electric combi, with solar panels to run it in the daytime and batteries to run it in the evening.
From comments I've read whilst trying to do some research, it appears that at a cost of over £12,000 plus installation it would not be a wise expenditure without upgrading insulation, and the size of all the radiators first.

 

[gmartine]

^^^ I'd like to see a working example of that and interrogate the owners, you'd need a decent array of solar panels to do everything as well as a large battery pack or it'll cost you a fortune to run as well.

I watched this a while ago and can't remember the numbers but in principle it utilises many of the same things you may need cept we don't know how he heats his house.

 

[John.g]

I know the thread title is ASHPs but there is no mention of storage heaters which are powered from renewable energy, one would think that they could play some even small part.
Some of them like the Dimplex Quantum can actually retain heat unlike the old ones where it leaked away during the day.

 

[Ric2013]

What would pipework have to be upgraded to in order to work efficiently?
For example we have 10 radiators (about 60,000 BTU) on a 15mm piped circuit run from a gas combi boiler.
Someone tried to talk us into installing an electric combi, with solar panels to run it in the daytime and batteries to run it in the evening.[....]

Okay. Electric combi/PV combination and ASHP are different. The ASHP will work better at low flow temperatures, so you need thicker pipes and bigger radiators to give the same heat output with cooler water. With PV and electric combi, you have no particular need to reduce the flow temperature (in a nutshell).

I hope I'm not being political in questioning the technical validity of proposed solutions. I'm trying not to be, but I suppose we all have our biases. There is a sense in which renewables will push the output of the grid up at certain times of day and conventional power stations (especially nukes) are not easy to shut down and restart quickly, plus they may be running idle to give the grid some excess capacity for cloudy and calm moments, advert breaks (kettles!), etc. So may as well run ASHP under such conditions on houses where they are suited, and retrofitted improved insulation etc to existing stock may make a lot of it suited to ASHP. Not all of it - I agree!

What's the deal when it comes to high RH, however, as is typical in the British climate? The above charts ignore R.H. which can be 80 - 90% in the U.K.. My understanding of the problems C.A.T. (West Wales) had with its heat pump was that it (obviously) increased the R.H. of the outside air to dewpoint where it hit the evaporator and then, since the evaporator surface was below 0°C, frost formed instead of the condensate just dripping off. At which point, either they needed to use a defrost resistive electric heater coil to defrost the evaporator, or the ASHP no longer worked. This, at C.A.T., was dropping the C.O.P. to below 1. Is there a way of avoiding this? My feeling is that there probably is not, and that the sensible thing to do in this case is to avoid installing a defrost coil and switch to conventional resistive electric heating (or gas etc) in such circumstances, reserving the A.S.H.P to the warmer months of the heating season. If there is a better alternative, I would genuinely like to hear it. I would be open to fitting an ASHP even on my own house if I thought it would work well.

 

[Jones82]

I've started insulating where every I can and advising customers to do the same, especially when floors are up or work been carried out. I've also started oversizing radiators and pipework, another advantage to this is the gas boiler flow temperature can be turned down, increasing efficiency. I don't want to get political or start pointing fingers but the ashp news story that I heard was woefully light on the real details and if we are to belive the rest of the media, time is running out when it comes to climate change.

I do feel its bad journalism and bad government to gloss over all these key details with a "£5k grant for ASHP"

I think the truth is a £5k grant makes money for someone somewhere, where as insulating britain and seriously addressing our move to renewables is going to cost massive amounts of money not make it.

I'm also concerned that many an old vunerable customer is going to be misold an air source heat pump, only to find they've spent way too much money on a poor installation.

 

[cjg]

old vunerable customer will be ripped off by so called hp installers, every tom dick and harry will be starting to sell and installand rip the govment off, then close down. when the sh~t hits the fan,
and now we are all on leccy there will be power cuts no cooking, heating, cars charge, lighting.
and best of all the price will double or more how f in daft are we gettting

 

[John.g]

But eventually of course, NUCLEAR power will be the new saviour.

 

[ShaunCorbs]

Insulation is key let’s say you have a 500w load on a heat pump you need a 2.0m x 0.6 k2 rad

Gas boiler 6x6 k2

 

[brum]

I'm getting so sick of the media and tories plugging ashp's like they are the solution to all our heating needs.

Latest news today, £5k grant towards the cost of replacing a gas boiler with an ashp. What a joke.

Every ashp system I've worked on and installed runs the heating at 40 degrees, great for a new build with fantastic insulation and underfloor heating but just simply wouldn't work in most of the houses in England.

Why is this never mentioned in the media?

Air source should be the last thing we do not the first, the first should be insulation and upsizing pipework.

Just think of all them new builds, built in the last 30 years with microbore pipework, some barely run on gas boilers nevermind air source.

It makes me wonder what other things the tories pretend to know what they are talking about

I think one of Boris' mates manufactures ashp's....

you cant blame the tories ffs

 

[Jones82]

you cant blame the tories ffs

I don't want to get into a political argument but the tories have been in power for 11 years next year.

Their current energy policy is woefully lacking leadership and ambition.

In my opnion they are the party of self interest and corruption and I've seen little to dissuede me otherwise. That is not to say labour are any better.

Here's a good example, did you know that privatised water companies have paid £54 billion to their shareholders since 1991? Imagine if that was money was reinvested in our infrastructure instead of making rich people richer.

How much do you think the energy companies are making?

Honest prediction? We are going to see a climate incident on a scale not seen in human history which will force the entire global population to take this more seriously.

Thats my opinion and I hope I'm wrong

 

[SimonG]

I dont want to get into a political argument but.

Should have left it with the first statement.

It's a plumbing forum not a government bashing forum.

 

[Jones82]

Ok I apologise but it was a direct question how is it the tories fault.

 

[Sparkgap]

Caveat Emptor!!! A few years ago I had a commercial installation at a community centre. UFH, ASHP, total heat losses for the building about 70kW. ASHP manufacturer quoted for a unit, sparkies checked loading for new substation transformer which was being replaced with another which was already on site and which would give sufficient spare capacity for future improvements. I step up and throw big spanner in the works: what was the ASHP output for the client's design conditions (-4C outside temp)? Manufacturer comes back with quote for 100kW unit and spare substation capacity virtually disappears! Always check outputs at the design conditions, not what the manufacturers test them at!

Currently have a project going on: existing 12 year old designer house, UFH, acres of glass. Major extension being built (about 90% floor area increase!) also with UFH and a/c being fitted to new and existing rooms as amount of glass is causing issues with overheating. VRV system going in so that in summer a/c can dump heat directly into HWS system and in effect give free hot water. Client is not short of a bob or three but still complaining about running costs (currently £15-20k/yr for three people!!!).

Talking of running costs, latest figures from Nottingham Energy Partnership give ASHP (assumed 270% efficiency, electric at 22.2p/kWh) at 8.22p/kWh and mains gas (assumed 90% efficiency) at 4.88p/kWh. Why do I want to change my gas boiler for something which is going to cost me twice as much (even assuming I had a suitable heating system for it)?

 

[BobbyJoe]

Hi everyone,

I bought my small flat (built late 60s) about 2 years ago and got a new gas combi boiler as well as other upgrades as the flat needed fixing up.
My question is, is it mandatory by the government to get air source heat pump installed? I couldn't afford it even with the grant help but am feeling a little worried about it as I am happy with hot water and heating in my flat and don't want to or be forced to change it.

Also for those who live in council let properties do they have any rights to refuse ASHP or does the council over rule this change?

Any advice would be really appreciated thank you.

 

[cjg]

firstly, no, gas boilers will be around for a long time yet, if they try to push it then its a complete new heat system as all the pipe work will have to be upgraded bigger rads, ect, ashp,s will not work unless you have first class insluation ect,
and theres talk of hydroden boilers comeing, so no pannic,..

 

[Phill K]

Like CJ has said, it isn’t mandatory. Just another case for why you should never believe what they say on the “lies box” in the corner of the front room.
Propaganda and scare tactics being monopolised by some very unscrupulous companies.
Like smart meters, no mandate that you must have them.

Company I work for is already sending out it’s boilers ready for the hydrogen change over, Cadent have been busy digging every street in the country upon preparation for it.

One word of advice though, if you are getting a new boiler, get it done before June, energy laws change and it’s going to be a headache for installers to say the least

 

[king of pipes]

Hi everyone,

I bought my small flat (built late 60s) about 2 years ago and got a new gas combi boiler as well as other upgrades as the flat needed fixing up.
My question is, is it mandatory by the government to get air source heat pump installed? I couldn't afford it even with the grant help but am feeling a little worried about it as I am happy with hot water and heating in my flat and don't want to or be forced to change it.

Also for those who live in council let properties do they have any rights to refuse ASHP or does the council over rule this change?

Any advice would be really appreciated thank you.

You won't be forced to change anything so please don't worry gas boilers will be with us for the for seeable future and are still being installed, there could be a few changes coming but it's nothing to consern yourself with and will be brought in slowly. Regards kop

 

[gmartine]

Electricity is going to be over 30p per kw/h after Autumn's planned cap increase, hold tight.

 

[Ric2013]

One word of advice though, if you are getting a new boiler, get it done before June, energy laws change and it’s going to be a headache for installers to say the least

That's worth knowing. Still catching up on back copies of "Installer" so not heard of this. Had a quick look online. The Baxi website explains it simply, but what it is suggesting the law requires seems to me to be no more than what I would deem common sense. What problems do you expect are going to crop up that the idiots in Whitehall haven't forseen?

 

[Murdoch]

Imho only really modern builds can justify ASHP technology

 

[gmartine]

According to Heat Geek if you can run your flow temp at 55 deg C when it's cold outside (-2?) and your comfortable then a dwelling should be compatible with an ASHP without any further alterations like increased pipe size or emitters.

Seems like a reasonable rule of thumb for Southerners as we barely get a frost down here.

 

[John.g]

A 15kw unit will achieve this, if 9.5kw is sufficient to keep your house warm but at a increased cost of course as the COP will be ~ 2.1.

 

[Last Plumber]

According to Heat Geek if you can run your flow temp at 55 deg C when it's cold outside (-2?) and your comfortable then a dwelling should be compatible with an ASHP without any further alterations like increased pipe size or emitters.

Seems like a reasonable rule of thumb for Southerners as we barely get a frost down here.

If you can do it with a DT (flow & Ret diff) of 5 degree C then I suppose it could be a rule of thumb.

 

[John.g]

If 55C/50C (flow/return) is OK and if one wanted to get the maximum COP from the heat pump it would need rads upsized by a factor of almost 3.5 (3.46) to allow 35C/30C (flow/return).

 

[gmartine]

Simon here (Urban Plumber) put in a ASHP in what looks like a period house (with Heat Geek), they clearly uprated the insulation from underneath but the size of those emitters??!!!

 

[Jonnyo]

Caveat Emptor!!! A few years ago I had a commercial installation at a community centre. UFH, ASHP, total heat losses for the building about 70kW. ASHP manufacturer quoted for a unit, sparkies checked loading for new substation transformer which was being replaced with another which was already on site and which would give sufficient spare capacity for future improvements. I step up and throw big spanner in the works: what was the ASHP output for the client's design conditions (-4C outside temp)? Manufacturer comes back with quote for 100kW unit and spare substation capacity virtually disappears! Always check outputs at the design conditions, not what the manufacturers test them at!

Currently have a project going on: existing 12 year old designer house, UFH, acres of glass. Major extension being built (about 90% floor area increase!) also with UFH and a/c being fitted to new and existing rooms as amount of glass is causing issues with overheating. VRV system going in so that in summer a/c can dump heat directly into HWS system and in effect give free hot water. Client is not short of a bob or three but still complaining about running costs (currently £15-20k/yr for three people!!!).

Talking of running costs, latest figures from Nottingham Energy Partnership give ASHP (assumed 270% efficiency, electric at 22.2p/kWh) at 8.22p/kWh and mains gas (assumed 90% efficiency) at 4.88p/kWh. Why do I want to change my gas boiler for something which is going to cost me twice as much (even assuming I had a suitable heating system for it)?

I work for a company that provides advice on energy performance, air tightness and acoustic design of buildings. I can't wait for the law suits to start over covid. We have seen this on a small scale with the failed green initiative that Cameron started. We had clients that were literally freezing in the winter with an ASHP and were paying extra for electric rads. The problem is that ASHP only work in airtight x we'll insulated homes otherwise they cost you a fortune. Unless you like pouring money down the toilet you have to run your dad's at a lower temperature over a longer period. The problem with this is ; 1 - your rads release less radient heat so you don't feel it
2- you rads release less convective heat
3- in a poorly insulated home your room can feel very cold because of the temperature gradient in the room floor to ceiling. When you use gas you can crank the temp high easily but getting an ASHP to increase the water temp up to gas temps you will start to see returns close to 1:1. Not 300% or the nonsense the gov keep saying. You would be better off heating up a thermal store on encomy 7 with elec then using that in the day. Than spending loads on and ASHP.
I really hope the people selling these ASHP do some basic checks before installing. Modern windows, wall insulation, roof insulation, airtightness decent. Otherwise I'm going to be very busy.

 

[Jonnyo]

I work for a company that provides advice on energy performance, air tightness and acoustic design of buildings. I can't wait for the law suits to start over covid. We have seen this on a small scale with the failed green initiative that Cameron started. We had clients that were literally freezing in the winter with an ASHP and were paying extra for electric rads. The problem is that ASHP only work in airtight x we'll insulated homes otherwise they cost you a fortune. Unless you like pouring money down the toilet you have to run your dad's at a lower temperature over a longer period. The problem with this is ; 1 - your rads release less radient heat so you don't feel it
2- you rads release less convective heat
3- in a poorly insulated home your room can feel very cold because of the temperature gradient in the room floor to ceiling. When you use gas you can crank the temp high easily but getting an ASHP to increase the water temp up to gas temps you will start to see returns close to 1:1. Not 300% or the nonsense the gov keep saying. You would be better off heating up a thermal store on encomy 7 with elec then using that in the day. Than spending loads on and ASHP.
I really hope the people selling these ASHP do some basic checks before installing. Modern windows, wall insulation, roof insulation, airtightness decent. Otherwise I'm going to be very busy.

Oh yeah and ASHP don't sound noisy in towns and cities.
Put one on a house in a quiet village and have it fire up at 4am and watch the sparks fly. It's hilarious....

 

[gmartine]

The early-ish adopters or first through the door will always get bloodied with poor or inappropriate design as installers jump on the band wagon. It'll settle eventually, the tech will get cheaper with installers and system design better (hopefully) and clients more knowledgable.

 

[ShaunCorbs]

I agree with some of your comments jon but others depends on installer

Normally have problems when a heat pump is just stuck on a boiler replacement eg existing rads etc

The rads need to be correctly sized for a heat pump system

Agree east way is to see where the insulation gaps and heat leaks are

These days with the new ones there whisper quiet

 

[king of pipes]

Oh yeah and ASHP don't sound noisy in towns and cities.
Put one on a house in a quiet village and have it fire up at 4am and watch the sparks fly. It's hilarious....

Agreed mate they may start off acceptable but definitely get worse with time , get a whole row of properties with em and you know about it .

 

[Jonnyo]

Agreed mate they may start off acceptable but definitely get worse with time , get a whole row of properties with em and you know about it .

Yeah we do noise surveys for planning and a developer had 10 houses back to back in a rural town with ashp in each garden. These are modern mitsubishi units. It's horrendous. All you can hear is the noise of the heat pumps clicking and humming. Ticking time bomb. Going to be worse than the diesel scandal in my opinion. I can do you a noise map if you want to see.

 

[Jim09876]

Just watched Allen Hart on YouTube having an ASHP installed at his home…Oof quite a rig! Allen cracks me up, worth a watch. Seems like way too many components not to be a headache moving forward.

 

[gmartine]

Just watched Allen Hart on YouTube having an ASHP installed at his home…Oof quite a rig! Allen cracks me up, worth a watch. Seems like way too many components not to be a headache moving forward.

Yeah but was big Al factored into the heat loss calcs?

 

[Jim09876]

Yeah but was big Al factored into the heat loss calcs?

He has a slow metabolism, what’s a brother gonna do.

When he cracks open that control unit 1:32 “what’s inside there then”

What’s not inside here Allen…