Air source heat pumps - a bit off putting, or is it just me?

[FolornLawn]

I was surprised to see how big and ugly they are.

This article shows a picture of one, and I wouldn't want it in my small garden. Also the report says people will need room for a boiler and a water cylinder.

I'm quite surprised at how negatively I feel about the new plans. There's something about having to remodel bits of my house and garden that feels like an imposition, when I happily recycle, use washable sanitary pads and kitchen roll, go without a tumble dryer etc. Is it just me?

Somebody asked up-thread about internal and external insulation, try here for very rough guidance.

www.vesma.com/tutorial/uvalue01/uvalue01.htm

@Coogee

To take the old house example, I’m not keen on the sounds of heat pumps at all and I think they could well spoil older properties like mine.

My house is a chocolate box type cottage but I don’t see why a heat pump would spoil it. My husband is very keen and seriously looking in to it. He is considering installing the pump machinery in a sound deadening enclosure so all that will be visible is a nondescript box that should be easy to disguise if we feel the need.

Are you going to put external cladding insulation on your chocolate box cottage? Or are you going down the route of internal insulation with the replastering and rewiring that goes with it?

Because I also have an older house with solid walls and can’t decide which is the least worse option.

@daisypond

I’m sure back in the day people thought there was no space for a gas boiler and it would spoil the look of the house. And people would have objected to ugly radiators cluttering up the rooms and the cost of installing them, when they were used to their gas or electric fire, and before that their open coal fire. Eventually, coal fires were banned and people were forced to make changes. Heat pumps are not much different - they will become commonplace and normal and people will look askance at houses with gas boilers and want to rip them out and replace them with an efficient heat pump. If that means bricking up huge walls of glass and bifold doors, that’s what they will do - and they’ll wonder at the folly of those who installed them.

Yes but not have to pay a fortune in the long run and for them to work efficiently.

They sound very dodgy to me at this point in time

Are you going to put external cladding insulation on your chocolate box cottage? Or are you going down the route of internal insulation with the replastering and rewiring that goes with it?

No intention to do either. We do have thick loft insulation and plan to replace the window panes with double glazed units.

Old houses need to breath and if it means spending a bit more on electricity to keep it warm, then so be it. I’m not convinced that it will be a problem though.

www.dailymail.co.uk/debate/article-10121865/JOHN-HUMPHRYS-heat-pump-left-cold-Im-hot-bothered-PM.html

John Humphreys isn't keen.

Yeah I saw that John Humphrey article earlier. Plus read a lot from people who fit them saying don't do it on older properties. It's all good saying that you don't think it'll be a problem but potentially an expensive mistake if it is. It's not just a case of spending more on electricity.... Some people can't get their houses above 15 degrees in the winter. I think I'll wait and see a bit longer.

I read that too. I was dissapointed that he didn’t give any details.

His house took a long time to warm up. So does ours with a 30 kW gas boiler. Pre covid we would spend a month away over Christmas and would have to turn on the heating four days before we we due to arrive home to allow the house to heat through. It has a huge thermal mass. Presumably, his house does too.

It's not just a case of spending more on electricity....

Of course it is. If one pump doesn’t work, we can run two in series.

It tends to be best to be one of the very last people to adopt new things so you are not the guinea pigs so I ould resist this stuff as long as possible. When y parents got gas central heating instead of fires when I was about 5 (which I remember) it was a huge improvement for obvious reasons - all that coal that had to be pushed into the side of the house down into the coal place, all the dirt and grime and lighting and cleaning of fires -it was step up. What is now proposed is a step backwards which is just a waste of money as the rest of the world won't be doing this so the UK is just choosing in effect to burn 1 trillion pounds pointless on this stuff. It will not be better. It will be much worse and more expensive.

Have to agree Xenia

Absolutely…..I’m sure technology will improve over the next ten years or so. Either better pumps or maybe hydrogen. So I will hold off for now.

@CovidCorvid it's unlikely that hydrogen is ever going to find much application in domestic settings.

I think some people are deliberately trying to find problems where there aren't any

As someone who went out and sought quotes to convert my house to a heat pump system I think there are a lot of smug virtue signalers insisting that what worked for them must work for everyone else and pretending that works listed at tens of thousands of pounds are a minor detail.

Your lifestyle may treat those sums as trivial, for most people it is anything but.

Rather like the "brick up your windows and sleep next to an airpump" brigade on this thread. I remember my parents putting in central heating - nobody carped about fitting radiators in because it meant warmth (and in fact they went against existing walls - we didn't brick up windows to fit them). People with very small accommodation often didn't have cylinder based heating because they lacked the space and money - they went without.

If any of the green virtue signalers on this thread think they are really making the case by dismissing the real and practical problems people face then think again - you are entrenching opposing views.

@C8H10N4O2

I think some people are deliberately trying to find problems where there aren't any

As someone who went out and sought quotes to convert my house to a heat pump system I think there are a lot of smug virtue signalers insisting that what worked for them must work for everyone else and pretending that works listed at tens of thousands of pounds are a minor detail.

Your lifestyle may treat those sums as trivial, for most people it is anything but.

Rather like the "brick up your windows and sleep next to an airpump" brigade on this thread. I remember my parents putting in central heating - nobody carped about fitting radiators in because it meant warmth (and in fact they went against existing walls - we didn't brick up windows to fit them). People with very small accommodation often didn't have cylinder based heating because they lacked the space and money - they went without.

If any of the green virtue signalers on this thread think they are really making the case by dismissing the real and practical problems people face then think again - you are entrenching opposing views.

What you have quoted was in response to someone complaining that having slightly larger radiators fitted would lead to them needing to replaster and redecorate their entire house. Which is ridiculously melodramatic.

@C8H10N4O2 I don't see anyone virtue signalling, but there are a lot of misconceptions.

ASHPs don't have to be physically attached to house, they can be at the bottom of the garden if necessary.

ASHPs at least modern or well maintained ones make no more noise than a combustion boiler.

ASHPs don't require your radiators to be upgraded, there are high temperature models that can be plumbed into your existing system. I'm sure plumbing contractors are aware of this but they are probably trying to upsell.

ASHPs do need to be properly specified, if your old boiler is 30kW there is no way a 16kW ASHP is going to work.

At the end of the day combustion boilers are going to be phased out. It will then be to individual home owners whether they want direct heating or a heat pump which 3x as efficient.

If we all insulated our homes as much as possible, wherever possible, and used the most efficient means of heating our homes and DHW the switch to clean energy using the existing electrical grid is totally doable.

ASHPs do need to be properly specified, if your old boiler is 30kW there is no way a 16kW ASHP is going to work.

You could run it for twice as long, the heat output would be the same. I agree that it might not work in every situation. Our house has an extremely high thermal mass, some of the internal walls are two feet thick, so it might work for us and something we are investigating.

@Coogee

ASHPs do need to be properly specified, if your old boiler is 30kW there is no way a 16kW ASHP is going to work.

You could run it for twice as long, the heat output would be the same. I agree that it might not work in every situation. Our house has an extremely high thermal mass, some of the internal walls are two feet thick, so it might work for us and something we are investigating.

We were told that you should always 'round up' when calculating for and installing the heat pump. It is when the heat pump is straining and working at its limit that you get major problems with inefficiency, which is also why you programme the system differently to other Central heating systems, in order that you never have any really big drops in temperature and corresponding big climbs in temperature.

The research we read stated that where people are disappointed in their ashp systems it is down to one (or more) of the following...
Too small a heat pump
Too small radiators
Lack of insulation
Expecting to be able to set their thermostat at 23C+

So for those not considering getting an ASHP just yet, they should really focus on improving insulation and also any time they replace a radiator consider getting a slightly bigger one in preparation for the change over to a heat pump system.

It is when the heat pump is straining and working at its limit that you get major problems with inefficiency, which is also why you programme the system differently to other Central heating systems, in order that you never have any really big drops in temperature and corresponding big climbs in temperature.

Exactly, so instead of running our gas boiler six hours a day at 30 kW, we would run the 16 kW heat pump at half capacity, 8 kW, for twenty four hours a day using the mass of the building and a hot water thermal store as a buffer to smooth out any irregularities. Possibly adding thermal solar panels into the mix.

Our thermostat is set at 18.

Bold fail!

@Coogee it doesn't work quite like that. If you had a 100kW heat pump that could only supply water at 20C you could heat a small village very efficiently provided every square metre was covered in radiators.

You need to consider more than just power rating, heat transfer etc matters just as much.

If you need higher temperatures to get the heat transfer up models such as the Daiken HT which is effectively two heat pumps in series will do the job for you.

You need to consider more than just power rating, heat transfer etc matters just as much.

I have. The amount of heat transferred in to the house is maintained by running the pump 24 hours rather than six.

A one metre square radiator will transfer the same amount of heat as a ten metre square radiator if it is run for ten times as long.

@Coogee yeah but heat and temperature are different things.

@Coogee

You need to consider more than just power rating, heat transfer etc matters just as much.

I have. The amount of heat transferred in to the house is maintained by running the pump 24 hours rather than six.

A one metre square radiator will transfer the same amount of heat as a ten metre square radiator if it is run for ten times as long.

But surely per hour the small radiator would only kick out a tenth of the heat the bigger one would? So the room might still be cold?

Interesting article here on hydrogen technology. www.theguardian.com/science/2020/mar/21/is-hydrogen-the-solution-to-net-zero-home-heating

Apparently Worcester bosch have already got a working hydrogen boiler and the existing gas network could be fairly easily converted. www.homebuilding.co.uk/news/hydrogen-heating

I also read something years ago which said that there is a good change that hydrogen cars will eventually take over from electric cars.

But surely per hour the small radiator would only kick out a tenth of the heat the bigger one would? So the room might still be cold?

It might if you are losing heat faster than the radiator can put it in, yes. However, if the masonry in the house is acting like a giant storage heater it will also be emitting heat to supplement the radiators. That’s the theory anyway.