Looks like the party is over....

[SteamyTea]

16 minutes ago, Beelbeebub said:

was wondering if installing A2A alongside the existing gas heating and DHW is a good step to moving off gas. 

Basically what @JohnMo did, but with an A2WHP.

 

[SimonD]

https://www.gov.uk/government/news/discounts-for-families-to-keep-warm-in-winter-and-cool-in-summer

[Crofter]

33 minutes ago, -rick- said:

Personally, I'm not a fan of air based heating (or cooling) systems. I've never experienced one where I'm not disturbed by the noise when sleeping and I can see that pushing a lot of people to maybe install a system, use it partially but also keep relying on the quiet, hydronic, system much more than any government funded scheme would like. But I think it's worth trying, Americans tend to have air based systems and they don't generally see them as an issue.

I installed A2A last year and I'm very happy with it. The main unit sits under the floor with 200mm insulated ducting running to the larger rooms, and 150mm to bedrooms. The outlets are at floor level (plinth in the kitchen, just above skirting elsewhere). It's inaudible unless you put your ear right up to it.

The MVHR I fitted makes more noise.

[Dillsue]

1 hour ago, -rick- said:

 

Exactly, they are contracted to be on even if the power isn't needed. Changes are being made to eliminate the need for them in the not too distant future.

Not sure about that. See https://assets.publishing.service.gov.uk/media/675c0ca798302e574b915336/eep-report-2023-2050.pdf figure 4.1

[sharpener]

6 hours ago, -rick- said:

The gas was being burnt as a lot of renewables don't have grid forming/peaker capability. This is apparently being fixed by changing inverter programming and the deployment of more batteries (to replace a lot of peaker use).

 

Don't know why this is still a problem. When I worked in the wind turbine business 20 yrs ago it was already being introduced into the German Grid Code. I think there is a lot of good old mechanical inertia in a 10MW wind turbine.

 

  

1 hour ago, Beelbeebub said:

There are some HP systems that are entirely self contained and just require a pair of 150mm inlet/outlet ducts.

 

Yes but not practical for a whole-house system, we looked at this and the duct cross section was ?5x larger than just for MVHR so not practical if you want it to be virtually inaudible.

 

[-rick-]

13 minutes ago, Dillsue said:

Not sure about that. See https://assets.publishing.service.gov.uk/media/675c0ca798302e574b915336/eep-report-2023-2050.pdf figure 4.1

 

Interesting document. Firstly, want to make clear that my comments earlier are in relation to summer generation offsetting any additional cooling load caused by this policy change. I've not been thinking about winter generation at all though not sure that makes much difference for our conversation.

 

Secondly, the document shows significant reductions up to 2030, which again aligns with my comments. Beyond that I'm surprised by their predictions but also note that they are basing their graphs on agreed plans. It's inevitable that more distant renewable projects haven't yet been approved as most renewable projects are relatively quick to implement. Nuclear being the only real long term projects that might show up for 2040 predictions at this time.

[JohnMo]

2 hours ago, Beelbeebub said:

I was wondering if installing A2A alongside the existing gas heating and DHW is a good step to moving off gas. 

It's doable and works. Ran the gas boiler hydraulically separate via a large 40 plate PHE.  Control was outside the heat pump, so heat pump and boiler ran their own control. I had mine set to do gas at about 5 degs when defrosts start to happen. So at 5 degs when the compressor cycled the flow temp was low enough for the gas boiler to step in.  From that point the the gas boiler ran.  I did hybrid DHW all the time, so 210L cylinder with a max flow temp of 60 from the boiler, with a very low ramp rate set in the boiler. Heated cylinder in 20 to 30 mins. During the cylinder heating the ASHP and gas boiler would slowly ramp up together.

 

Downside on any decent electric tariff you have a cost penalty - running costs are lower even at cold outside temp, its close to zero all day today, so in the defrost zone and average CoP including DHW is 3.4, paying 14.33p per kWh, is still only 4.2p per kWh.  Yesterday would have been an all gas day on the hybrid system and the costs would have been about double compared heat pump (on Cosy and battery). Gas I assume is about 7p and you have a standing charge to pay.  So no longer have gas connected - just isn't worth it.

[Beelbeebub]

I would say the leveling off of the renewables after 2030 and slow rise of Gas & imports thereafter may be an artifact of the "horizon" for renewables onky extending out that far and then making the conservative assumption that nothing is added after that therefore the forecast demand increace will be met by thr default of gas and imports. 

 

I suspect that leveling off exists in earlier versions and will exist in future ones. 

 

I can't see a physical reason why that growth would plateau so abruptly. Slow maybe but just suddenly stop? 

[Beelbeebub]

4 minutes ago, JohnMo said:

It's doable and works...

 

 

This seems like a good path because it removes the twin doubts about HPs - that it might not be able to keep you warm and that it might cost more than gas over the year. 

 

Having the original system in place is very much the best of both worlds. The user k ow that - at worst - they will have their original system performance and cost.

 

The only disadvantage with this approach with A2W is that it has to share the emitter with the orginal system and if they are undersized the HP won't perform. 

 

A2A does sidestep this issue by having its own emitters, but has the downside of not providing DHW.

 

Both approaches have their benefits but neither are brig supported under the current system which mandates removing the old system - making for a much bigger leap of faith. 

[-rick-]

Just now, Beelbeebub said:

Both approaches have their benefits but neither are brig supported under the current system which mandates removing the old system - making for a much bigger leap of faith. 

 

Nothing in the doc that Simon posted suggests that the new A2A element requires removal or disabling of the old system. To me that seems like one of the biggest changes.

 

In the end I suspect this change if stands as is likely means almost everyone just installs new A2A and uses the cooling but continues to use gas in winter (possibly less). Not sure how MCS will work with A2A stuff either. Most of the existing MCS contractor base is not f-gas and don't think there is much crossover to A/C installers.

[Beelbeebub]

It does seem, in hindsight, that a better approach would have been to allow the old system to be left in place and provide grants for fitting a HP as a hybrid/piggyback system much as JohnMo did. 

 

Then for (say) £750 you could get a HP fitted to the side of your house and a box inside to connect it to the existing system. If that box controlled the HP and boiler (the boiler often being a simple on/off switch) it could run each system depending on outside air temp.  Over time thr owner would see the HP system kept them warm and was cheaper most of the time. Maybe upgrading the odd radiator every now and again would improve things until one day the boiler packed up and was never replaced 

[JamesPa]

6 minutes ago, Beelbeebub said:

 

Both approaches have their benefits but neither are brig supported under the current system which mandates removing the old system - making for a much bigger leap of faith. 

Hmm

 

Not sure about grants if old system is left in place.  Obvious thing to do is take the grant, get the system fitted, then sell it almost new.  Perfect opportunity for both organised crime and small time scammers.

 

It would certainly need rigorous follow up and significant easy to apply penalties to be even reasonably proof against the slime bags in our society.

Edited 20 hours ago by JamesPa

[Beelbeebub]

1 minute ago, -rick- said:

 

Nothing in the doc that Simon posted suggests that the new A2A element requires removal or disabling of the old system. To me that seems like one of the biggest changes.

 

In the end I suspect this change if stands as is likely means almost everyone just installs new A2A and uses the cooling but continues to use gas in winter (possibly less). Not sure how MCS will work with A2A stuff either. Most of the existing MCS contractor base is not f-gas and don't think there is much crossover to A/C installers.

With the prevalence of smart meters now, it will be alot easier to see which system is cheaper to run. I can imagine householders running with thr A2A, the maybe switching to gas every now and again and looking at the costs at the end of the day and switching back to A2A (or not). Over time they would gain confidence and experience as to which days are worth switching to gas. 

 

As I said, hopefully at some point the gas boiler woikd pack up and they'd decide it wasn't worth fixing. 

[-rick-]

Just now, Beelbeebub said:

With the prevalence of smart meters now, it will be alot easier to see which system is cheaper to run. I can imagine householders running with thr A2A, the maybe switching to gas every now and again and looking at the costs at the end of the day and switching back to A2A (or not). Over time they would gain confidence and experience as to which days are worth switching to gas. 

 

I don't think most people put anywhere near that much thought into their systems. We on this forum are not representative.

 

Just now, Beelbeebub said:

As I said, hopefully at some point the gas boiler woikd pack up and they'd decide it wasn't worth fixing. 

 

I can see this happening, but not because the bulk of people have analysed the costs but through inertia. ie, "the boilers broken, lets just use the AC for now and decide what to do with the boiler later". They'll stick on the immersion for hot water and then forget about it.

[Beelbeebub]

5 minutes ago, JamesPa said:

Hmm

 

Not sure about grants if old system is left in place.  Obvious thing to do is take the grant, get the system fitted, then sell it almost new.  Perfect opportunity for both organised crime and small time scammers.

 

It would certainly need rigorous follow up and significant easy to apply penalties to be even reasonably proof against the slime bags in our society.

But why would you buy a 2nd hand unit when you could get a new one for free via the grant?

 

And, sure a householder could do that but then they would have used their grant and wouldn't have any system. 

 

Removing an A2A unit intact is nearly as big a job as installing one in the first place. 

[-rick-]

Just now, Beelbeebub said:

But why would you buy a 2nd hand unit when you could get a new one for free via the grant?

 

The doc suggests a £2500 govt contribution to an overall £4500 cost so not free, just discounted. Bet their require MCS certification to do the install though so there goes your saving!

[Beelbeebub]

1 minute ago, -rick- said:

I don't think most people put anywhere near that much thought into their systems. We on this forum are not representative.

True enough. 

 

2 minutes ago, -rick- said:

I can see this happening, but not because the bulk of people have analysed the costs but through inertia. ie, "the boilers broken, lets just use the AC for now and decide what to do with the boiler later". They'll stick on the immersion for hot water and then forget about it.

That's a win anyway.

 

Switching the country to Heatpumps that can perform better than 2.5 over the winter season reduces our gas consumption even if we have to build some more gas plants. 

[Beelbeebub]

1 minute ago, -rick- said:

 

The doc suggests a £2500 govt contribution to an overall £4500 cost so not free, just discounted. Bet their require MCS certification to do the install though so there goes your saving!

The whole grant situation, especially with the closed shop MCS, invites grant harvesting. 

 

I still maintain using the subsidy to subsidise the heating costs of the HP system to guarentee a HP is always cheaper than gas would be a better way forward 

[JamesPa]

19 minutes ago, Beelbeebub said:

But why would you buy a 2nd hand unit when you could get a new one for free via the grant?

 

And, sure a householder could do that but then they would have used their grant and wouldn't have any system. 

 

Removing an A2A unit intact is nearly as big a job as installing one in the first place. 

Who says you would even fit it?  If you are allowed to retain your existing system then all that needs to happen is that the new unit is delivered to your house.  Then you can sell it on and, unless there are backup checks, nobody is the wiser.  And dont imagine that the removal (if it were fitted) would conform to f-gas regulations, snip the pipework, allow the gas to escape, unscrew 4 screws, bit of polyfilla, job done nothing spent.  Sell it wholesale, abroad or wherever, there is always a market!

 

Im assuming, I accept, that people are crooked, but the fact is that a proportion are!  We have almost the whole political class running round like headless chickens over only a few 10s of thousand of illegal migrants shipped around in deadly conditions by a bunch of crooks to evidence that!

Edited 20 hours ago by JamesPa

[Beelbeebub]

Sadly, people will always try to diddle the system, whether it be a."free" air conditioner or a £120 million contract for faulty PPE. 

 

Which is why subsidising the consumer's bills for a period would be alot better - yes people could and would try to fiddle things by bypassing meters etc, but thry do that anyway. 

[Michael_S]

34 minutes ago, Beelbeebub said:

Sadly, people will always try to diddle the system, whether it be a."free" air conditioner or a £120 million contract for faulty PPE. 

 

Which is why subsidising the consumer's bills for a period would be alot better - yes people could and would try to fiddle things by bypassing meters etc, but thry do that anyway. 

Logically I think you are right but in reality people seem to be very short-sighted and only look at the up front cost - se for example EVs.

[Michael_S]

9 hours ago, JohnMo said:

Just run a timer. Octopus offer a similar tariff to cosy for storage heaters. Nothing wrong with a smart meter, saving me a fortune now it's up and running.

 

My heart bleeds at the 75p per kWh generated whether exported or used. Madness they get that much.

 

 

People chose to invest in a potentially risky new technology based on and agreed set of returns.  Which other contacts should the govt renege on?  I am a civil servant, you probably think I am overpaid and the government should unilaterally cut my salary including for the work I have already done this month?

[Michael_S]

11 hours ago, sharpener said:

 

News of the scheme's death seem to have been greatly exaggerated - business as usual for the Grauniad. 

 

New press release says "residents will benefit from cool homes during a long, hot summer, without burning harmful fossil fuels"

 

Well while there is still gas in the mix they cannot prevent AC from using fossil fuels so I am not sure encouraging its use is a good idea. Blocks of flats will be ruined by higgledy-piggledy installation of different AC units like they are in Korea. And the resulting heat put into the atmosphere will make it worse for everyone else, leading to an arms race.

 

Nor should we be encouraging the use of resistive heating (Fischer should be banned from operating in the UK).

 

Other than that the extension of the scheme is a good thing.

 

 

There seems to be an odd puritanism with regards to AC.  It is apparently fine not to want to feel too cold but want to not feel to hot and you are a selfish climate wrecker.

[JohnMo]

35 minutes ago, Michael_S said:

People chose to invest in a potentially risky new technology based on and agreed set of returns.  Which other contacts should the govt renege on?  I am a civil servant, you probably think I am overpaid and the government should unilaterally cut my salary including for the work I have already done this month?

Not sure what was risky about PV, domestic systems had been about since the 70s, just super expensive. Once the feed in tariff disappeared, funny old thing prices dropped like a stone.

 

Not sure where your job fits in to the discussion!

 

35 minutes ago, Michael_S said:

It is apparently fine not to want to feel too cold but want to not feel to hot and you are a selfish climate wrecker

Doing cooling when powered by PV, is better than heating and having to take energy from the grid. Even better if your getting paid 75p per kWh while you are doing it, whatever the inflation index is used. But not that great for the tax payer.

[ProDave]

52 minutes ago, Michael_S said:

There seems to be an odd puritanism with regards to AC.  It is apparently fine not to want to feel too cold but want to not feel to hot and you are a selfish climate wrecker.

And if you have PV on your roof, you can pretty much guarantee when you need to run your cooling system, there will be enough power from the PV to power it, so no demand on the grid.