Rethinking the mindset for mass retrofit - a provocative idea

[sharpener]

4 minutes ago, ProDave said:

 

I have given up counting how many heating systems I have worked on that have never been working properly since installation, the usual faults are original plumbing or wiring simply done wrong so the system is not shutting off when reaching desired temperature.

 

If so many installers cannot get the controls for a standard boiler install correct, then what hope of getting an ASHP install correct?

 

Perhaps trying to get the manufacturers to standardise the electrical interface and make it more like a standard boiler controls input would help?

 

Yes, I agree with all the foregoing and if they can only paint by numbers then a standardised set of connections - ideally colour coded like a motorised valve - would seem to be the answer. Actually I think all it needs is two inputs (ideally at mains potential not voltage free), one to call for the DHW set point and one for the heating (which might or might not be the same temp). Most existing time controllers already provide these outputs.

 

And WC of course, inhibited by the call for HW. My Vokera boiler didn't do this and the plumbers had no idea how to go about it because (in 2009) they had never even heard of WC. Easily fixed with a small mains relay inside the wiring centre.

[ProDave]

11 minutes ago, RichardL said:

+1 This
Ideally the controls market would be separate from the A2W/A2A (Whatever) systems like they broadly are with gas/oil.
Granted currently an on/off dry contact for a boiler is a bit crude - but its simple and doesn't fail when the internet/cloud/wifi/firmware version buggy (choose any) is down

but
The added value this time round should have been standard ways to talk to the smart meter and work out current cost export import etc - I mean talk to the smart meter direct - not some fancy integration across the cloud which a techie can keep working but joe public has no interest or time (quiet rightly) in fiddling with.

No one wants to call a software engineer to fix their CH.

I think the Grant Aerona that I wired just over a year ago has the right balance.  Basically it has 2 call for heat inputs, one for DHW and one for heating, so each can be supplied at a different temperature.

 

My own LG is at the other end of the complicated spectrum, it really makes itself hard to control by anything other than it's own very complicated and not intuitive control panel * and then requires a LOT of connections from the ASHP into the house to control things like individual motorised valves.  And that is the problem, you need to read and understand the manual to work out how each particular system works.

 

* I wanted my heating controlled by a standard central heating type time clock that everyone understands, so anyone can change the heating or hot water times, I had to get a little inventive, particularly with the hot water to achieve that with the LG.

 

I guess companies like Octopus breaking into this market will only install 1 or perhaps 2 makes of heat pump and their installers will be familliar with them.

[JamesPa]

4 minutes ago, RichardL said:

Ideally the controls market would be separate from the A2W/A2A (Whatever) systems like they broadly are with gas/oil.
Granted currently an on/off dry contact for a boiler is a bit crude - but its simple and doesn't fail when the internet/cloud/wifi/firmware version buggy (choose any) is down

+1 on this one, but a problem which is outside our 'control'. 

 

Flow temp, heating/cooling and on/off are the essential controls for the heat pump part, and a standard interface to these would separate the control complexity from the basic heat engine.  Individual installers would then become familiar with one or two controllers, and could pick the heat engine suitable to the situation.  Homely is an attempt to do this, but, at least in some cases, requires a cloud connection which, as you say, is not on for a central heating system.

 

I fear, however, that the might of the big manufacturers will perpetuate the current situation, so, unless regulation steps in (which would, I imagine, need to be at the level of the EU as a minimum to sway manufacturers), I think it likely that the heat engine and the controls will remain inextricably linked for the foreseeable future.

[RichardL]

1 minute ago, ProDave said:

* I wanted my heating controlled by a standard central heating type time clock that everyone understands, so anyone can change the heating or hot water times, I had to get a little inventive, particularly with the hot water to achieve that with the LG.

100% with you on this one -  aligned as a target on my own system as I phase out Oil and Phase in A2A & IR panels etc.

Multiple local thermostats - yes
Single central clock and on/off switch across the various technologies - ideally yes

[JamesPa]

24 minutes ago, RichardL said:

100% with you on this one -  aligned as a target on my own system as I phase out Oil and Phase in A2A & IR panels etc.

Multiple local thermostats - yes
Single central clock and on/off switch across the various technologies - ideally yes

+1 but - On/off switch or temperature control?  I don't think most people want to freeze at night (some are forced to sadly), but they do want to turn down the central heating quite a lot, which should be achieved by turning down the flow temp (although they shouldn't have to know this!).  This may or may not result in the actual heating turning off, again they shouldn't have to know this.

[RichardL]

1 minute ago, JamesPa said:

but - On/off switch or temperature control?

Agreed - not for temp control - more a few zones in the house for global heating on/off or broad zone (upstairs/living etc) on/off.
Temp control is (probably) a more local or zone thermostat.

On off for seasonal, or overnight - in my case I don't heat overnight - but absolutely that depends on your heating technology/building tradeoffs.
 

[PhilT]

https://www.theheatinghub.co.uk/articles/hybrid-heat-pumps

This might have been a good way to encourage large scale transition but, incredibly, they now don't qualify for any grant! Sadly I think it will be a slow burn based on a combination of homes' forced need for replacement of ageing equipment, an increasing gas cost relative to electricity, and improving HP technology/COP in conjunction with reduced up front cost through economies of scale

[Nick Thomas]

Interesting thread, thanks for starting it.

 

11 hours ago, JamesPa said:

A2A is definitely part of the 'mix'

 

The house up in Shetland has A2A. It really needs airtightness work to keep the warmed air inside the house, so isn't exactly a "plug and play" measure. The noise may put some people off too - it's definitely "there", but I managed to get used to it. Nice to have the air-conditioning functionality in summer, too!

 

The UK trails much of the rest of Europe by quite some way in terms of heat pump installations. Much of the problem is political, rather than technical, so I'm skeptical that trying to avoid the political considerations will lead to a formula that will increase the installation rate significantly.

 

Right now, the fight is very much to preserve that measure to ban new-build gas boiler installs by 2025, never mind retrofit.

[JamesPa]

3 minutes ago, Nick Thomas said:

The UK trails much of the rest of Europe by quite some way in terms of heat pump installations. Much of the problem is political, rather than technical, so I'm skeptical that trying to avoid the political considerations will lead to a formula that will increase the installation rate significantly.

For the avoidance of doubt Im not denying the political issues and agree that they are major, I'm just trying to avoid discussing for now while we work out what we want the politicians to enable.  They don't have the solutions, of that I'm convinced, the public wont stand vast subsidies for any length of time, and neither will the public stand being forced to spend 15K on replacing a gas boiler with new technology when replacing it with a gas boiler would cost say 4K (installed).  Its just not saleable! 

 

The 'hydrogen ready' brigade know this and are ruthlessly exploiting it, even though they also know that hydrogen will almost certainly cost 30% more than electricity, and have only the same efficiency as gas, thus will be 4 times more expensive to run that a heat pump.  They dont actually care about this, it simply means that they can keep selling gas boilers and, when the truth is outed, claim that the switch away from gas is 'too expensive to afford'.

 

So we need workable ideas for heat pumps which could be implemented by politicians/the industry.  Once we know what these workable ideas are (hence the post and the invitation to critique it), perhaps we could go about lobbying.  

 

So far I think the summary is:

 

1. nobody has yet  put forward a solid reason to dispute the basic premise of the post (where is @markocosic - he usually disputes any suggestion that departs from absolute perfection)

2. many agree that it would be helpful, perhaps necessary, to separate control from heat engine

3. all agree that there are regulatory/political barriers

4. several thing that A2A also forms a part of the toolbox

5. most/all agree that the heating technology is only a part of the 'system solution' and that insulation is the other major physical part.  Incidentally I agree with this but would argue that the 'system solution' includes the regulatory and industry environments and that these are equally a part, but that until we understand the technical solutions we cant get these right.

 

 

[gregh]

1 hour ago, Dave Jones said:

pre- cavity wall properties that are suitable for external insulation are the low hanging fruit. Council housing etc.

Except most planning authorities block this for aesthetic reasons

[Dave Jones]

10 minutes ago, gregh said:

Except most planning authorities block this for aesthetic reasons

 

crazy isnt it, they also block solar for same reasons.

[markocosic]

12 minutes ago, JamesPa said:

where is @markocosic - he usually disputes any suggestion that departs from absolute perfection)

 

Careful there. That's sailing close to stating that the chap is always being a knob; not to mention nothing like the truth.

 

 

In the UK I have non MCS, secondhand when installed, solar PV. A non MCS air to air heat pump that electrifies 80% of space heat for £1500 whilst also delivering cooling. 

 

Most of the results for minimal cost/effort.

 

 

What I do think is dumb is expending lots of effort on a bespoke design that achieves a meh result.

 

 

The difficulty you'll find with the "just whack a high temperature heat pump on" crowd mentality is (1) turndown at part load and (2) ensuring they're aggressively weather compensated outside of peak demand such that the sCOP isn't destroyed.

 

All well and good in theory. Now go find some that actually deliver anything like what you think they do. 

 

 

Octopus hired the RED chap to cook up a high temperature propane unit that'll have good turndown that isn't £10k a pop. They're not there only ones working on the same.

 

Previous advice was sit on the fence a while longer waiting for the kit to be available. Buy induction home and pans in the meantime; add pv if not already there which has a better payback on cost and carbon; chuck in an air to air unit that'll do your summer cooling AND reduces the amount needed from the radiators etc. All stuff you want anyway and is usefully absurdly in the form you'd like today.

[markocosic]

1 hour ago, JamesPa said:

Ideally the controls market would be separate from the A2W/A2A (Whatever) systems like they broadly are with gas/oil.

 

Ideally not.

 

Ideally the controls would work AND the end users would do trying to dictate how physics works / knowing better than the device how to achieve the desired setpoints.

 

Ideally they wouldn't rely on internet connectivity or have any connections to servers in hostile states though.

[ProDave]

The problem with "doing things right" i.e properly balancing UFH loop flow rates so individual room thermostats are not needed, and properly set up weather compensation, is they take time to get right.  That's fine for self builders who are prepared to learn now to set up their particular system and take the time to get it to work correctly in practice.  But if you are expecting an installer to do all that, get it right first time, or keep coming back to adjust things until it is right, that is just going to add £00's to the cost, and at the same time disappoint the customer "he had to return 5 times to adjust things before he got it working properly" sort of comments.

 

So for the mass market boiler replacement customers individual room thermostats, and no or basic weather compensation is the best you will do.

[markocosic]

31 minutes ago, gregh said:

1 hour ago, Dave Jones said:

insulation are the low hanging fruit. Council housing etc.

Except most planning authorities block this for aesthetic reasons

 

Sue them for damages. Cost of additional energy and CO2 offsets for the next 50 years. Haul them in front of their MP and the papers. Indefensible behaviour not in the overall public interest.

 

Or just render your property including 200 mm of EPS in the render and invite them to go do one.

 

Planning is not required for EWI any more so than it is for render. It is not legally an extension. Permitted development in the cast majority of cases.

 

(my brother told Cambridge city council to go do one when they demanded a planning application for EWI; and you'll find that in their own solid walled properties that for EWIed there's no record of a planning application)

 

The mistake that many make is asking permission of somebody who just loves any excuse to make you jump through hoops.

[MikeSharp01]

6 minutes ago, ProDave said:

But if you are expecting an installer to do all that, get it right first time, or keep coming back to adjust things until it is right, that is just going to add £00's to the cost, and at the same time disappoint the customer "he had to return 5 times to adjust things before he got it working properly" sort of comments.

This should be solvable with software that gathers the data and adjusts settings - not sure why this not already an option.

[markocosic]

5 minutes ago, ProDave said:

So for the mass market boiler replacement customers individual room thermostats, and no or basic weather compensation is the best you will do.

 

You're looking at sCOP 2.8ish at 55C or sCOP 2.3ish at 65C all year.

 

This falls below the sCOP at which the government considers there to be any carbon savings and more importantly perhaps below the sCOP at which you don't cause higher operating costs.

 

Probably better to sell them A2A units at heating sCOP 5ish then let money saving expert show them how to use these to offset gas use.

[Iceverge]

I don't think A2W ASHP is the solution. 

 

Not until there's a bolt on replacement for £1000 that'll provide 70⁰ water at a COP of 3. That seems unlightly. 

 

Many users here have great success with ASHP but most of that can be attributed to tackling the fabric first, not the ASHP. 

 

 

[markocosic]

1 minute ago, MikeSharp01 said:

This should be solvable with software that gathers the data and adjusts settings - not sure why this not already an option

 

The dumb mechanical valves setting flow through radiators and the dumb UFH controls in use cannot be adjusted with software.

 

Upgrading these (to dumb mechanical valves set right) is the much of the cost.of the installation.

 

eTRVs don't set flowrates before you ask. They're on off devices. The valve bodies are what balance the system. 

[markocosic]

1 minute ago, Iceverge said:

provide 70⁰ water at a COP of 3

 

Why those figures?

 

It really isn't needed in the vast majority of houses.

 

The gas boys and girls would like the market to think that this is the mass market but actually no, the *mass* market really is about 55C

[Iceverge]

7 minutes ago, markocosic said:

 

Why those figures?

 

It really isn't needed in the vast majority of houses.

 

The gas boys and girls would like the market to think that this is the mass market but actually no, the *mass* market really is about 55C

 

Top of my head.

 

Something that will deliver enough energy through small bore pipes to small rads before all the heat blows straight out through the uninsulated suspended floors and rattily single glazed sash windows again. 

 

I tried in my parents house to run the rads at 50deg. It worked, BUT only if the wood fired Rayburn was kept fired for at least 16hrs per day.  I wouldn't like to see the utility bill for the equivalent energy if bought in. 

[ProDave]

20 minutes ago, markocosic said:

You're looking at sCOP 2.8ish at 55C or sCOP 2.3ish at 65C all year.

Which is why fitting an ASHP but keeping the original radiators is going to under perform.  Yes reducing the temperature in radiators when possible by WC will improve that, but is a sticking plaster compared to doing the job properly and heating by UFH with sub 40C water all year.  That is the issue, we are trying to do half a job here, not properly upgrade the old properties.

[offthepiste]

Re @ProDave comment regarding octopus offering ASHP.

 

Whilst I absolutely support ASHP suspect the octopus initiative will automatically attract serious negative (gutter) press.

 

I answered their online questionnaire knowing that it should not recommend ASHP without first having addressed insulation and airtightness issues we previously had in our victorian terraced house. 

 

The implication from the outcome of the questionnaire was that I was good to go in installing an ASHP without addressing the other - very expensive issues.

 

octopus should seriously be upfront about these issues.  

[markocosic]

20 minutes ago, Iceverge said:

...tried in my parents house to run the rads at 50deg. It worked, BUT only if the wood fired Rayburn was kept fired for at least 16hrs per day. 

 

So...you proved that it'll work just fine with a heat pump running and 50 degC...even if you were to switch the thing off for 8 hours a day?

 

Why do conclude that 70 degC is required? (even on this sample of one)

 

16 minutes ago, ProDave said:

...a sticking plaster compared to doing the job properly and heating by UFH with sub 40C water all year. 

 

UFH isn't required for adequate (sCOP 3.5+) enough results to make the installation worthwhile. (from a carbon and marginal operating cost perspective)

 

Agree that turning most houses into rubble upon which to erect a new timber framed or lightweight block constructed house would be ideal. In the interim...

[ProDave]

3 minutes ago, markocosic said:

Agree that turning most houses into rubble upon which to erect a new timber framed or lightweight block constructed house would be ideal

The 21st Century slum clearance project.  Who is going to fund it?

 

Particularly in many cities there are a lot of old rubbish houses with big gardens, and rebuilding whole areas with slightly smaller gardens would fit more in.

 

All I can say is I would not want to be owning one such old leaky uninsulated house right now and I certainly would not buy one unless it was very cheap.