Rethinking the mindset for mass retrofit - a provocative idea

[Roger440]

2 hours ago, JamesPa said:

Well at least some element of optimism has returned at last, thanks!  Seriously!   And thanks for the comment on MCS too, it feels, from interactions on this forum and elsewhere, that MCS is the root of many evils.

 

So, back to the solution.   I can readily believe that the design/assessment process can be automated/simplified.  However the actual plumbing cant be (I dont think).  Currently we replace much good stuff with alternative good stuff, causing much cost and disruption, how much of that is necessary, what would it take to make it unnecessary, what tests do we need to do to find out if the current installation is adequate?

 

So can we get away in many or most cases with not replacing

 

a)the DHW tank

b)the cold feed to the DHW tank

c)the primary feeds to the Central heating

d)feeds to the radiators

e)miscellaneous things like mag filters etc

f)things that are anyway counterproductive like room thermostats (other than any in the HP controller itself), timers etc

 

 

Some of the quotes I have received form our illustrious industry included replacing all of these except d, and one involved fitting a Nest thermostat (really?)

 

My feeling is that the answer, in many cases, is that we could get away with not replacing much of this, sometimes with a small performance penalty, sometimes with none..

 

My fear is that the industry replaces them all in order that they can justify fitting the manufacturer supplied pre-plumbed cylinder which means that they have to know diddly-squat about the system that they are installing and can employ rookie plumbers to do the install.

 

Am I wrong and whats the answer?  Is it to separate out system design and installation (as we do with building - architects and builders are separately employed by the customer).  Currently MCS expressly forbids this!

 

Again ideas, preferably positive, on a postcard please.

 

As i said in my first post, your suggestions make good sense.

 

However, i see no cause for optimisim regarding actual real world action. Sadly, i fear it will simply remain a discussion point here. Aside from it being an interesting discussion, are you proposing to actually do something about it?

 

[JamesPa]

3 hours ago, ProDave said:

So if the bottleneck is installers (assuming supply could then keep up if the installers could be found) then the solution has to be simplify heat pump controls.

 

They already mimic a system boiler from a plumbing perspective, in that they just have water flow and return.  It is the electrical controls that complicate things.

 

I have already mentioned the Grant ASHP's seem nearest to that at the moment with just a call for heat for HW and a separate one for heating.  Surely that is not too much of a step change for the average electrician wiring a heating system to get used to two separate call for heat commands?

 

Plumbing wise, dump any 3 port mid position valve and replace with two 2 port valves or a 3 port 2 position valve.

 

So there you have a relatively simple swap a system boiler for an ASHP with little change. BUT the water temperature maxing at 55 degrees may not be enough and it won't be optimum efficiency. 

 

So now you offer customers a choice.  Simple swap with little plumbing alterations for a cheap price, BUT warn them of the lower temperature and that it may under perform.  Then offer the upgrades, new larger heat pump cylinder, larger radiators IF they find they need them.

 

Of course for the huge percentage oh homes with a combi boiler and no HW tank you have to fit a HW cylinder with a heat pump, so many will see that as too expensive and unnecessary.

 

Like the discussion in the GW thread about cars, what is likely to happen is people won't be swapping heat pumps in anything like the required volumes and if new boilers become impossible to get the immediate task will be maintaining ever ageing boilers.  Lets hope the spares supply side steps up, once the easy option of replace rather than fix has gone.

Thanks, its pretty much where I started this thread but then I was largely (not entirely) shot down!

 

 

1 hour ago, Roger440 said:

However, i see no cause for optimisim regarding actual real world action. Sadly, i fear it will simply remain a discussion point here. Aside from it being an interesting discussion, are you proposing to actually do something about it?

 

Im not in a position to do anything about it directly, as I have no connection with the industry.  But I can lobby MP and others, and so can other people, and if there were some sort of consensus about a) the objective and b) possible ways forward it might make a difference.  In addition there are various people on this forum and others who do have a connection with the industry and if, by discussion, we can shift the thinking a bit then maybe, just maybe, things can get better.  

 

 

 

 

Edited April 27, 2023 by JamesPa

[markocosic]

4 hours ago, JamesPa said:

Currently we replace much good stuff with alternative good stuff, causing much cost and disruption, how much of that is necessary, what would it take to make it unnecessary, what tests do we need to do to find out if the current installation is adequate?

 

Do you live in the same capitalist world as the rest of us?

 

Yes?

 

 

Then this is stupidly simple.

 

 

Say there are 20 jobs available.

 

Say 10 are "give me a complete new system" and take moments to price up; and involve plenty of work for which you charge.

 

Say 10 are "tell me everything there is to know about heat pumps and work out how to reuse all my existing stuff" and take far longer to price up; and involves more unpaid work upfront; potentially more unpaid work later; and less work for which you can actually charge.

 

I say this because those latter 10 are customers who are paid PAYE; haven't had to work out the true cost of doing work in recent living memory; and cannot comprehend that all the time you spend selling / marketing / designing / quoting / revisiting has a cost associated with it.

 

 

Say there are 10 installers. They are not paid PAYE regardless of whether what they're doing is value-adding or not. They do not exist to serve you at their own expense.

 

They're going to go for the first 10 jobs. Cost is no object. It's whatever you can get away with charging subject to perceived value by the customer. The latter 10 simply don't happen

 

 

 

Say there are 20 installers. There'll be some competition. The first 10 will pay a market limited rate for the complete installs. The latter 10 will pay a reduced cost for less work PLUS the cost of all the other nonsense that they think is free. It'll probably not be far off the cost of the first 10 if you're good at knocking out the exact same thing time and time again; and certainly not on a lifecycle basis if there's any compromise in the performance that results.

 

Solutions for reducing sales/marketing costs (acquiring and qualifying leads - i.e. weeding out the time waster customers) and automating surveying/design and procuring standardised packages in volume will reduce costs for all; but disproportionately so for those knocking out full packages.

 

 

Say there are 30 installers. The market rates drop to the point that the more capable ones quit the industry in favour of something that pays better. You're left with the only just competent enough to keep the lights on crowd. Case study: your average domestic gas fitter; now that those who trained in the 70s and 80s have died?

 

 

In answer to your query what you need...is enough supply for it to be remotely worth effort of somebdoy even considering taking on the crappier jobs.

 

Everything else is more of a symptom than a root cause.

 

 

MCS, which puts up barriers to entry whilst doing literally zero to ensure compliance with any kind of standard, results in what is in effect a government sanctioned / government subsidised union.

 

Opposite of what you're after here.

 

 

Dumb controls are a dumb idea.

 

Products whose consumer facing controls suck less are a great idea.

 

See also products designed to reduce installation costs. Include the fill loop. Include the filter. Include the pump. The expansion vessel. The controls etc. Manufacture of a turnkey box rather than a pallet of bits.

 

That'll come as local volumes become...less artisan.

[JamesPa]

 

3 minutes ago, markocosic said:

In answer to your query what you need...is enough supply for it to be remotely worth effort of somebdoy even considering taking on the crappier jobs.

 

Everything else is more of a symptom than a root cause.

 

 

MCS, which puts up barriers to entry whilst doing literally zero to ensure compliance with any kind of standard, results in what is in effect a government sanctioned / government subsidised union.

 

Opposite of what you're after here.

 

OK so we are beginning to agree, rather a lot actually 😊!

 

The question then is, how to expand the supply?  Personally I can see only one credible source of a large enough pool of labour which is also interested in smaller jobs - because its their bread and butter work - namely local plumbers and local electricians, who are currently completely excluded from the market. 

 

Thus two questions arise

 

1)What do we have to do to either ensure they have the skills, or subdivide the job so they can do it with the skills they have?

2)What changes to regulation are needed to alter the market so they are included not excluded?

 

it seems to me that 1) comes down to three options

 

a) train

b) separate the job (so the difficult stuff (design and config) is done by a different set of people)

c) dumb down

 

Not sure which is best, most likely a combo

 

It seems to me that 2) comes down to

 

a) scrap MCS as a condition for government grants do we need to replace it with anything or can we rely on one of the existing bodies 9hetas, NICEIC etc), or just the market itself (local plumbers and local electricians value their reputation)

b) scrap MCS as a condition for permitted development

 

Does that just about cover it?

 

Of course it may be that there still aren't enough plumbers and electricians in the country to cover the workload (unlikely, because they fit 1.6M gas boilers a year).  That's a whole other problem which, if I were to speculate here on the reason, risks opening up another can of worms.  However even if this is the case, opening up the market to local plumbers and electricians surely is a good start, in my humble opinion the only real option to get the volume needed.

 

 

 

 

[JohnMo]

There are only three complications to a heat pump, that a normal plumber needs to get his around. Everything else should be normal stuff.

 

1. Sizing the heat pump, for a retrofit taking the energy consumption for December and or January, will give you a good place to start, just a matter of a simple calculation and possibly a loading factor to make the average more realistic and representative of peak loading.

 

2. Radiators, as said give two options cheap and simple install, little or no changes, or more suitable install of correctly sized rads.

 

3. Hot water, keep existing cylinder, if one exists, heat via existing coil, top up with immersion. Or new cylinder. Or hot water on demand electric heater.

 

A set of guidelines in plain English for the customer to tune weather compensation, which should really mandatory, to enable during commissioning, so the heat pump always operates at the lowest temp possible.

[RichardL]

2 hours ago, JohnMo said:

. Sizing the heat pump, for a retrofit taking the energy consumption for December and or January,

That rule of thumb, if reasonable, is so much easier than the current MO of analyse heat loss in all rooms etc.

I'm sure the latter is accurate, but if the former is close enough and based on real world heating requirements - thats the sort of thing any customer can also do to ball park the install size.

IMHO That sort of - I can double check the 'expert/trader' & in my own mind confirm its the correct product process massively helps take-up.

[JohnMo]

I just calculated the following and it gives a close estimate to the heating demand I have.

 

3700 (total gas usage for Jan and Feb including DHW) / 1488 (number of days x 24) x 150%

 

Gives around 3.7kW. Which fairly close to my heat demand at -9 (which we had over a couple of weeks during the period). 

 

The realistic ASHP would be 5 to 6kW. I have chosen a 6kW one as it happens.

 

 

[Roger440]

1 hour ago, JohnMo said:

I just calculated the following and it gives a close estimate to the heating demand I have.

 

3700 (total gas usage for Jan and Feb including DHW) / 1488 (number of days x 24) x 150%

 

Gives around 3.7kW. Which fairly close to my heat demand at -9 (which we had over a couple of weeks during the period). 

 

The realistic ASHP would be 5 to 6kW. I have chosen a 6kW one as it happens.

 

 

 

Im on oil. So no meter. So no easy way to tell. I can tell you annualmconsumption, but thats not really useful

 

But, not that many oil installs, so i guess only a minor issue.

 

 

[Radian]

3 hours ago, JohnMo said:

1. Sizing the heat pump, for a retrofit taking the energy consumption for December and or January, will give you a good place to start, just a matter of a simple calculation and possibly a loading factor to make the average more realistic and representative of peak loading.

In the quest for automation: For installations with a DCC feed from a smart meter, all you need is the owner's permission to read the GUID/MAC/EUI off the back of the IHD, along with their postcode and you've got a treasure trove of data to work with potentially covering several years. A single bit of code could take this info as input and spit out a sizing while you wait.

[JohnMo]

But you really only need to do do a room calculation of heat loss for sizing emitters, a whole house will be fine for sizing the overall heat demand, such as the calculation spreadsheet on building (and work out floor, wall and roof U values) 

 

@Radian posted just before me

Edited April 27, 2023 by JohnMo
Beaten to the post

[JamesPa]

2 hours ago, RichardL said:

That rule of thumb, if reasonable, is so much easier than the current MO of analyse heat loss in all rooms etc.

I'm sure the latter is accurate, but if the former is close enough and based on real world heating requirements - thats the sort of thing any customer can also do to ball park the install size.

Actually there is ample evidence to suggest that a room by room analysis is not at all accurate.  See this report

 

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/606834/Report_on_compliance_with_MCS_installation_standards_v32.pdf

 

and in particular this graph

 

 

 

My distinct feeling is that whole house sizing based on experimental measurement may be a much more accurate than trying to do the fabric calculations.  Of course I believe the physics of the calculations, but there are quite a few real uncertainties and, if my personal experience is anything to go by, surveyors ignore too many important factors.

 

 

 

Edited April 27, 2023 by JamesPa

[Radian]

3 minutes ago, JamesPa said:

My distinct feeling is that whole house sizing based on experimental measurement may be a much more accurate than trying to do the fabric calculations.  Of course I believe the physics of the calculations, but there are quite a few real uncertainties and, if my personal experience is anything to go by, surveyors ignore too many important factors.

 

"As built" is rarely as good as "as designed". Sloppy detail, airtightness etc. make a spreadsheet analysis liable to inaccuracies.

[JamesPa]

8 minutes ago, Radian said:

 

"As built" is rarely as good as "as designed". Sloppy detail, airtightness etc. make a spreadsheet analysis liable to inaccuracies.

The above data shows that the installers usually overestimate the demand, by a significant, one might say shocking, margin. 

 

I must say that is also my personal experience.  16kW estimated by MCS surveyors (2 off), 10.5kW by me using MCS assumptions, 7.5kW actually measured.

 

In a sense it doesn't matter whether they over estimate or under-estimate, the differences shown in the plot are too significant to ignore and have a major impact on system design.  I feel it makes a good, possibly excellent, case for discontinuing the practice of doing the whole house sizing by adding up the room by room calculations.

 

I accidentally pasted the wrong plot (the one I posted includes GSHPs), but the correct one (below) is not much different

 

Edited April 27, 2023 by JamesPa

[S2D2]

Sizing is a very simple process if a smart meter is installed, there are companies that provide this service for far less than the £300-£400 I've seen quoted for ASHP surveys:

 

https://www.buildtestsolutions.com/building-performance/smart-htc-heat-loss-calculation

 

The company behind Bright are experimenting with this I believe, and there's no reason it couldn't be done with £25 worth of (reusable) sensors rather than their fairly ridiculous £230 fee. Scale to government level and this gets you a sizing for every property that is likely to need a boiler replacement in the next year for peanuts.

 

It's a simple regression fit of data and highly accurate when I did it DIY on my property, came within a couple of kWh on the design OAT.

 

Came out as a 4kW ashp for me, whereas MCS calc came out at 6kW.

 

Just the other £14.5k to worry about then.

[ProDave]

24 minutes ago, S2D2 said:

Sizing is a very simple process if a smart meter is installed, there are companies that provide this service for far less than the £300-£400 I've seen quoted for ASHP surveys:

 

https://www.buildtestsolutions.com/building-performance/smart-htc-heat-loss-calculation

 

The company behind Bright are experimenting with this I believe, and there's no reason it couldn't be done with £25 worth of (reusable) sensors rather than their fairly ridiculous £230 fee. Scale to government level and this gets you a sizing for every property that is likely to need a boiler replacement in the next year for peanuts.

And how would it separate heating energy use from "other" energy use?  In a low energy house like ours, heating is NOT the biggest user of energy in this house.

[JamesPa]

17 minutes ago, S2D2 said:

Sizing is a very simple process if a smart meter is installed, there are companies that provide this service for far less than the £300-£400 I've seen quoted for ASHP surveys:

 

Thanks, I thought so, and way more accurate than any 'MCS' calculations I have no doubt.

 

17 minutes ago, S2D2 said:

Just the other £14.5k to worry about then.

 

This is made up of

 

overengineering

unnecessary replacement of perfectly good kit

profiteering

 

The first is at least in part fixed by whole house sizing based on experimentation (and with it some other problems go away - eg buffer tanks in many cases).  Methods to fix over sizing of rads still to be addressed.

 

The second was the original thrust of this thread, we still need more discussion on this although @JohnMo has made very sensible suggestions and if we stop overengineering the size quite a lot of the unnecessarily replaced kit drops away (because it will be obvious that its unnecessary to replace it)

 

The last will, IMHO, potentially be fixed by opening up the market to local plumbers and electricians, whose bread and butter jobs are 1-5K in size not 20K plus, and who, so far as I can see, are the only credible source of labour for volume delivery.  I'm still waiting for @markocosic to comment on my response above and that of @JohnMo which were both triggered by his entirely valid comments on supply capacity and the somewhat disastrous effect the lack of capacity has on the market

[JamesPa]

5 minutes ago, ProDave said:

And how would it separate heating energy use from "other" energy use?  In a low energy house like ours, heating is NOT the biggest user of energy in this house.

Simple in the bulk of retrofit cases. 

 

In most retrofit circumstances gas=heating, electric=everything else.  Ok, there might be a bit of gas used for cooking, but insignificant in comparison with the heating load and, by comparison with the errors with a theoretical calculation (see scattergram above, entirely negligible.

 

 

Edited April 27, 2023 by JamesPa

[S2D2]

3 minutes ago, ProDave said:

And how would it separate heating energy use from "other" energy use?  In a low energy house like ours, heating is NOT the biggest user of energy in this house.

Yes apologies this is only for replacing gas heating. DHW and cooking can be estimated from summer use, or assume an average to reduce the monitoring period to just December.

[S2D2]

6 minutes ago, JamesPa said:

Methods to fix over sizing of rads still to be addressed

Again seems simple, assume the current rads are appropriately sized and adjust for the new flow temp using the manufacturers heat output function. Usually about 3x. Blame the homeowner if it ends up undersized.

 

Open that replacement job up to any local plumber and I reckon you'd see £2.5k drop off the quote as a total guess.

[JamesPa]

1 minute ago, S2D2 said:

Again seems simple, assume the current rads are appropriately sized and adjust for the new flow temp using the manufacturers heat output function. Usually about 3x. Blame the homeowner if it ends up undersized.

 

Open that replacement job up to any local plumber and I reckon you'd see £2.5k drop off the quote as a total guess.

I think it probably is nearly that simple, but I might suggest that your algorithm will result in lots of unnecessary replacement so needs some refinement

 

Many retrofit situations will have rads dating from before loft, wall and window insulation were upgraded, and the rads were probably oversized initially.  I wouldn't be at all surprised if, closer to the truth, is that existing rads will be sufficient in many, perhaps most cases at say 55C flow temp.  Bear in mind we are talking delta t of 5 vs 20, so the average temp of the rad does not differ as much as the difference in flow temps.  Somehow a bit of refinement on your basic algorithm is needed (perhaps another experiment, turn up all trvs to max for a day, shut the doors, measure the temperatures?)

 

But you are doubtless right that replacement by a local plumber will be cheaper than replacement by a MCS contractor.

 

[Roger440]

Maybe historic oversizing actually works in favour of simplification????

[markocosic]

3 hours ago, Radian said:

In the quest for automation: For installations with a DCC feed from a smart meter, all you need is the owner's permission to read the GUID/MAC/EUI off the back of the IHD, along with their postcode and you've got a treasure trove of data to work with potentially covering several years. A single bit of code could take this info as input and spit out a sizing while you wait.

 

Already happening.

 

The firms that use that as an initial assessment/final sanity check also do more detailed designs though.

[S2D2]

36 minutes ago, JamesPa said:

I think it probably is nearly that simple, but I might suggest that your algorithm will result in lots of unnecessary replacement so needs some refinement

 

Many retrofit situations will have rads dating from before loft, wall and window insulation were upgraded, and the rads were probably oversized initially.  I wouldn't be at all surprised if, closer to the truth, is that existing rads will be sufficient in many, perhaps most cases at say 55C flow temp.  Bear in mind we are talking delta t of 5 vs 20, so the average temp of the rad does not differ as much as the difference in flow temps.  Somehow a bit of refinement on your basic algorithm is needed (perhaps another experiment, turn up all trvs to max for a day, shut the doors, measure the temperatures?)

 

But you are doubtless right that replacement by a local plumber will be cheaper than replacement by a MCS contractor.

 

Okay, keep the current ratios between rad output and scale at a house level to the heat demand that pops out the automated calc.

 

This would adjust for improvements, and may come out as no change required.

[SteamyTea]

3 hours ago, JamesPa said:

I accidentally pasted the wrong plot (the one I posted includes GSHPs), but the correct one (below) is not much different

 

That looks a pretty good statistical fit to me considering the 'rules' say that a heating system has to cope with almost all the worse scenarios.

As it is all at the lower end of the scale, a double of very little i.e. estimated at 10 to 30 MWh and the actual is 10 to 10 MWh seems pretty reasonable, especially considering that it includes DHW and I suspect most of the houses are larger, two occupancy places i.e. retired people.

[markocosic]

8 hours ago, JamesPa said:

1)What do we have to do to either ensure they have the skills, or subdivide the job so they can do it with the skills they have?

2)What changes to regulation are needed to alter the market so they are included not excluded?

 

1) Attract higher calibre, numerate / literate folks into the industry by paying good money and eliminating the bovine excrement. (having to compete with fly-by-nights; having to waste time chasing/qualifying leads and completing non value add tasks) You don't actually want this job to be a low paid job just right now. It should be very possible/common to make six figures aged 25 to get the people you need fully bought in. Drop the rates later once they're hooked. In this respect it's a good idea to let te folks willing to pay £10k pay £10k right now.

 

2) Kill the MCS stranglehold. That eliminates the fly-by-night grant chasers AND a good chunk of non value add tasks. You keep the requirements (e.g. the technical requirements with regards noise for permitted development) but make it the job of planners to enforce planning conditions (e.g. please prove it's adequately quiet, where here are the requirements lifted from the old MCS standards, and if you meet them them it's deemed fine, but you don't need to partake in the rest of the MCS charade)

 

Relax a few planning conditions too. They're asking for units to be too small. It should be permissible to have both a heat pump and an air conditioner. There shouldn't be stupid restrictions on siting R290 propane units near to doorways whilst it's still ok to keep two 15 kg propane cylinders inside your house.

 

Also

 

3) Look at communal ground arrays / hybrid arrays (substation gets a low temp air source heat pump on top that tops up a ground loop which nearby houses rent access to for £X per year and chuck a shoebox water:water heat pump in the kitchen to drawn from and feed the existing heating system; laying your LV cable reinforcement and FTTP at the same time as you lay the ground loop)

 

4) Quit subsidising new natural gas connections and subsidising marginal gas supply costs by moving the carbon taxes from electricity onto gas and moving the welfare taxes from electricity to central government and by requiring price transparency on the bills. (distribution and metering cost more than the electricity; historically)

 

5) Make use of / abuse advertising standards privileges / editorial accuracy requirements to kill the hydrogen nonsense; to kill the hit job articles; etc.

 

6) Take a chill pill. AC in cars is ubiquitous. Let people do AC in houses more easily. Don't mandate that in order to receive grant funding the heat pump must deliver heat AND hot water. Chop the available grant to £1k and apply the condition that it's a packaged/tested solution with a  sCOP of 5 or above. It's pish easy to install A2A units in this ball park. They work. People will rave about them.

 

Advertise the damn things on the side of city buses. I look at trolleybuses here in Vilnius (you know; those nuclear/solar/wind/hydro powered items of transportation that spank anything other than shoes and a bicycle on energy efficiency; have sweet fudge all reliance on Chinese batteries; and have been around in volume from Newcastle to San Francisco since the mid 20th century) advertising heat pumps and triple glazing to the general public and bang my head on the wall at the defeatist, stuck in the past, somebody else's duty to help me attitude that the UK has developed.

 

 

Pictures of buses because they illustrate how chuffing dumb/immoral the folks who have the power to be benevolent dictators but choose to lick the backsides of Musk, Xi, Putin et al rather than getting on with doing anything are in the UK.

 

See also PV diverters and house batteries. Dumbest not-even-zero-sum investment ever for UK plc.