BUS Grant requirements (conflicting info)

[Rudski]

HI Everyone

 

First post on here, I have been getting quotes for ASHP for our new build, will be SIPS panel, Triple glazed and MVHR, I have conflicting conversations with some of the providers as to whether I need  heating sources upstairs to qualify for the grant.

 

As we are trying to be airtight as possible we thought that UFH downstairs and heated towel rails in the bathroom and en-suite upstairs with MVHR would keep us warm, we hadn't planned for anything else upstairs, two companies have priced and not mentioned anything about radiators or UFH upstairs and a couple of others have said we do need heating up stairs to qualify for the BUS grant.

 

I cant find anything on the GOV website or any other websites that gives an answer to this, I don't want to sign a contract and then find that they cant claim the grant and we end up paying extra, and on the flip side I'm not sure I want to install something we never use because it's too warm, does anybody have any information that give a definitive answer to this?

 

Many thanks in advance.

Cheers

Mark 

[Post and beam]

I am going through exactly the same issue on my build that is underway. 

The company i paid a deposit to are making me nervous with what appears to be a lack of understanding of UFH/ASHP  installations. If i were not already a £6k deposit into them i would be looking for an alternative.

Their first proposal had larger than normal radiators upstairs. just as though we were re furbing an old house.

The house is Sips construction to a high standard and i dont believe i will need any radiators upstairs other than the usual towel radiators just as you describe. 

I had thought that i would install some small token radiators just to keep everyone happy and to ensure i get the grant. Now i think i may be forced to put the larger radiators in. And potentially ditch them once the dust settles.

The install companies rational is that the proposed 45 degree UFH flow temperature will require larger radiators to meet the needs upstairs.

This thinking illustrates 3 things....

# They ignored my requirement of a maximum design flow temp of 35 degrees.

# They do not appear to understand that the heat pump can deliver 2 independent temperatures to the 2 halves of the system.

# They do not appear to understand that the R290 in the heat pump can easily achieve a 'Normal' heating level to radiators if needed.

 

You will appreciate why this company is making me nervous.

 

keith

 

[JohnMo]

To get bus grant the install has to comply with MCS rules. MCS rules should be reviewed. But they require all habitable rooms to be heated.

40 minutes ago, Rudski said:

MVHR would keep us warm

MVHR is just ventilation - does not contribute to heating, does not move heat about to any degree.

 

24 minutes ago, Post and beam said:

They do not appear to understand that the heat pump can deliver 2 independent temperatures to the 2 halves of the system.

They can't as such, the same high temp is generated by the heat pump, if you want a lower temp it's mixed down as well as a high temperature it's done by mixing.

 

26 minutes ago, Post and beam said:

They do not appear to understand that the R290 in the heat pump can easily achieve a 'Normal' heating level to radiators if needed.

They can at the expense of CoP and actual running costs.

 

27 minutes ago, Post and beam said:

had thought that i would install some small token radiators just to keep everyone happy and to ensure i get the grant.

They have to do a full system design, token efforts aren't really allowed. The grant money isn't just for you, it's for future owners of the house also, they need to design for certain room temperature, sticking in a pocky radiator because it suits you doesn't comply.

 

You either take the grant and follow the rules, or don't bother with grant and do want you want. I chose the later.

 

Paying a £6k deposit on a system where you are getting a £7500 grant is questionable.

[nod]

We’ve added SS tall Rads in the bedrooms and four bathrooms But don’t expect to ever use them 

We did the same in our previous build and never used the first floor heating in five years 

The temps seem to track the GH UFH Anyone considering adding UFH to the bedrooms really need to look at the fabric of there build and insulation levels 

[SBMS]

10 minutes ago, JohnMo said:

But they require all habitable rooms to be heated.

This is the real sticking point for us with the installer.  I know that the UFH downstairs can output more than enough to heat the first and probably second floors.  However, it appears that MCS design looks on a room by room basis and as @JohnMo states, each habitable room must have its own heat source.  Even if the likelihood is it will be turned off and heated from below, it doesn't appear a room can 'borrow' the heat output from an adjacent or elsewhere emitter, under MCS Sizing Guidance.

[Rudski]

22 minutes ago, JohnMo said:

To get bus grant the install has to comply with MCS rules. MCS rules should be reviewed. But they require all habitable rooms to be heated.

MVHR is just ventilation - does not contribute to heating, does not move heat about to any degree.

 

So basically the company that hasn't mentioned anything regards individual room heating and quoted us hasn't understood the MCS rules, thanks for the clarification👍

[JohnMo]

5 minutes ago, Rudski said:

 

So basically the company that hasn't mentioned anything regards individual room heating and quoted us hasn't understood the MCS rules, thanks for the clarification👍

Maybe true, but he could also be adding a dose of common sense to the install, so maybe a good company to discuss things with

[Rudski]

Just now, JohnMo said:

Maybe true, but he could also be adding a dose of common sense to the install, so maybe a good company to discuss things with

Not sure I understand, I don't want to end up paying the extra £7500 for the ASHP due to misunderstanding of MCS rules by the installing company, I'm sure to install radiators and pipework to comply with the BUS scheme it wouldn't cost an extra £7500, but I need to understand this up front for budget, or am I not understanding something here? 

[Post and beam]

39 minutes ago, JohnMo said:

They can't as such, the same high temp is generated by the heat pump, if you want a lower temp it's mixed down as well as a high temperature it's done by mixing.

Agree of course but the point is, 'normal' size radiators can be heated to the required temperature. So no need for massive radiators.

 

43 minutes ago, JohnMo said:

Paying a £6k deposit on a system where you are getting a £7500 grant is questionable.

The total project is a fair bit more than either of these 2 figures.

 

44 minutes ago, JohnMo said:

The grant money isn't just for you, it's for future owners of the house also

?

 

45 minutes ago, JohnMo said:

They can at the expense of CoP and actual running costs.

If they are proposing a 45 degree UFH flow temp i dont think this is very high on their priority list. And therefore unlikely to have been foremost in their design.

 

49 minutes ago, JohnMo said:

They have to do a full system design

Yes they do.  This should include the spec of the build and subsequent expectation of heat generation. I believe they are throwing the kitchen sink at the thing. This hints at something other than a competent design.

[HughF]

Just ignore the BUS and install what you want, it’ll work out cheaper.

 

Ashp -> diverter -> ufh manifold

                |—> dhw cylinder

 

Litetally £3ks worth of kit.

 

 

Edited Wednesday at 13:57 by HughF

[JamesPa]

The actual BUS legislation is here https://www.legislation.gov.uk/uksi/2022/565/contents

 

The requirements include "[the ASHP] is capable of meeting the full space heating and hot water heating demands of that property"

 

Note the wording is 'capable of heating the entire property', there is no requirement that every room shall have an emitter (is anyone going to complain if, for example, you don't bother to heat an under-stairs cloak room).

 

The MCS rules here https://mcscertified.com/wp-content/uploads/2021/12/MIS-3005-D-Heat-Pump-Design-Issue-1.0.pdf

 require a heat loss calculation to be done and again that the heat pump is capable of heating the whole property.  I cant find anything in them that says this means you must have an emitter in every room.

 

Of course most designers wont go to the trouble of working out if the upstairs can be heated from heat drifting from the downstairs, and will thus use the regs as an excuse to sell you stuff you may not need.  However so long as it can in fact be heated this way, I cant personally see anything in the regs which prevents you doing it this way.  I would encourage you to read these source documents so you are satisfied yourself what they say.  They are definitive unlike any 'guidance'.

 

I therefore agree with @johnmo that it is worth talking more with the installer who brings a does of pragmatism.  Many installers take the easy route, you perhaps need one that can think outside the box.

 

That said please note that the loss calculation will need to include the upstairs rooms and the downstairs rooms will need additional heating to compensate.  This may actually reduce your efficiency (you have less emitter area so need a higher FT) so may turn out not to be a good idea.  This all depends on your house and its insulation levels, with a new build and UFH the efficiency loss will likely be negligible, and almost certainly less than if you fit radiators upstairs which force the whole system to be run at a higher FT (both boilers and heat pumps can only run at one FT at any one time).  

Edited Wednesday at 14:04 by JamesPa

[JohnMo]

5 minutes ago, HughF said:

Just ignore the BUS and install what you want, it’ll work out cheaper.

 

Ashp -> diverter -> ufh manifold

                |—> dhw cylinder

 

 

Exactly my thoughts too. Especially on a new build.

 

UFH materials less than £1k, 2 or 3 man days to install full house. Panasonic ASHP £2.5 to 3k, cylinder £1k - then install how you want

[Redbeard]

@JamesPa makes a good point. @Rudski, you say:

2 hours ago, Rudski said:

As we are trying to be airtight as possible we thought that UFH downstairs and heated towel rails in the bathroom and en-suite upstairs with MVHR would keep us warm,

 

Have you had a full-house heat-loss calc done? If that shows that the proposed provision (with no rads to bedrooms) *will* achieve the 18/21 desired temps in all rooms then I think you have met the requirement which @JamesPa refers to, as long as the quality of workmanship means that the actual meets the plan. If you are relying on a 'gut feeling' then I guess MCS/the installer do not have to have the same gut feeling as you.

[PhilT]

1 hour ago, JohnMo said:

 

 

Edited Wednesday at 14:15 by PhilT

[HughF]

1946 end of terrace, exposed, on a hill. Upstairs rads are off….you won’t need to heat upstairs 

[sharpener]

Several things occur to me here..

 

Depends on upstairs floor construction. Ours has no insulation, bedrooms get to about 16C without the rads on but even so I wouldn't want to be without them entirely.

 

I have some sympathy with the argument that if public money is involved then the installation should be generally suitable for the property rather than idiosyncratic. E.g. HW cyl should be adequate wrt # of bedrooms. Subsequent owners will after all not be able to get a second BUS grant.

 

If you are going to fit rads upstairs its hardly worth penny pinching on the size at the expense of flow temp as that will hit CoP. I never fully bottomed out what MCS/BRs actually allow but installers won't IME go above 50C flow so the R290 argument is largely irrelevant.

 

I see Cool Energy are now doing an umbrella scheme, their products have not been mentioned on here for a bit but I thought they were well engineered and were quite responsive when I contacted them a while back, might be worth exploring.

 

 

[HughF]

Bumped into Chris from cool energy at installer last year, they’ve got an r290 product out now which although isn’t cheap, does have a lot of functionality.

 

And yes, they offer an umbrella scheme.

 

Still super happy with our old r410a unit, installed in complete contradiction to the manufacturers guidelines 🤣

[SBMS]

The comments relating to the heat loss and UFH being sufficient to heat upstairs… I think it comes down to what tool the installer is using for the heat loss calculations and whether that tool forces the installer down the route of doing it room by room or not. 
 

if asked to evidence heat loss the installer will produce the results of their tool. If tool doesn’t do what we want (ie capacity of GF UFH to heat whole house) then what you are actually asking for is for the installer to source or use a different tool. 
 

that’s the issue as I see it. 

[Rudski]

1 hour ago, Redbeard said:

@JamesPa makes a good point. @Rudski, you say:

 

Have you had a full-house heat-loss calc done? If that shows that the proposed provision (with no rads to bedrooms) *will* achieve the 18/21 desired temps in all rooms then I think you have met the requirement which @JamesPa refers to, as long as the quality of workmanship means that the actual meets the plan. If you are relying on a 'gut feeling' then I guess MCS/the installer do not have to have the same gut feeling as you.

No we haven't had a full house HLC done, we thought that was carried out by the company that is quoting you, obviously with the information provided from myself giving build method windows and MVHR etc, or am I being naive? Should I be seeking an independent survey before approaching these companies? 

 

Again thank you, this is all helping me understand what I should/shouldn't be doing  before i sign on any dotted lines

[Redbeard]

I don't know how renowned the MCS HL calc is for accuracy, but if it is 'within tolerance' and the contractors are quoting to provide 21 degrees to Zone 1 (living room(s) and 18 deg to all other spaces at whatever the low-end assumption is for external temp *without FF bedroom heating* then you are probably OK, and have 'provided (for) heating to those rooms'.

[Rudski]

2 hours ago, JohnMo said:

Exactly my thoughts too. Especially on a new build.

 

UFH materials less than £1k, 2 or 3 man days to install full house. Panasonic ASHP £2.5 to 3k, cylinder £1k - then install how you want

 

That's assuming there is a plumber to do the work or understand how it works in West Cumbria, it's above my knowledge grade, reading of too many crappy instals that have nothing but issues, obviously trying to avoid that. 

[JamesPa]

22 minutes ago, Rudski said:

 

That's assuming there is a plumber to do the work or understand how it works in West Cumbria, it's above my knowledge grade, reading of too many crappy instals that have nothing but issues, obviously trying to avoid that. 

Probably no guarantee that an MCS install under BUS would be any better judging by what we hear.

 

The key things to be vigilant on are

• size it properly, or at least be aware what the correct size is and know if you are deviating and why
• dont allow them to fit a 3 or 4 port buffer, llh or heat exchanger (a 2 port volumiser in either flow or return is fine if needed for adequate system volume).  If anyone suggests it tell them no, and if they wont accept no for an answer, look elsewhere
• dont allow them to fit any external controls which are not specifically designed for heat pumps (which pretty much narrows it down to Homely, so far as I know)
• dont allow fancy 'smart' TRVs to be fitted except possibly in a minority of rooms eg bedrooms.  The majority of TRVs should be set at least 2C above the desired temp, or simply unscrewed so they cant have any effect (or better still not fitted in the first place!)

once its fitted

• balance the radiators
• get the weather compensation set up properly (=minimum flow temp consistent with house being warm enough)

More dont's than dos.  Basically keep it as simple as the system described by @JohnMo

 

The last two you will almost certainly have to tweak yourself, unless the installer is prepared to come back several times.  They take time to work out and this can only be done by experiment in your house.  So either insist your installer shows you how to or read the manual.  Its not difficult, but sometimes installers have a sharp intake of breath if you suggest you are going to do it (even mine did a bit, and he was otherwise pretty good and clearly knew that I knew what I was doing).

 

I cant comment on the Panasonic which @JohnMo has suggested, I have a Vaillant.  Generally it has a good user interface in my opinion (others may disagree).  Ideal are reputed to have a very good user interface, Mitsubishi too (but apparently lacking the ability to do timed flow temp setback, which can be useful).  The UI on some others (including the very popular Samsung) can be a little limited and for my money I would seriously consider getting a homely if you go with one of these that have a more basic controller/UI.  The rest of the heating system matters more than the heat pump itself, but having a decent UI is likely to make it easier to optimise unless you enjoy tinkering.

 

Edited Wednesday at 17:06 by JamesPa

[Rudski]

11 minutes ago, JamesPa said:

Probably no guarantee that an MCS install under BUS would be any better judging by what we hear.

 

The key things to be vigilant on are

• size it properly, or at least be aware what the correct size is and know if you are deviating and why
• dont allow them to fit a 3 or 4 port buffer, llh or heat exchanger (a 2 port volumiser in either flow or return is fine if needed for adequate system volume).  If anyone suggests it tell them no, and if they wont accept no for an answer, look elsewhere
• dont allow them to fit any external controls which are not specifically designed for heat pumps (which pretty much narrows it down to Homely, so far as I know)
• dont allow fancy 'smart' TRVs to be fitted except possibly in a minority of rooms eg bedrooms.  The majority of TRVs should be set at least 2C above the desired temp, or simply unscrewed so they cant have any effect (or better still not fitted in the first place!)

once its fitted

• balance the radiators
• get the weather compensation set up properly (=minimum flow temp consistent with house being warm enough)

More dont's than dos.  Basically keep it as simple as the system described by @JohnMo

 

The last two you will almost certainly have to tweak yourself, unless the installer is prepared to come back several times.  They take time to work out and this can only be done by experiment in your house.  So either insist your installer shows you how to or read the manual.  Its not difficult, but sometimes installers have a sharp intake of breath if you suggest you are going to do it (even mine did a bit, and he was otherwise pretty good and clearly knew that I knew what I was doing).

 

I cant comment on the Panasonic which @JohnMo has suggested, I have a Vaillant.  Generally it has a good user interface.  Ideal are reputed to have a very good user interface, Mitsubishi too (but apparently lacking the ability to do timed flow temp setback, which can be useful).  The UI on some others can be pretty basic and for my money I would seriously consider getting a homely if you go with one of these that have a more basic controller.  The rest of the heating system matters more than the heat pump itself, but having a decent UI is likely to make it easier to optimise unless you enjoy tinkering.

 

Many thanks for this information, it definitely arms me with some questions to go back with, such a variation of size of units and water storage etc, between two companies alone set the alarm bells ringing one quoting for 8.5 kw one for 5 kw! Both given same information, i think i need to go and do a bit more revision😃 

[Rudski]

1 hour ago, JamesPa said:

dont allow them to fit a 3 or 4 port buffer, llh or heat exchanger

Can I ask what this means please, and why the alternative suggested is a better option?  In simpleton terms😃

 

thankyou

Edited Wednesday at 18:02 by Rudski

[Chanmenie]

4 hours ago, HughF said:

Just ignore the BUS and install what you want, it’ll work out cheaper.

 

Ashp -> diverter -> ufh manifold

                |—> dhw cylinder

 

Litetally £3ks worth of kit.

 

 

Not always, I had a Veismann Vitocal 151a installed, so that’s ASHP and internal unit with tank, buffer, pumps and all valve etc for £1800 

You can’t even buy a good heap pump cyclinder for that let alone the ASHP itself