RHI not allowed if not all rooms are heated by ASHP...true or false?

[Thorfun]

I had an interesting conversation with a renewables company that said that if I wanted to claim RHI payments then every habitable room in the house needs to be heated by the heat source, ie. ASHP in our case. I asked about Passivhaus properties where heating upstairs might not be required and was told that if a room is not heated by the heat source then the property doesn't qualify for RHI.

 

does anyone who can disseminate the minefield that is RHI let me know if this is correct? sounds like a crock of excrement to me and they're just trying to sell me UFH on the first floor in order to some RHI payments.

 

I still haven't decided if I'm going down the RHI/MCS route yet for ASHP (or Solar PV) but I was generally thinking of not having UFH in the bedrooms and having electric UFH and towel radiators in the en-suites on the first floor. and wet UFH from an ASHP in the basement and ground floor. so if I did go for RHI then the electric heating and lack of heating in the bedrooms was mean we wouldn't be elligble anyway. 

[joth]

I had 2 detailed quotes (and about 4 price indications) for my passivhaus retro fit with down-stairs only ASHP heating and none of these installer mentioned this requirement. This is with us having direct-heating in the upstairs bathrooms, and none in bedrooms.

 

Check page 24 of https://www.ofgem.gov.uk/system/files/docs/2018/07/essentialguideforapplicants_july_2018.pdf possible confusion:

- If you have "Backup heating" (including hybrid ashp/gas boilers) you DO need metering for payment. (But can still claim RHI, so long as you submit those meter readings)

- Any backup heating source(s) that only warm a single room (such as portable electric heaters, or indeed my bathroom UFH mats & towel rails) do not trigger the above clause so metering for payment would not be needed.

 

(Interesting that guide doesn't have a peep to say about needing metering for payment if the ashp supports cooling, which one installer claimed was the case. This makes total sense as any active cooling will not have any impact on the accuracy of room-by-room heat loss estimate of heating demand from the ASHP)

 

 

[Thorfun]

16 minutes ago, joth said:

I had 2 detailed quotes (and about 4 price indications) for my passivhaus retro fit with down-stairs only ASHP heating and none of these installer mentioned this requirement. This is with us having direct-heating in the upstairs bathrooms, and none in bedrooms.

 

Check page 24 of https://www.ofgem.gov.uk/system/files/docs/2018/07/essentialguideforapplicants_july_2018.pdf possible confusion:

- If you have "Backup heating" (including hybrid ashp/gas boilers) you DO need metering for payment. (But can still claim RHI, so long as you submit those meter readings)

- Any backup heating source(s) that only warm a single room (such as portable electric heaters, or indeed my bathroom UFH mats & towel rails) do not trigger the above clause so metering for payment would not be needed.

 

(Interesting that guide doesn't have a peep to say about needing metering for payment if the ashp supports cooling, which one installer claimed was the case. This makes total sense as any active cooling will not have any impact on the accuracy of room-by-room heat loss estimate of heating demand from the ASHP)

 

 

thanks @joth. I will read through that document in detail.

 

I also have had a couple of other quotes and neither of those companies have said that all rooms need to be heated so I think these guys are wrong (or simply mistaken), as your research has showed.

 

what I'm also finding is that the MCS/RHI heat loss calculations are shockingly bad! I've used @Jeremy Harris 's spreadsheet and it comes out at worst case scenario an 8kW ASHP @ -10oC. but all the MCS installers have said I need a 14kW ASHP! after speaking to one of the installers we figured out that the RHI heat loss calculations don't take in to account the efficiency of the MVHR. once he added that in my requirements suddenly went down to 5kW @ -2oC. that's a big difference.

 

I'm seriously looking at forgetting RHI for the small amount we'd get and just getting a plumber to install the ASHP. for a highly insulated and air tight building the RHI just doesn't make sense. it would be better for me to aim for a lower SAP rating to get more from RHI rather than spending money to get a high SAP rating. just seems completely balmy and backwards to me.

[Declan52]

Don't forget the company during the MCs work have had to pay to register on the scheme. This will bump their costs up by a tiny amount so will obviously pass this cost on x5 at least. The bigger the ashp you buy from them the more expensive it will be so the more money the will make on it. 

If you have all your drawings and intend to build to that spec then get a sap report which will tell you your heat demand. Will be a lot cheaper than over paying for a larger ashp.

[Thorfun]

Just now, Declan52 said:

Don't forget the company during the MCs work have had to pay to register on the scheme. This will bump their costs up by a tiny amount so will obviously pass this cost on x5 at least. The bigger the ashp you buy from them the more expensive it will be so the more money the will make on it. 

If you have all your drawings and intend to build to that spec then get a sap report which will tell you your heat demand. Will be a lot cheaper than over paying for a larger ashp.

 

understood and agreed. I am already paying for a full thermal modelling report which I'm hoping won't be too far away so I will have those head demand calculations soon. until I get those though I'm working on the results from Jeremy's spreadsheet which all seem to say are pretty darn accurate!

 

I'm still waiting for a couple of companies to quote but at the moment it's looking like RHI just isn't worth it.

[joe90]

45 minutes ago, Thorfun said:

I'm seriously looking at forgetting RHI for the small amount we'd get and just getting a plumber to install the ASHP. for a highly insulated and air tight building the RHI just doesn't make sense. it would be better for me to aim for a lower SAP rating to get more from RHI rather than spending money to get a high SAP rating. just seems completely balmy and backwards to me.

Why quote a few of us didn’t bother with RHI.

[Thorfun]

Just now, joe90 said:

Why quote a few of us didn’t bother with RHI.

yeah. that's what I gather from the reading I've been doing. I have a neighbour who is a plumber so I'll be popping around to see him and ask about DIY installing the ASHP. as with anything it's only the lack of confidence and not wanting to screw it up that is holding me back from just doing it all myself. that and I want the house to be finished before 2030. ?

[joe90]

1 hour ago, Thorfun said:

and I want the house to be finished before 2030.

And me, I got a plumber neighbour to help me do mine.

[joth]

Yup. We had 2 heat loss calcs done for MCS and both came in well over twice the peak heating load that PHPP reckons. They tend to assume worst case on airtightness and one ignored our stated U values too.

 

On the plus side, as a retro fit we could install the ASHP against the old EPC which makes it almost worth it. But GHG avoids that hoop jumping too.

 

[Thorfun]

55 minutes ago, joth said:

Yup. We had 2 heat loss calcs done for MCS and both came in well over twice the peak heating load that PHPP reckons. They tend to assume worst case on airtightness and one ignored our stated U values too.

 

On the plus side, as a retro fit we could install the ASHP against the old EPC which makes it almost worth it. But GHG avoids that hoop jumping too.

 

GHG is on my research list too. Just one of many subjects on a very long list!