Can I specify that my installer uses my own 'Heat Punk' Heat loss Calculation for a BUS Grant Installation?

Home Retrofit
1

Hi,

This is my first post, so please be gentle with me !

I want to install an ASHP, using the BUS Grant.

I’ve had lots of different ‘suggestions’ about my Heat-loss, so I decided to do my own calculation, using the MCS-approved ‘Heatpunk’ system.

We live in a Victorian property that has been heavily renovated, including triple-glazed Doors & Windows throughout.

If I tell Heatpunk that those renovations bring our house to a post-2000 level of insulation, it gives a figure of 6144W for space heating, whereas if I tell it that the same specifications only bring it to a ‘Pre’-2000’ level of insulation, it gives a figure of 8455W

I am happy to go with the lower figure, as I am aware that under-sizing is generally less of a problem than over-sizing, and Samsung do an 8kW that nearly meets the higher figure, anyway.

But my installer has the higher figure, and so feels he can only install a much bigger (12kW) unit, as that is the next size up in the range … (Samsung R290)

So, to put it simply, can I ask him to use my figures and install the smaller 8kW unit, - and if he does so, will MCS have a problem with that, and stop him receiving his £7,500 BUS Grant ?

Thanks !

2

Welcome to the forum @tokenpom .

You are correct that oversized systems are more problematic than undersized. Particularly regarding lifetime cost.

My experience is that an MCS installer should follow procedures and make judgements according to their experience. There isn’t a facility to believe the person who ought to know the property better than any other, the homeowner.

I was lucky to find an installer that accepted my figures but that is a rarity. You may have to look for another installer.

Various installers came up with a range of figures based on the assumptions they made. I then declined them and moved on.

3

Thanks Tim !

Yes, I’ve found that if you don’t live in a bog-standard, modern 3-bed semi, and need something a bit more ‘bespoke’, you do end up having to ‘kiss a lot of Frogs’ … ! LOL !