Log Biomass Boiler System

captainhindsight_2

villabadger wrote: »

Hi

I've not yet had a green deal assessment but to satisfy my curiosity I have had an EPC done. The figures are:
Space demand (kWh per year) = 61,358
Water demand (kWh per year) = 3,169
Impact of loft insulation = (4,715)
Impact of solid wall insulation = (19,978)

At first glance it appears that I would need a 65kW boiler but if I can prove that the house is properly insulated then does this mean that only a 40 kW boiler would be needed? is this how it works?

I have loft insulation in the house but an attached building (still considered part of the house) still needs doing, which is not a problem. The walls are stone constructed and approx 2 ft thick with lathe and plaster 'skin' on the inside of each outside wall. This obviously creates an air gap. Is this considered as insulated, even though no modern material is installed? Or would I still need to fit insulated plasterboard to satisfy the requirements?

The house was built around 1850 (not listed) and the front elevation still has very large sash windows which are single glazed. To me, most heat loss would be through these. Would the demand be significantly affected by not replacing these, as there is not a calculation specific to this?

Any ideas?

Thanks

Based on those figures looks like you need a 40/45kw boiler, the boiler size is calculated by dividing the heat demand by 1314

All you need to do is sort out the loft insulation.

The windows will always be your biggest heat loss regardless of what you fit, and the solid wall insulation will help but is not a requirement to get the Rhi.

I am sure you are already aware that the Rhi is dropping 1st April but is probably too late already now if you want a premium boiler like frolling as they take 4-6 weeks to be delivered however cheaper boilers but still very good boilers like red, Domusa, wind hager etc usually around 2-3 weeks

villabadger

Thanks for your reply. I had missed that divide by 1314 even though it is on the RHI calculator that I have been using!

Unfortunately I am not going to be ready to beat the RHI reduction as I've still got to re-roof the outbuilding where the boiler and storage tank will be installed - that's an expensive mistake on my part as that will be a loss on return of approx £10K over 7 years!! Got to make sure that I beat the next review in 3 months time.

Thanks again.