Adding UFH to existing boiler

[makingprogress]

Hello, thanks in advance to anyone that can help.

 

We live in a 1910 semi-detached and are planning the following phases of work:

1) Rear kitchen extension and opening up rear kitchen and dining room, with a slab and underfloor insulation. Underfloor insulation front of ground floor in hall, utility and lounge. New windows (triple downstairs). Chimney removal. MVHR system installed. Solar on extension

2) Internal wall insulation on external walls (woodfibre, mostly 50mm to save space). Bathroom refurb. New radiators and ASHP. Battery.

3) New velux windows in loft, internal wall insulation in loft (if needed).

 

The phasing is part budget, part building logic.

 

I am hoping we can use our current boiler to serve the UFH (approximately 40m2) as well as our current radiators. And then next year, once we have the internal wall insulation, we can fit the ASHP.

 

The boiler is a Greenstar24Ri. 

 

How do I work out if this is possible? I am assuming it's just maths, and I need to work out the KwH or the UFH, the radiators that will remain, and the hot water system...is that correct? And if so, how do I work out the KwH of each of them?

 

And if that's not correct...please help!

 

Thanks

 

 

 

 

 

 

[JohnMo]

You don't really need have to work out the kWh, you need you understand the kW required - the power.

 

The boiler is already way bigger than most heat pumps, so not seeing much issue.  

 

To understand better you need to do a heat loss calculations for the final layout of your house. There is spreadsheet in the boffins corner that's quite good.

 

Tying it into the existing system is pretty straightforward. Here is the advise from Bosch using close coupled tees.

 

CCT WORCESTER BOSCH.pdf