Hi all,
just bought a 1965 house has a cavity wall insulation and a 30 year old boiler, it needs a full refurb the only thing it don’t need is to be bulldozed down and re built that’s how big the project is, anyway it’s our first home and wanting to make it a home so we want to install underfloor heating system on both floors.
Upstairs and downstairs are both suspended floors on.
downstairs I was planning on putting 100mm insulation this is the most we can put and that’s us having to pull the joists out and put bigger ones in then have UFH fitted on that
upstairs I was going to have 75mm insulation in joists and electrics below the insulation and UFH Above of course. The attic is fully insulated aswel I believe with 75mm insulation but this isn’t a problem too much if needs more
Downstairs the plan is to have a two port(zone) valve, pump, 5 port manifold, and electrics and upstairs is another two port (zone valve), pump, 4 port manifold and electrics reason for this is mainly peace of mind and more control the zone valves will be teed of coming from the boiler!
The house is 42square meter per floor totalling 84 square meter maximum of UFH Ofcourse showers and other fixtures like that will reduce amount of square meter available but let’s work to the 84 square meter, we’ll be running 16mm pipe at 200 pipe centres 2 in between each joist. And I’m pretty happy this is all possible and fitted but something thrown a spanner in the works that might scrap it, as we need a new boiler plan is to get a combi, what size combi boiler do I need for the 84 square meter ? The one I was looking at was the Worcester Bosch 8000 life but not sure what the kW as the 35 law and higher all output 35kW of heat would this be enough or am I going to have to go into fitting a different type of boiler ?
I understand the downside of a combi boiler when someone is showering and stuff the heating is turned off but I think since the rooms will be well insulated this will be ok.
so going back to the question is a 35kW heating output combi boiler enough for 84 square meter UFH ??