Zentachi

2 radiators will be added and 2 will be replaced (upsized). Total around 24,000BTU in the ground floor if I counted correctly. Currently the u-value of the suspended floor with the rockwool is around 0.3W/m2K if I add 25mm Kingspan Kooltherm K103 it will bring it down to 0.22W/m2K. Will that a good improvement? Even if UFH will be a bit less efficient, I don't mind sacrificing it for more convenience and comfort!

Thank you for the info. Wunda had a calculation based on 70W/m2 but I was planning to have run with low flow temperature like 30-35C. I agree but in my case each zone will have it's own loop. I was afraid that maybe this isn't the best approach. So maybe I will check to with having two zones. I have hoped the insulation was sufficient enough. Unfortunately the heat pump installer doesn't do UFH so maybe I should just stick with radiators.

hi everyone, I have had a survey to install a heat pump with the results as following: - Total Heat Loss (total) 5.2kW - Heat pump proposed 6kW (Daikin) In addition, I am thinking that maybe now is a good time to convert the ground floor to UFH (two-storey) . For a floor area of 40sqm, will need a 2.8kW load assuming 70w/sqm Suspended timber floor with 100mm rockwool insulation most of the ground floor. Exemption the kitchen with concrete slab (5.2sqm out of the 40sqm). Will UFH work well in my setup? Thinking of having 6 loops (zones). Which one should I go with? Wunda or Nu-heat? Retrofit so it will be between Rapid Response and LoPro, respectively. Thanks, Zen

Many thanks! Coat cupboard sounds like a good idea. I was thinking of having the manifold in there as well. As for smart controls. most probably I will go with tado https://support.tado.com/en/articles/3487152-how-does-tado-control-multi-room-heating-setups-with-a-combination-of-radiators-and-water-based-underfloor-heating and something along the lines of option no 2. Looks pretty straightforward.

Hmmm thanks for the photo, very helpful. This makes me think that such a buffer tank will fit. Can it go to the space under the boiler or does it need to be fitted high?

Thanks Nick for your advice. I don't think I will be able to use a buffer tank, but I will have another look and try to include it. Walls are insulated, however not the floor so this will be part of the process. It is suspended timber floor and most probably I will use PIR for insulation. Definitely I will keep reading the various threads to find useful information

Hi everyone! Nice to meet you. Just bought my first property, a 1930 semi detached two storey house. I am planning to retrofit wundatherm underfloor heating on the ground floor and leave radiators on the upper floor. The house has a combi boiler. I want two zones so the radiators will work independently of the UFH. What is the best way to connect them? Is just a zone valve before the manifold enough? Most probably I will get the Honeywell evohome or the tado V3 smart thermostat. Anyone had the above setup and use any of these smart systems? Many thanks, Zen