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Ideal Logic ASHP - change from 55°C to 35°C Heating?
Ok on second thoughts scrub the questions. Id be tempted to optimise the rads as previously described. If you find that this results in a rad curve lower than 0.8 (IE the rads can run at a lower temp than the ufh), assess what to do with the ufh. If there is scope to run it at lower ft do so otherwise this will be the limiting factor. It would be quite unusual however for rads to be sized so they need a lower ft than ufh.
4kW peak of solar PV since 2011; EV and a 1930s house which has been partially renovated to improve its efficiency. 7kW Vaillant heat pump.
Agree - I will finish optimising the rads before I think about the UFH
UFH temperature is adjusted with the mixing valve located on the manifold. It's currently set at 50°C which is the max setting but can be dialled down if needed. The speed of the pump can also be tweaked to increase or decrease the flow rate. The flow meters can also be adjusted for each loop if needed but fully open up when the UFH is on.
I've now opened the rad TRV's to max and will monitor the heating performance over the coming days.
UFH should never be at 50C since small feet can get burned. I think the regs say 39(?). But your floor covering could be damaged too unless it’s tile or concrete. Nobody want pipe shaped marks on their wood or blown adhesive on LVT.
2kW + Growatt & 4kW +Sunnyboy PV on south-facing roof Solar thermal. 9.5kWh Givenergy battery with AC3. MVHR. Vaillant 7kW ASHP (very pleased with SCOP >4) open system operating on WC
Good point. I’ll keep my eye on the manifold temperature gauge which is currently showing 30C with the room temperature currently at 19C. After changing the heat curve yesterday from 1.5 to 1.3 the heating flow temperature has reduced from 50C to 45C. I’m not sure the UFH would ever reach the same temperature as the flow but best to keep my eye on it to prevent the issues you have mentioned. Thanks for your help. It’s great to learn from others, especially through forums like this one
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