18-11-2020, 01:05 PM
TRVs are a somewhat cheap and nasty solution to regulating individual radiators. Much better to have a separate thermostat in each room operating an electrically actuated valve. There are also "smart" heads for TRV such as these: https://heatingcontrols.honeywellhome.co...lled-TRVs/
Even better is to have a home that well enough insulated so that you don't need a central heating system at all. Minimal fuel bills and win back all that space lost to radiators. That's what PassivHaus is all about: https://passivehouse.com/ It's not the only approach to low energy houses but it's well established. It's much harder to uprgade an existing house to that sort of standard than it is to build from scratch.
I know this is dragging things a bit close to politics, but there have been major "green" policies announced today by HMG. As a roadmap it's fair enough but there's a lot of missing detail. One thing stands out to me. There's a push to move from gas boilers to heat pumps for domestic heating. Unless you dramtically upgrade insulation the numbers don't work. If you have gas at about 3p/kWh and replace with a ground source heatpump with leccy at about 14p/kWh you need a COP of over 4 for the heatpump to break even. That's a tough ask. Coefficient Of Performance is kW of heat out per kW of leccy in. 3 is a reasonable result. Also Heatpumps work much better with lower radiator temperatures thatn normally used with gas boilers. So you need bigger rads. They are well matched to underfloor heating with its lower water temperatures.
If your insulation is good enough then your carbon usage drops anyway. So I'm really not sure that heatpumps are a panacea.
Even better is to have a home that well enough insulated so that you don't need a central heating system at all. Minimal fuel bills and win back all that space lost to radiators. That's what PassivHaus is all about: https://passivehouse.com/ It's not the only approach to low energy houses but it's well established. It's much harder to uprgade an existing house to that sort of standard than it is to build from scratch.
I know this is dragging things a bit close to politics, but there have been major "green" policies announced today by HMG. As a roadmap it's fair enough but there's a lot of missing detail. One thing stands out to me. There's a push to move from gas boilers to heat pumps for domestic heating. Unless you dramtically upgrade insulation the numbers don't work. If you have gas at about 3p/kWh and replace with a ground source heatpump with leccy at about 14p/kWh you need a COP of over 4 for the heatpump to break even. That's a tough ask. Coefficient Of Performance is kW of heat out per kW of leccy in. 3 is a reasonable result. Also Heatpumps work much better with lower radiator temperatures thatn normally used with gas boilers. So you need bigger rads. They are well matched to underfloor heating with its lower water temperatures.
If your insulation is good enough then your carbon usage drops anyway. So I'm really not sure that heatpumps are a panacea.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
