Okay so the British Summer time is over, autumn is almost over, Christmas lights are on, and Scotland has had the first proper cold snap. The temperature yesterday never rose above 2°C despite the sun, and it went down below zero two nights in a row. So how is the new ‘heat pump challenge’ going?
Rather well, so far. By not turning the heating off at night and instead lowering the thermostat setting only by a couple of degrees, the flat is kept warm(ish) all night, so it doesn’t take long to bring the room temperature back up even at a flow temperature as low as 45°C.
Even though the 25-year-old, single panel/single convector radiators seem feeble, they appear to be emitting enough heat in most rooms, and the walls and windows are not losing too much heat.
The only room that may require some upgrading is the living room, which is unusually large, with a large bay window with a French door – an attractive feature but clearly the main route for heat loss. When the door is closed to cut off the heat coming from the radiator in the hall, you notice the living room getting slightly cooler than the rest of the flat, especially near the window. Perhaps replacing the radiator at the window end of the room with a double panel type may help?
But all in all the result so far has been very encouraging, and I will reduce the flow temperature gradually throughout the winter to see how far I can take it. The boiler spec says the minimum setting is 35°C, so there’s still room to go further.