The recent cold snap, and corresponding increase in our heating bill, has meant that I’ve looked at using radiator reflectors at home. These are panels, made of reflective material, which go behind your radiators and reflect heat back into the room.
Unless you’re lucky enough to have under-floor heating, if you have central heating then your heat will most likely come from radiators hung on your walls. The heat from these radiators literally radiates out in all directions, which means that some of this heat will be going into the walls behind your radiator. Radiator reflectors redirect that heat back into your room, increasing the efficiency of the radiator.
Radiator reflectors are especially useful for radiators on external walls, as otherwise you’re potentially allowing heat to escape outside the home. Our house is around 100 years old, and we’ve been told that we can’t have cavity wall insulation, so heat loss is an issue for us.
Choosing radiator reflectors
The radiator reflectors that I bought are Radi Save from Must Have Ideas. Instead of individual panels, you get one five metre long strip of material, which you then cut down to size. Thankfully, the four radiators that I wanted to add reflectors to added up to 5.1m, so one pack was adequate; if I was to do the whole house, then two would have probably been sufficient. Each five metre pack normally costs £20, but they’re on offer for £15 each at present, plus postage.
The material is easily cut with regular scissors – you just need to measure the radiator’s width, knock maybe an inch off each end, and cut it to size. You also need to measure and cut out holes so that it can slide around the brackets. Then, just drop it in place behind the radiator, assuming your nine-year-old hasn’t filled the back of the radiator with various dropped toys. You can then attach them to the wall with double-sided tape, if you wish; I haven’t yet, as it gives us the option of storing them over summer when the radiators are off.
The market leader seems to be Radflek (sponsored link) – they will sell you panels and a kit to hang them from the radiator brackets. A pack of two panels costs £20, so they’re a little more expensive than Radi Save. However, as you would expect, there are many other radiator reflectors on sale from Amazon, including similar products to Radi Save.
Do they work?
As I write this, I have installed our radiator reflectors on two radiators – one in our bathroom, and the other in our dining room. Our bathroom radiator is small, and behind a door, and this is where we’ve seen the most benefit. The room doesn’t feel as cold as before, and there’s been less of an issue with condensation on the window since I fitted the radiator reflectors.
Also, I believe the previous owners of the house used to have a gas fire in the bathroom, where the radiator is now, however the old flue from the gas fire remains. As such, some of the heat from the radiator was being channelled out of the house through the flue. The radiator reflector seems to be preventing this now, which is great – indeed, the back of the reflector, facing the wall, was almost cold even when the radiator was on.
So yes, it feels like they’re working. I can’t back this up with my own solid data, but most product pages selling radiator reflectors seem to include images taken from thermal imaging cameras to show that they work.
Do they save money?
£15 for four radiators doesn’t seem like much, but it’s still an investment. Whether you will save money by using radiator reflectors will most likely depend on whether you have thermostatic radiator valves (TRV). These are valves on your radiator that open and close in response to how warm your radiator is; once your room is warm enough, the valves will close up and will reduce the flow of hot water into the radiator. As mentioned, radiator reflectors help by increasing the efficiency of the radiator, theoretically meaning that the radiator will warm up faster, and so that the TRV can close up sooner.
We have standard TRVs on our radiators, but it’s possible to get smart TRVs. These can be set to a specific temperature, using an app, and, if they’re from the same brand as your thermostat, can control your boiler or heat pump too. If not, then it’s possible to rig something up with Home Assistant.
If you don’t have TRVs, that doesn’t mean that you won’t save money – certainly, if you add a reflector to the radiator in the room where your thermostat is, you should still save some money. But hopefully you’ll find that your rooms are at least warmer than they were before, without burning more gas.
Can’t I just use kitchen foil?
I’ve long been aware of the suggestion that you just put some kitchen foil behind your radiators, rather than buying dedicated radiator reflectors. According to this web page, kitchen foil may work, but it isn’t likely to be as effective. It’s delicate, so tears easily, and isn’t as insulative as proper radiator reflectors.