[Barrie Yates]

Originally Posted by Gordon Booth

MargaretR, it takes a certain amount of energy to heat a room.Whatever system you use it will take the same amount of energy(gas?) to bring your room to the required temperature. IF the booster makes your radiator 50% more efficient the water going back to your boiler will be colder therefore your boiler switch on more(although the room COULD heat up a little quicker). The radiator is already a convector, so a fan(which blocks off the top of the radiator and therefore stops the NATURAL convection) can't help a lot. And how can it stop heat going into the wall? That's already happened before the hot air reaches the top where the fan is! Also if it costs 30p/year(thats 3 hundredths of 1 penny/day) to run, its not using enough electricity to light a glow-worm so you're not getting a blast of hot air, are you? Also your £17 will buy you a lot of heat.
If you turn your thermostat down 2 degrees then your room will be 2 degrees colder,logical.
Mattylads ideas will save you a lot more, put turkey foil behind your radiator if it worries you.

If you can get foil faced polystyrene sheet and put that behind your radiators it is even better than just aluminium foil. With this device you have to take into account the electricity used for the fan. An insulator/reflector and a shaped shelf over the radiator will give you just as much an increase in heating per pence - probably more.