I’ve got a mini oil fired radiator, 650w, which costs about 22p per hour to run now. It’s got good reviews, and is excellent, you can move it easily and it keeps one room warm, if you’re cold when you first switch it on, you can move it so it’s closer to you. It’s also silent, I don’t like convection heating because it’s too noisy.
Unused rooms, heat storage and heat transfer
Burnham: Is the Media Tempting Fate by Jumping the Gun?
