I've no central heating and am looking for any recommendations for portable heating. No rooms are massive, but they're all double height ceilings (or close enough for jazz) - and we're talking single glazed sash windows.
I've got a blow heater, but that's fairly heavy on electricity use and visitors find its heating power...well..."meh" to say the least - so, which is best; radiant? Convection? Are oil filled jobbers the bee's knees or does that accolade go to halogen? I'm after economy and efficacy.
Oh and Calor gas isn't an option.