Both this and SIP’s Fireball 35 use 3kWh of power and behave very similarly. But in virtually every way, the Clarke unit trails the Fireball. The warm-up time is seven seconds slower, at 50 seconds, the heat gain was 1oC less, and the warmth can’t be felt as far away, either. Not a bad model, but it hardly provides the instant intense heat which radiants are supposed to.