> because far more efficient electrical heaters How are you defining efficiency here? Efficiency is usually defined as (useful power out)/(power in), and basi

> because far more efficient electrical heaters How are you defining efficiency here? Efficiency is usually defined as (useful power out)/(power in), and basically all the power that goes into a computer comes out again as heat, which in this case is considered useful. Not really convinced you could buy a heater that was measurably more efficient. ETA: heat pump would do it, didn't spring to mind when I read heater though!