Basically, the computer will be very nearly as efficient as a regular resistive electric space heater, but the building is almost certainly not being heated tha

Basically, the computer will be very nearly as efficient as a regular resistive electric space heater, but the building is almost certainly not being heated that way. Heat pumps are far more efficient than resistive heating. http://physics.stackexchange.com/a/1494 http://physics.stackexchange.com/a/1494 (The building may also be on district steam heating, fuel oil, possibly even coal, any of which could be cheaper than electricity, depending on location.)