While yes a heater might be more efficient at spreading the heat into the room, last time I checked the heater only has a few settings a low, med and/or a med/high setting. I have a unit at home, low uses roughly 850W, high is closer to 1300W. Thats the heating element + fan. Extra up to 60W if I want the fancy fire place look. It does a very good job heating a room, I don't disagree with that. Though if you don't need all that heat (yes most can have a set point in temp and turn off and turn back on when needed) but you can use a PC to do similar. Its not going to blow air efficiently into the room I will agree with that but, its lower wattage if you have concerns on your power consumption and if you use it does work. That being said if your mining with it not only are you making heat, but your making money no mater the electric cost. Only reason I say that is last time I checked a space heater doesn't have a form of making money just using it