As some of us enter Winter, here're some calculations on true cost of mining

[vapourminer]

depends on you heating cost.. if you get heat cheap enough with your normal HVAC system you still lose money heating with old tech ASICs and/or GPUs.. just not as much. loss is loss.

I would lose money big time heating with my GPU and 65 nm ASIC stuff vs my geothermal HVAC.