My thoughts were to see if it would work first by testing it with the garage. If it was successful then start using it to help heat the house.
I'm using a 1500 watt portable heater in the garage now that keeps it nice and comfortable at 58*F to 62*F even when its -10*F outside. Keep in mind I work out in the garage two hours every night.
Our total electric cost house/garage last year during the month of January was $74.00 with the electric garage heater running, thermostat controlled.
Our gas was $87.00 for the month of January This is what heats our house and the water heater, stove/range is electric.
So the gains would be very small I know.
So this project would be more about how warm would the garage get 20 x 20 x 8 ft. ??? Would it be feasible to integrate it into the house heating???
It just bugs the living day lights out of me knowing that my truck could possibly be a extra heating source since its used for delivery 8 hours a day.