I've got a buddy that heats his house with one 7500 watt Farenheit heater with a built in fan. his house is a one level two bedroom home, 28X34. he has the heater mounted in the basement and has the basement door open all the time. he has another small 1250 watt oil filled heater in his kitchen(center of the house)to help with the 10 degree and colder days. his house stays 64-66 all winter. it adds $100.00-$125.00 a month to his electric bill, but it's still cheaper than LP or fuel oil. I've got a wood stove in my shop 60X100.