If you are doing it for the environment, you should forgo heat. 100F to 70F is only a 30 degree delta. If you have a heat pump, this is the same amount of energ

If you are doing it for the environment, you should forgo heat. 100F to 70F is only a 30 degree delta. If you have a heat pump, this is the same amount of energy heating your home to 70F from 40F. If you have natural gas heating, now we are talking about the same amount of energy when it is low 50's outside. How many forests will you burn to not just wear two sweaters and blanket?