I have a 2 family home with an oil fired furnace heating and providing hot water to the apartment on the 2nd floor. The system is currently costing me approx. $3,500 a year for a 1,100sf apartment and its killing me. It consists of a single pipe steam system and I’m really not sure how old the current furnace is because the house was a foreclosure. I do have two gas meters in the house and the gas is going up to the second floor for the stove. I’ve had a few HVAC contractors come in and give me estimates on converting from oil to gas and it seems like putting in a natural gas warm air furnace in the attic is the least invasive and my best bet but I’m getting conflicting information.
Contractor A quoted me on a Carrier 80% AFUE Natural Gas furnace with evaporator coil and a 40 gallon hot water heater. He states that 80% AFUE is the best efficiency I can put in my unheated attic (I live in Rhode Island) because of the condensation more efficient units create. Contractor B quoted me on a Tempstar 92% AFUE and a 40 gallon hot water heater. When I questioned him on the condensation issue he stated that he will insulate and heat trace the drain line along the gas line he runs into the attic.
I like both contractors and they both rate well with the BBB, but who do I believe? I’d like to get as energy efficient as possible. Just in case your wondering about the insulation in the attic, I currently have 12” of older batt insulation and will be blowing more in once the heating system is in place.
Thanks for any advice!