Greetings from a noob!
We live in the Denver suburbs (~5800 ft elevation) in a 3600 sq ft home, built in 1989. It's single zone, and we still have the original 170K BTU furnace. The gas valve has gotten stuck a couple of times, and I'm thinking we are probably due to replace the furnace. I'm working at getting some proposals, but have one so far. The guy that came out to look at the stuck valve gave me a bid for a 135K BTU 80% efficient Lennox. I've looked on-line (including a cursory search here) and now have some questions:
Steve
We live in the Denver suburbs (~5800 ft elevation) in a 3600 sq ft home, built in 1989. It's single zone, and we still have the original 170K BTU furnace. The gas valve has gotten stuck a couple of times, and I'm thinking we are probably due to replace the furnace. I'm working at getting some proposals, but have one so far. The guy that came out to look at the stuck valve gave me a bid for a 135K BTU 80% efficient Lennox. I've looked on-line (including a cursory search here) and now have some questions:
- I'm not completely sure we have room in our furnace room, but if we do does it make sense to consider two dual furnaces (smaller, but maybe more efficient) instead of a single one? What are the tradeoffs?
- The guy guessed that my current furnace is something like 60% efficiency, and I have no reason to doubt that. If that is correct, then a new 135K BTU at 80% is pretty close to the 170K BTU at 60%. Does 60% sound like what a 1988/1989 furnace might be?
- This contractor also said that we probably needed a DC motor blower to move more air in such a large house. I'm an electrical engineer, but I deal mostly with computer electronics. Still, I'm not sure I get why a DC motor would be better, and I can't see that the lennox he is bidding has a DC motor. Any thoughts?
- I know we don't talk price here, but I sure have lots of those, and I will have more once I get more proposals!
Steve