Thanks guys.
73 I don't think it gets below 35 that often in northern bammer, although the last two winters are an exception.
What makes the dual fuel very attractive is the fact that Huntsville Utilities has a very nice rate for electricity but a bad rate for natural gas. Thus I am tempted by the dual fuel, but (a) it would take a long time to pay for itself and (b) I don't know that I will be in this residence for the next 10 years.
I have a 1964 house that is fairly well insulated and has shade trees on the afternoon side (was designed that way I am sure). I have UV-blocking windows in all but a small bathroom window that faces northeast. I do have a large glass sliding door in the kitchen that is not UV-blocking but that's probably the largest heat sink. Well, that and my pet door to the garage.
My house is 1722 feet split level. One comment I have had from an estimator is that I probably should have a return upstairs. He claims it's a strain on the system not to. My only return is centrally located downstairs. It's great for downstairs but I agree I need another return. I can hear the system straining at times.
So far only Sears and Home Depot have submitted bids. A local company declined to. I think I pissed the guy off because I had a work telecon going on my phone while I was speaking to him (I can telework up to 10 hours a week without permission). If he's that sensitive, screw him anyway.
Locals have recommended TRANE and York. I have a smaller local company coming out Monday who deal in both those as well as Tempstar. Both Sears and Home Depot were going to install Carrier (though Sears slaps a Kenmore label on it).
I was going to do just three bids, but after reading what Clock wrote I am going to get at least a couple more.
Everyone says my house is 3 tons/36K BTU, so I guess that's right.