I have received 3 quotes from different contractors. I do not believe any of the 3 did a Manuel J test or similar. They basically looked around the house and current furnace and made quick judgement call.
1) Amana 2 stage / 107k high-75k low
2) Lennox 2 stage/ 105k high - ? low
3) Carrier 2 stage/ 78k high - 50k low (???)
Bryant 105k BTU Output
Cycles 8 minutes ON; 9 minutes off in 35F degree weather (current)
-Located in Lower Michigan
-Ranch with walkout basement. I consider the "basement" above ground level because only one side (front) is not exposed to the outside - side of hill
-1900 sq ft first level, 1800 sq ft lower (3700 total finished)
-3 of the four sides of lower level (basement) are exposed with single pane windows in two large bedrooms and double pane across entire back. Main level is same layout but windows across front (all single pane). Windows everywhere.
-Built in 1950's - all brick - Below average insulation
What direction should I go? Which BTU rating seems more accurate?
Thanks for your help!