Are you certain that the comfort issues on the 2nd floor are due to the HVAC and not a result of poor air sealing and lack of insulation? I would recommend that you start with an Energy Efficiency Audit by a qualified home energy rater. Using a blower door, IR camera and other diagnostic tools, they can identify the best areas to address to get the most bang for your buck.
I am looking at estimates to replace my dead furnace for my 2nd floor in Chicagoland. I have a 2-zone system with 2 furnaces and 2 ACs (1st/2nd floors). I would like to replace my AC also along with the furnace. The current ones are 80% 60K BTU furnace and 2.5 ton single stage AC from 24 years ago. I always felt that the furnace/AC did not do a good even job for all upstairs rooms(too hot in Summer/too cold in Winter in some rooms even when thermostat showed stable temps). I guess this could have been due to the age of the systems themselves as well as due to the non-efficiency.
You also might consider switching to a combined Heat Pump unit instead of a hybrid AC/Furnace as there are tax credits available under the Inflation Reduction Act as well as significant energy savings.
https://homes.rewiringamerica.org/calculator
Statistics: Posted by id0ntkn0wjack — Wed May 01, 2024 8:00 am — Replies 23 — Views 1860