Should I replace duct work & furnace
I bought a one story 1900 square foot house built in '69 last year. Duct work is in the floor, but the air flow is very weak in parts of the house. The heat seems to work ok, but generates a lot of heat around the furnace (seem to be leaks in the ductwork connecting furnace and rest of house). When we try to use air conditioning, air blows, but is not cool. We had several repairman come under our home warranty policy and they say air conditioning is "technically working" even though it doesn't cool the house. We are tired of trying to fix things piecemeal and think we need to just replace part or all of the system. The outside 2 ton air conditioning unit is about 13 years old. The current gas furnace is an entry level Trane, and about 3 years old. A couple of HVAC companies told us they would use the existing duct work, but replace the furnace with a variable unit (Carrier #58CVA070-12, 80% efficient), and that would solve our problem. One company suggested replacing the floor duct work with duct work in the attic (which they said would help air flow), replacing the air conditioner with a 3 ton Carrier (#24ACC624) and the coil (#CNPVP2417) but keep the furnace (which is not variable speed). All of these estimates are in the 6-10k range. What makes the most sense? Replace duct work only, replace furnace only with variable speed, or replace everything?