I have been reading over posts in here about how older ductwork can affect furnace performance and fan noise.
I live in upstate NY in a 1450 sq. ft. house built in 1928. Currently have a 1980 Williamson oil furnace (100,000 btu), no wall insulation and minimal attic insulation. We are working at getting insulation added and upgrdaing to a gas furnace.
We qualified for a grant through NYSERDA to get 50% paid upto $5000. That being the case, my heating contractor was keen to sell me their best furnace (3 stage, varable speed 96.6% Carrier). I think that is overkill, but liked the reported savings the variable speed motor offers, plus the increased comfort of the 2 stage. So I am now leaning towards a 92% Payne (2 stage & variable)
However, given that the ductwork in my house is older (not sure exactly how old) will this negate the 2 stages? Would I be as well saving some money and getting a good single stage?
Also the new furnace is sized at 60,000 btu, will this be sufficient to heat the house through the old ductwork?