I had a AC guy look at the units and heating on a house I just purchased. The AC units serve a 3500-3800 sq. foot house and are 2000 and 2002 yrs.. The AC guy said that the air handlers are 35 yrs. old and that I am using electric strips for heat. He doesnt know if they work and rec. a whole new system with heat pumps for 12k. He said my bills will go down 40%. The house has large expanses of glass walls. I will get more quotes but wonder if this price sounds high? This includes new air conditioners. He said something about 16 seer.