Our 17 y.o. York 3.5 ton is probably nearing its life span. We are having contractors from York, Goodman, Carrier and Trane come over and give us estimates for a replacement.

Did a search on this site for heat pump comparisons and found nothing. Any recommendations?

One thing came up: Our house is single level, 2200 s.f. and only one air return. 2 contractors wanted to install another air return and 2 said to take the existing 20x25 inch 3M filter out...and leave it open and install a four inch filter in the air handler, in the garage. Any thoughts on this?

We understand that the most important thing is to have a KNOWLEDGEABLE/PROFESSIONAL/FACTORY AUTHORIZED installer do the job. Correct?

Next most important is a FACTORY warranty or extended warranty. Ironclad, no tricky wording.

Any comments or suggestions would be much appreciated.