The importance of choosing the right HVAC person has been rightly stressed here. Can anyone provide some tips on what to look for? Would a owner-installer firm be better than a larger one that has salesmen who contact you and give you an estimate over the phone? Would a firm that installs more types of equipment be better than one that concentrates on only one or two? Is there a 1-2-3 checklist that you guys can recommend?
Some years ago I went with a replacement Carrier unit for my upstairs, because the design guy impressed me by spending a lot of time walking around measuring everything and apparently doing some calculations. Then he comes up with the brilliant idea of closing off one of the two vents in a bedroom which was about 3/4 the sq. footage of the master bedroom that had 3 (including a small dressing alcove). I trusted his 'expertise' against my wife's foreboding. You can guess what that room turned out to be - hot during the summer and cold as blazes during the winter. I finally got someone to connect the by-passed vent. (BTW, the argument that the designer gave me was that the higher air flow would make up for the loss of a vent.)