I am supposed to be getting my new Tempstar HVAC system installed today. I bought my first home (built in 1978) this past September and the old unit was put in 1989. The home inspector said it was in working order but the A/C compressor needed to be replaced. And since the unit was so old, I would need to purchase a new furnace when I replaced the outside unit. I got quotes from three contractors (Amana, Trane, & Tempstar) and decided to go with the Tempstar bid. Three ton, 13 SEER A/C, 90% Furnace with VSF & UV light. 10yr parts & labor warranty on everything. By the way, none of the contractors did any of these calculations that I have been reading about on here. I also asked a few people I know that have recently purchased new units if their contractors did any type of load calcs and they didn't even know what I was talking about. I'm really excited about getting this new unit. I took some pictures of the old unit so you guys can see what shape it was in. I will then post some pics of the new system once it is installed.