So I get 4 bids for replacement HVAC system. All mention duct work improvements. No one leaves me any drawings detailing changes/improvements they propose. All specified 3-ton duel fuel HP/gas furnace systems. Only one did thorough Manual J on his laptop (and spent nearly 3 hours in and around the property). One mentioned doing Manual J calc was in and of itself no good without considering the ducts configuration. OK, so I'm trying to decide between 2 companies, one is the highest bidder, the other the lowest (this one I have an annual maint. contract with and get Trane rebates and extra 10% off on new system). They both priced out same equipment, but one is $2000 higher than the other (this one pitched Lennox signature initially and I wanted his Trane pricing also to better compare to his competitor) -- I imagine the $2K diff is mostly due to extra metal ductwork they'll put in to optimize airflow near the coil (I'm sketchy here on specifics).
The low bid was a salesperson through and through (not sure he had tech skills -- he seemed to know what his competitors would pitch), the high bid was a former tech/installer promoted within his company into sales.
So what kind of ductwork improvement details should I receive from these folks? Given both are equal at installations, and both would put in same equipment, is essentially $2K in ductwork-related upgrades something I must have? This is quite tough to determine what is overkill, what is minimally necessary, and what is best bang for the buck without test driving any of the work.
Another bidder pitched a similar duct improvement and was closer to the high bidder's price, but they didn't offer drawings either.
Without any ductwork improvements, the heating and cooling in the house was OK (before the heat exchanger bit the dust). I'm leaning toward the lower bid. Why shouldn't I?