When comparing bids and price quotes for a new AC and heating system, an essential component often gets glossed over: the ductwork. Because of rebates and tax credits, a lot of attention is placed on SEER, EER, energy efficiency ratings and other new equipment features. However, unless the ductwork is professionally sized, configured, and sealed with the newly installed equipment, even the most advanced new HVAC system will not cool or heat your home at optimum efficiency.
Ductwork may be difficult or inconvenient to get to
Another reason ductwork can get less attention than it deserves: it may be difficult to get to. Ducts in two story houses can be encased between the floors. More often, it is in the unconditioned attic where it is blazing hot and surrounded by itchy insulation and desiccated mouse droppings. Of course, in a pier and beam house with vents in the floor, the ductwork can be located in the crawl space under the house with spiders, snakes and other biting/stinging varmints.
Ductwork is a variable
The vast majority of local heating and air conditioning companies strive to deliver quality work and above board cost proposals. However, for the rare contractor that is more focused on winning the signed proposal than delivering quality, the existing ductwork represents one of the least tangible areas. To them, it could represent a variable where advantage or shortcuts might be taken. Any proposal for a new system should address the ductwork. This includes whether ductwork will be definitely replaced, if there are any variables or contingencies (if mold is found when removing old equipment, for example), and specific costs for each scenario.
The whole house approach to HVAC
In summary, central heating and A/C equipment relies on the ductwork to deliver the conditioned air and not waste it. Be sure to take the whole system — the air ducts, the ductwork and the envelope (the places where your house meets and interacts with the outside environment) –into account when you plan and budget improvements to your HVAC system.