do hvac returns need to be same length
The final length of duct may need to be cut to length. Between the return air drop and the AHU, is the location for installation of the filtration system. Most upgraded filters or air cleaners require 7 to 10 Width for the cabinet. 1 wide filters are often cut into the bottom section of the return air ducting.n hvac contractor is going to cost you approximately $50 per hour. You can save that money by taking on the ductwork installation yourself. Your savings could be as upwards of $2,500 for the typical rambler style home.