mini duct systems

Old houses simply don’t have room for the conventional ductwork a whole-house, forced-air heating and cooling system

requires. Ductwork consumes headroom in basements and in kitchens (as soffits). Installing the wall ducts often means losing precious storage space in closets, or disturbing original plaster and even finishes like expensive wallpaper. Mini-duct systems —offered by two companies based in the U.S., SpacePak and Unico, and one in Canada, Hi-Velocity—literally work around those problems with small ducts made of flexible tubing.

At about 3" in diameter, the ducts are small enough to be routed between studs in walls and in cavities under floors and above ceilings. The system works by aspiration, quietly pumping warm or cool air at high velocity throughout house. This creates a gentle circulation pattern that produces relatively even heat from floor to ceiling. Rooms typically feel more comfortable, even at lower temperature settings. The compact ductwork has also been found to leak less than conventional forced-air ducts, which means even more energy savings.

Mini-duct systems are usually equipped with the latest in air filtration and humidification ystems. Tests show they’re capable of removing up to 30 percent more humidity than a traditional forced-air system. (The drier the air on a hot summer day, the cooler the house will feel.) The system can add humidity in cold, dry weather for increased comfort. Installation is not without its disruptions, but outlets are smaller than conventional floor grates and can be trimmed to accent or conceal them.