A brief overview of HVAC ductwork basics helps to understand how these vital components keep your home comfortable and efficient in all seasons. A typical residential HVAC system circulates over 1,000 cubic feet per minute of cooled or heated air. For optimum temperature control, ductwork is designed to distribute a balanced volume of conditioned air to all rooms.
Here are some HVAC ductwork basics and how they affect household comfort and efficiency.
Common rigid ductwork is constructed of sheet metal. Some flexible ducts are made of a wire coil covered with plastic.
Most residential ductwork is out of sight. Main ducts are routed the attic or the basement or crawl space. Branch ducts that extend into individual rooms are installed inside wall cavities.
Supply And Return
Your HVAC ductwork is actually configured into two separate systems.
- Supply ducts convey cooled or heated air from the indoor air handler to individual rooms and living spaces throughout the house. Conditioned air moves through the supply ducts under positive pressure generated by the system blower. The supply vent where conditioned air enters each room is usually located on the upper portion of a wall, near the ceiling.
- Return ducts remove air from rooms and convey it back to the air handler to be cooled or heated again. Return ducts operate under slight negative pressure. In houses with return vents in each room, the vent is located at the lower portion of a wall. Some homes have only one central return vent, usually found in a hallway or other central location.
- Leakage. Over the years, ducts may leak conditioned air. Room temperatures become inconsistent and monthly operating costs rise. Duct sealing by a qualified HVAC contractor can restore system performance and efficiency.
- Thermal loss or gain. Ducts installed in zones that become very hot or cold—like the attic or crawl space—should be insulated to protect against excessive heat gain or heat loss due to temperature extremes.
For more information about HVAC ductwork basics that ensure your home’s comfort and efficiency, contact Detmer and Sons.