Ducts are pathways used in heating, ventilation, and air conditioning (HVAC) systems to provide and remove air. These air flows include supply air, return air, and exhaust air, as well as ventilation air. When designed correctly, ducts can help save money by increasing efficiency, balancing air distribution, and providing adequate air flow rates. It is essential to note that a leaking duct system does not balance air distribution and can cause the system to consume too much heating or cooling in certain areas of the house.
This can lead to unnecessary expenses for the homeowner. To prevent this, duct design involves planning (designing), sizing, optimizing, and detailing. Ducts must be one of the first elements to be considered when designing a new building due to their importance to the general utility of the building and the need to integrate complex duct routes with other elements of the general design. This can be especially difficult when structural elements pass through service spaces in the building, such as lower beams, or when ducts have to cross other elements of the building.
Additionally, ducts must be installed to take full advantage of natural air movement. For example, for air conditioning to work properly, return air systems (the large ducts that carry air back to the central unit) must be installed high on the wall of each upper floor to capture the hottest air and return it for cooling. Efficient heating involves installing a return at a low point on the first floor to capture cold air and return it for heating. If the air entering the room cannot circulate to the return duct, it gets stuck in the area surrounding the supply duct. Air velocities in ducts that are too large will not be effective in distributing air around rooms.
The ducts must be able to run between the uprights of the wall and then become a joist compartment (the space between two beams).The air conditioner that circulates through the ducts does not lose heat energy through cold outside air (nor when hot air dilutes the cold air inside the ducts in summer). This helps ensure that energy is not wasted and that homeowners can save money on their energy bills.
