High Efficiency Ducts
A duct system that is installed for the cooling and heating of a home or living space is a collection of tubes that arrange for the distribution of the cooled or heated air from the equipment arranging the required temperature control, to the areas where it is needed. High efficiency ducts can make a lot of difference to the effectiveness of the temperature control, and can also have an effect on the health of occupants.
High-efficiency ducts can help the user of an HVAC system to save money, ensure improved comfort and also contribute to protecting health. Most duct systems consist of networks of rectangular tubes made out of sheet metal, fiberglass boards or other plastic and wire composite structures. They are often embedded in walls, or located in floors or ceilings. These ducts are used for the supply of the conditioned air as well as to evacuate the used air through return ducts; that may carry the air back for re-circulation or to the atmosphere. Most ducts will lose between 25 and 40 percent of the energy that is used by the conditioning equipment.
These losses can come from conduction when the difference in temperatures between the air in the duct and that surrounding it. Losses can also come from leakages in joints and walls of the ducts which may be a result of poor construction. Improper duct design can also lead to ducts not functioning as efficiently as they should. The sizes of ducts have to be calculated to provide the necessary air at the required volume and speed. The air has to be under pressure so that air from outside does not find its way into a living space.
High-efficiency ducts will have proper insulation, the appropriate size to suit the conditioning equipment, and made of construction that does not allow for any leakage from joints.