What is the difference between a plenum and duct?
A plenum is an air distribution box designed for forced-air systems on residential homes and commercial businesses. It is part of the ductwork, but far different than an air duct as these important boxes handle air as it enters the ducts and helps to recirculate it within a system.
What is the purpose of a plenum on a furnace?
Plenum boxes are usually situated on either side of the fan or heat exchanger and have the important function of bringing in, distributing, and removing air. They are the air’s first stop after being heated or cooled and its last stop before going back into your AC, heat pump, or furnace.
What is a plenum duct?
A plenum is an air-distribution box attached directly to the supply outlet of the HVAC equipment that heats or cools the air to make the house comfortable. The ductwork that distributes the heated or cooled air to individual rooms of the house connects to the plenum.
What size should my plenum be?
Single plenums should not exceed 24 ft in length. Double plenums should not exceed 48 ft in total length.
Do I need a plenum?
Most residential buildings don’t have plenum airspaces. Plenum areas are more common in commercial buildings. However, if your house does happen to have a plenum airspace or you need to run cables through an air duct, then plenum-rated cable is required.
In which type of furnace is the plenum located on top?
EVAPORATOR COIL This is the piece of your air conditioning system that most people never see. It’s contained in a metal box called a plenum, and sits on top of your furnace. If you have a horizontal furnace in an attic, the evaporator coil will sit on one end of the furnace instead of on top.
Should I insulate my furnace plenum?
simple answer…all supply plenums and ductwork, fittings, etc. is required to be insulated, and only after sealing all joints/connections with either approved foil tape or mastic material.
Is it OK to reduce duct size?
By restricting the duct size it will cause more resistance and have less air flow because the air will take the path of least resistance. All the other ducts would have a higher flow with the 6″ compared to a 8″ duct because they are all in parallel. Such a reduction will increase noise.
Where is plenum required?
If you have a large wall or ceiling return air grate; remove and see if there the air is channeled through sheet metal ducting. If there is no sheet metal duct; just the open ceiling or wall space, then you are required by law to use Plenum Rated cable.
Is plenum required for residential?
Do I Need Plenum Rated Cable in My Home? While it’s definitely acceptable to use plenum-rated cable in your home to install a signal booster, a WiFi network, or something else, more often than not, it’s not necessary. Most residential buildings don’t have plenum airspaces.