Plenum in HVAC: Everything You Should Know
A duct system provides a secure path for delivering heat and cold air across a home.
HVAC duct systems are often built of sheet metal, but they can also be made of other hard
heatproof components like fibreglass or insulated plastic. The plenum is the core of any
HVAC duct system, irrespective of construction type. The plenum is by far the essential
part of an HVAC system’s ductwork. The reducers and dampers are essential; an HVAC
plenum performs a dual function. We’ll go through what the plenum does and what to
check for when a plenum in your house needs to be changed.
What is Plenum in HVAC?
A plenum box is a duct-connected HVAC component that consists of an encased box. You
can find them near the air handler or furnace in an HVAC system. Between two plenum
boxes, there is an air filter. You’ll have to take the air filter out from between the plenum
boxes to replace it.
Plenum boxes circulate warm or cool air all across the inside of your house. The HVAC
system must then transfer the heat or cold air via the ductwork after producing it. Plenum
boxes collect this air to blow into the ductwork and circulate it throughout the inside of
Types of Plenum in HVAC
This metal box connects to the supply outlet of HVAC systems such as central heating and
air units and furnaces at the start of the ducts. The air that is pumped into the trunk lines
and branches that run throughout a residence is supplied by the supply plenum. When
you turn it on, the air conditioner unit no longer collects outside air. Instead, the
mechanism recycles the air that pumps through to keep the home’s interior cool.
A return plenum is another type of plenum you can find in houses with HVAC systems.
This air distribution box returns air into your system, as the term indicates. The return
plenum is where an air filter is placed.
The used air is drawn back into the ducts and discharged