Put your learning caps on, it’s time for a quick lesson in HVAC! Today’s topic, Plenums. What in the world is a plenum, you ask? For starters, remember that there are typically two types of plenums in your central air conditioning system’s ductwork, the supply plenum and return plenum. Let’s take a look at how each of these components plays an important role in the air distribution throughout your home.

Image Courtesy of Building America Solution Center
Supply Plenum
The supply plenum is a box that is connected to your HVAC system’s supply outlet. Your AC system’s blower sends cool or warm air into the supply plenum, which is then distributed throughout your home via your ductwork.

Image Courtesy of Building America Solution Center
Return Plenum
The return plenum is a box that connects the return ducts in your ductwork back to your HVAC system. You will oftentimes find air filters in the return plenum, because the air that’s currently in your room is pulled in through this section of your system. The air is then sent back into your HVAC system through a return inlet to be put through another cycle of cooling or heating.
Importance of Proper Plenum Installation
We can’t stress enough how important it is to get a quality installation job. In any case, it is well worth your penny for peace of mind. Especially with ductwork, we recommend getting your installation from a seasoned expert. Your supply and return plenums must be properly fitted in order to effectively distribute air throughout your home. Also, proper fitting will help to reduce risks of air leaks and other potential problems within your system. Check out the list below to see a few of the issues that could arise from improper plenum installation.
Potential Problems
- Improper Air Distribution
- Air flow issues
- Elevated humidity
- Poor indoor air quality
- Airflow leaks
- Increased operational costs
- Shortened equipment life
If you have any ductwork needs, whether they involve your supply plenum, return plenum, or other aspects, look for a reputable company for help. At A#1 Air, we put our focus on quality and satisfaction for every step of any installation we do. Contact us today.