Table of Contents
What is the purpose of having a plenum connecting the ductwork to the air handler?
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.
How do you size a supply plenum?
One is that the supply plenum should be no larger than the blower opening off the top of the air handler, which seems small, at only 16×11″. But most opinion, particularly from the HVAC supplier, is that the plenum should be the same size as the overall A.H. cabinet size, which is 17.5 x 21″.
What is a return air plenum?
What is a return plenum box? The return plenum box receives used air from the return vents and distributes it to your HVAC unit to be heated or cooled again. The used air must pass through a filter before entering the return plenum, ensuring that it’s clean before it reenters your AC, heat pump, or furnace.
Should return air vents be high or low?
For optimal efficiency, it’s ideal to have return registers installed. To ensure efficiency during the cooling season, your home should have high registers. High return registers draw hot air that rises to the ceiling back into the system to repeat the cooling cycle.
Is a plenum necessary?
Forced air HVAC systems tend to be the norm in today’s home construction or renovation. Through a series of ducts and vents, warm or cold air is pushed through from the unit’s blower fan. In order for everything to work properly, the HVAC unit requires a plenum to accomplish the tasks.
Should the plenum be insulated?
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.
How does a plenum chamber work?
A plenum chamber is a pressurised housing containing a fluid (typically air) at positive pressure. One of its functions is to equalise pressure for more even distribution, compensating for irregular supply or demand.
What is a Lockformer used for?
For over 75 years, Lockformer has been the most recognized name in the sheet metal machinery industry — leading the world in the production of HVAC duct and fittings fabrication equipment solutions including insulation cutting equipment, metal cutting systems, rectangular, round, and oval ductwork roll forming.
What is 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 through your ductwork.
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. Keep branch run starting collars 24 in.
How tall should a supply plenum be?
For a gas furnace, the top of the plenum needs to be a minimum of 1″ from the bottom of the floor trusses. If the manufacturer has a requirement, it will be in the IOM that came with the furnace. 20″ tall will be fine.
Does Flex duct reduce airflow?
Friction is the enemy of airflow. Unlike rigid ducts, which are cut to length within a tolerance of 1 inch or less, it’s easy to cut a length of flexible duct that’s several feet longer than is needed to get from point A to point B [2A]. That creates slack in the duct, which reduces airflow for two reasons.
Can you use flex duct return air?
Flex duct can be used for return air, but there are some conditions for its use in this application. Pressure must also be considered, and flex duct can only be used for return air if the air is pumped through it at lower pressures than the regulated maximum air pressure according to the diameter of the duct.
What is the difference between a flexible air duct and a flexible air connector?
The listing label on “flexible duct” is rectangular in shape and states “Listed Air Duct.” The listing label on a flexible air connector is circular in shape and states “Listed Air Connector.” Both are listed to UL 181 requirements. The length of a “flexible air connector” is limited to 14 feet maximum.
How do I join metal ductwork?
Joining metal ductwork in your home is done through attaching metal-to-metal joints called slips and drives, and fastening them with drive cleats and self-drilling, sheet metal, hex-head screws. Residential ducting is a combination of rectangular and round channels with adjustable elbows.
Why do we use plenum in HVAC?
Plenum boxes are used to distribute heated or cooled air throughout your home’s interior. After producing heated or cooled air, the HVAC system must move that air through the ductwork. Plenum boxes take in this air so that it can be pumped into the ductwork and, therefore, distributed throughout your home’s interior.
Where is the 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.
What is a plenum in an HVAC system?
In building construction Plenum is a separate space provided for air circulation for heating, ventilation, and air-conditioning. It is commonly found in the space between the structural ceiling and a drop-down ceiling or under a raised floor.
Do you put a filter in a return vent?
Should you use a filter in your return vent? For most homes, return vents filters are suggested. They typically won’t cause any damage to your HVAC system and are easy to install – there’s no need for an HVAC technician.
Where do you put return air vents?
Place your cold air return vents on the inside walls of buildings at the lowest point. The return vent pulls cold air from the bottom of the room and returns it to the furnace to be reheated and returned as warm air.
