Where will the plenum be installed?

Where will the plenum be installed?

• A. On top of the evaporator coil or the air handler
• B. On the exterior of the building
• C. Under the floor
• D. Inside the duct run

Answer: (A)

A plenum is the air distribution chamber that interfaces the blower with the duct system, serving as the transition point where conditioned air enters the ductwork. Placing it on top of the evaporator coil or the air handler puts this transition right at the outlet of the blower, allowing air to flow smoothly into the supply ducts with minimal turns and resistance. This location also keeps the plenum within the conditioned space and easily accessible for sealing and inspection, which helps maintain efficiency and reduce leaks. Mounting it outside the building would waste energy and expose it to weather; placing it under the floor or inside the duct run would disrupt the intended airflow path and complicate the duct design, so those aren’t appropriate locations.

A plenum is the air distribution chamber that interfaces the blower with the duct system, serving as the transition point where conditioned air enters the ductwork. Placing it on top of the evaporator coil or the air handler puts this transition right at the outlet of the blower, allowing air to flow smoothly into the supply ducts with minimal turns and resistance. This location also keeps the plenum within the conditioned space and easily accessible for sealing and inspection, which helps maintain efficiency and reduce leaks. Mounting it outside the building would waste energy and expose it to weather; placing it under the floor or inside the duct run would disrupt the intended airflow path and complicate the duct design, so those aren’t appropriate locations.