What is plenum height?
Furthermore, what is considered a plenum space?
A plenum space is a part of a building that can facilitate air circulation for heating and air conditioning systems, by providing pathways for either heated/conditioned or return airflows, usually at greater than atmospheric pressure.
Beside above, how do I know if I have a plenum ceiling? If the space above the drop ceiling is used for environmental air transfer, meaning the air above the drop is apart of the air return, then it is a plenum area and plenum rated cables shall be installed.
Correspondingly, what is the purpose of a plenum?
A plenum chamber is a pressurised housing containing a fluid (typically air) at positive pressure. One function of the plenum is to equalise pressure for more even distribution, because of irregular supply or demand.
Do I need a return plenum?
Return air plenum is not required. Bottom return air is alot better than pulling from one side of the furnace, the blower motor and CFM is more efficient. Duct work is sized by the tonage of the A/C system and number of heat runs in the house.