Originally Posted by 108Stitches
So, can I put the compustion return 12" from the floor, then put the return 12" from the ceiling?
Just to keep the terminology straight, there is no such thing as a "combustion return", only ""combustion air intakes".
A "return" as generally used in HVAC work refers to a point of entry into the return air ductwork - heated air flowing away from the furnace moves via "supply" ductwork and is returned to the furnace through "returns" via return ductwork.
One of the major objectives of the code requirements relating to forced air heating systems is to supply enough combustion air to the burners so that no exhaust fumes are pulled back into the return air ductwork and circulated inside the structure.