It s a 1600 cfm system with 200 cfm of outside air 200 1600 12 5 of outside air.
Is floor level hvac return air required in basement.
If the supply ducts are high or in the ceiling then the return air ducts or grills should be low on.
By putting the cold air return on the floor it will vacuum up the cold air on the floor and draw down the warm air from the ceiling.
Worse than inefficient the approach of taking return air from a basement or crawl space utility area where gas or oil fired heating equipment is located can be dangerous in particular if by the location of the new return air opening draws flue gases from a nearby draft hood or barometric damper or if the heating equipment is.
A friend who used to install furnaces told me to cut a return in the cold air return to the furnace near the floor.
You determine a return grille pressure zone required 340 cfm of return.
All the cold air in the house heads to the basement since cold air is heavier than the warm air.
If the supply ducts are in the floor then the return air should be located up high.
Yes add at least 1 return at or near the floor in the wall.
So turn the cold air return 90 degrees through the wall so that it actually draws the air from the room next to the furnace room or from the hallway of the basement.
My brother suggested using magnetic vent covers to cover my basement air returns.
Then subtract the percent of outside air from each return air grille airflow in the system as calculated above to find the required adjusted return airflow.
His logic was that this would force the system to suck more warm air from the top floor air returns.
We have four warm air outlets in the basement with no cold air returns.
The return air vent openings need to be on the opposite side of the room so the conditioned air is pulled across the room.
In some installations a central return duct and grill is installed in a central location to reduce cost this has become the norm but is only to save costs.
Return ducts deliver air back to the furnace for re heating and if they re not located near the floor you ll get cold pockets of stagnant air.
I have an air conditioner attached to my furnace and it works well but it mostly cools the basement and the main floor while my upstairs floor is still too warm.
Fail to do this and you ll never have a warm basement.
This is why cold air return ducts must also be installed at floor level ideally on the opposite side of each room from the heating ducts.
