I have 14x70 mobile home with 3ton a/c. but the main duct trunk is missing.
what size main duct trunk I need. thanks
info
Where did it go?? You will need to measure the distance from below the floor joists to the top of the framing cross members. Then have ducting made up to fit this space. Last job I did we had 7" to work with. We went with 6" by 24" duct then reduced down to 6" by 18" as we moved farther away from the furnace's location in the duct. Do you have duct drops or perimeter registers?