We are remodeling the lowest living level of our 4 level split. The basement is the lowest level. We live in Northeastern Ohio. The level we are remodeling in built on a slab and has the existing HVAC supply lines run through the slab. The supply lines are in very poor condition as very little air comes out of them. As a result, I plan to move the supply lines to the ceiling as I really do not want to go through all of the time and expense of busting up the slab and replacing the supply lines. There is an existing supply trunk that runs through the ceiling of the lower level, which supplies service to the upstairs. I plan to use this supply trunk for the ceiling branches.
My question is what is the best placement for the ceiling vents? Should they be located by the interior wall or the exterior wall? If interior wall, should they come from the ceiling or at the top of the all. If the exterior wall, how far from the wall should they be?
I have included a picture of the layout of the lower level. The supply and return lines are located in the ceiling.
Generally, outlets are placed near windows, as that's usually the coldest part of the room. The best place is in the floor, as heat rises. Second best is in the wall. Worst place is in the ceiling. If you install ceiling outlets, consider adding a ceiling fan to circulate the air. Or keep the undersized floor vents and use both sets simultaneously.
Returns are usually placed on the opposite side of the room from the outlets to force the warm air to travel as far as possible.
The vents in our previous house (1980s construction) were about 12" from the exterior wall. In our current house (1970s construction) they're like 3" from the wall. Not sure what the ideal distance is, though. 12" looks better to me.