First floor, I have two tons and 4 returns.
The dining room has my thermostat.
Dining room has one supply and one return.
Supply is on the furthest wall. Return is on the wall between supply wall and thermostat wall.
My feeling is that the return is sucking out the cold supply air before it can reach the height of the thermostat. Both the return and supply are on bottom of wall, same height.
Problem. I need the Stat to cycle more. Air just runs now, because the cold air is being sucked out.
I am thinking about getting one of those vent magnets that cover the registers. Placing it over the dining room return. Reducing the total returns to 3 on a two ton unit.
I need the cool air to stay in the dining room, to drop the thermostat, so it cycles.
What about using the plastic air deflectors? Point it up or down?
Thinking about putting a big wooden chest two inches in front of return, just to slow down the suction out of that room.
Putting holes in a magnet vent cover, so that return still works but not at 100%.