This is for the top floor of a 3 floor home. Here is my thinking. Experts in this area, please chime in. To help remove more heat in the top floor, I am tempted to ask teh contractor to install the grill close to the ceiling. Aesthetically, it may not be as pleasing but wouldn't this help in drawing away some of the heat in the summer time?
My furnace has a 2 stage motor but the original developer only hooked it up to run on 1 stage. I am getting central A/C put in and their installer thinks he can re-setup the wires so that it can utilize the 2 stage blower. SO... on the hot days, the cold air return will, in theory, pull out more heat from teh top floor (as it is closer to the ceiling). In the cold days, it will still pull away more heat but I am thinking this is ok since the heat will be on anyways. By the way, thermostat is on middle floor. On the not so hot days, I am thinking I can run the blower to circulate air without using the A/C or furnace heat. Our furnace actually pulls air from cold air returns inside the home as well as a duct that draws air from the outside of the house.
Any thoughts, advanatges or disadvantages on whether we should install the cold air return near the ceiling or ground (on the 3rd floor)?