I own a small ranch style condo in Michigan. My unit is a lower level unit built on a slab. I have trouble keeping the house comfortable in the winter. My vents are located in the ceiling and i think i have a forced air furnace with humidifier. The overall sqft of the home is around 1400 ft. I have only one cold air return that runs into the furnace that is located at the ceiling on a wall. Above each door there are vents that go through to each room. I guess my question is in order to force some of the warm air down off the ceiling, shouldn't the cold air return be located in the lower portioon of the wall. I'm not an HVAC guy, but that only seems logical. Any help on this would be great.