I live in a 2 level condo with forced air heating. The first level is behind the garage with a 2 story ceiling and a large ceiling fan installed. The second level is above the garage and overlooks the first level.

There is a single cold air return on the second floor, directly over the furnace, which is in the garage. When the heat is on, the second level heats up fine, but the first level barely heats up even with the ceiling fan on trying to push warm air downwards.

One issue is probably the 2 story ceiling above the lower level, but would it help to install a second cold air return on the floor of the first level? My thought is that this is the coldest air in the condo and it's never circulating through the heating system and reaching the furnace.

Also what's confusing me, when I asked my girlfriend's brother, an HVAC guy that deals with commercial buildings, he said it wouldn't help. He also said the intakes should be as high as possible for the best efficiency.

Maybe I wasn't using the right terminology? I asked about air-intakes.. . Is an "air-intake" the same thing as a "cold-air-return"? I called it an air-intake when talking to him, so perhaps he thought I meant an outside air intake? Just thinking outloud while typing.. .

Thanks!!

Heat rises. Your girlfriend's brother is absolutely correct about the air return for A/C. There are even systems that have both top and floor vents that you open and close with the season. Shouldn't be much of a job to chop a hole in the wall between the downstairs and furnace and run a duct out to the furnace. Trickiest thing is making sure the wall cavity you choose doesn't have any wires or pipes in it. Poke around Lowe's. They should have 3'' x 14'' metal ducts meant for running up through wall cavities. There are also ''boots'' mean to go up through the floor and connect to round ducts.

When I want to look around without anybody bothering me, I always go to Lowe's.

Thanks for the response labman! I did mention that this was just heating to my girlfriend's brother. Don't even have a/c. That's what confused me.

The condo is pretty new and overly wired. Internet port, outlets, cable jack & switches on that wall. I'll see what I can find out, but it may be something that I get a pro to do.

Also, if I put in a new return, should I also reduce the size of the current 2nd floor return? That seems to make sense to me. Or possibly just block off part of the grate to reduce flow.

You'll want more suction on the first floor because naturally, the second floor will warm up with convection.