Tri-Level HVAC

May 25, 2010 9:09 AM

My part of the house is never comfortable! Help us with our tri-level home heating/cooling issues.

I share a tri-level house with my sister and her husband for half the year. I live in the downstairs area which has its own entrance. There's one thermostat -- in the middle section.

When I get here in April it is still freezing. I dress warmly and am not comfortable. The heat doesn't reach me (obviously since heat rises). In summer, they turn on the A/C and the cold DOES reach me -- but often it's colder for me during summer than it is when it's actually cold out! On the flip-side it's not comfortable for them in summer because the cold isn't reaching their part of the house. They're fine in winter.

In my ceiling there are these circular vents. I rarely feel heat coming from them when the heat is on. I definitely feel cool air from it when the A/C is on.

Has anyone tried blocking their vents in summer to prevent the cold air from coming down?

In winter has anyone tried vents with fans in them that suck the warm air out?

Any other suggestions not involving space heaters?

posted by thorny to Home & Garden (5 answers total)

I had this problem with a basement apartment I lived in for years. Blocking the vents definitely helps. Hardware stores have magnetic pieces that can be placed over the vents, which does better than just shutting them. The problem I had with doing that was condensation building up in the ducts and then dripping out. A good humidifier on the unit will stop that, but you need to watch for it. If the house is newer, it might be possible for someone with experience to redirect the airflow too.

Getting heat downstairs is harder, but they have fans that fit over the vents, and they may help. Also if the furnace is in the basement, leave the door to that room open, and hope the thing is inefficient.

These aren't going to make it great, but they might help a little bit, and if you can get it to work better it should lower the cost for the people upstairs too (in case you need to encourge them to do something.)
posted by Some1 at 9:36 AM on May 25, 2010

You could also try getting them to close their vents in upper section during the winter, so that the heat in their section comes from the bottom and middle floors.
posted by molecicco at 10:04 AM on May 25, 2010

I have a similar problem in my house, I've had some success with using magnetic sheet material (augmented with other magnets because the stuff I got couldn't support it's own weight against the airflow) on my ceiling vents to block cold air downstairs. Additionally, I got a couple of vornado fans, and positioned them to move the cool air up the stairs which helps a lot.

Heat isn't as much of a problem, as the room in question has a large LCD TV that acts as a very effective space heater, but the cold thing is generally fixed by blocking vents and clever fan placement.
posted by quin at 1:29 PM on May 25, 2010

If you have a heat pump, you can leave the fan on all the time so it circulates the air and evens out the temperature. It will still be colder downstairs than upstairs but the difference will be less. Also close the vents most of the way in the summer downstairs and open them all the way in the winter so the heat can get in.
posted by stray thoughts at 3:09 PM on May 25, 2010

Instead of blocking off the feed vents, try blocking off the return vents. I would guess that opening the return in the basement and blocking off the rest might be a place to start.

(Because blocking the feed vents can create a high pressure in the air handler and everything will operate less efficiently. Blocking a return (in my head, at least) allows it to work better.)

Or, look for levers in the vents that feed the various parts of the house. Someone may have "adjusted" them improperly and the unit is already working inefficiently. If they are installed right, full open is parallel to the vent, full closed is perpendicular.
posted by gjc at 4:45 PM on May 25, 2010