I own a three story townhouse with forced air. The summer wasn't too bad with the AC flowing but this winter is horrible. Both bedrooms are on the top floor. Mine is perfect, the other is 20 degrees colder. There is air blowing through the vent, but very little and not nearly enough to ehat the room. I have no idea what the problem could be. The vent IS open and the windows ARE closed. I'd appreciate any suggestions.
The duct going to the cold room could be blocked by something that fell in the vent. Try pulling up the vent (assuming it's just dropped in) and fish around by hand or the vacuum hose. You could also try closing at least partially vents in the other parts of the house to force more air through the vent.
Just a guess: If there is that little flow, it may be that someone installed valves in the ducts to control the flow better than the vents do. You said it was ok in summer; it may be that they made a setup which requires switching over with the seasons. Look at the ducts coming off the furnace and see if you can identify the ones that go to the bedrooms; look for something sticking out the side of the duct that will turn - like a valve handle. If you find it, see if you can turn it back and forth 90 degrees; you'll probably hear the baffle scraping against the inside of the duct. There may be one for each bedroom - you might want to reduce flow to the warm room and increase it to the cold one.
Air balancing is what is needed. Look for a HVAC contractor that does air balancing and has the tools to do the job. It all starts with a room by room load calculation, then the amount of air needed for each room will be known. Most remedial work will require dampers installed and adjusted, some jobs may need new duct work. Hire a professional to get this done
04:03PM | 03/12/04
As mentioned above, find a contractor who specializes in Tesing, adjusting and balancing. Here is a good place to start for qualified, experienced professionals: