You've found the famous Dave's Garden website! Join this friendly global community that shares tips and ideas for home and gardens, along with seeds and plants!
Check out the DG homepage for a brief overview of what you'll find in this gardening mega-site.
Login
If you don't have an account yet, visit the registration page to sign up.
im working on a 1200 square foot ranch on a crawl with a downflow furnace . and its a 50 some year old home with big oval like return ducts in attic , and also has blown in paper insulation up there . well much of the return run has been stepped / kneeled / leaned on over the years from people working or storing things up there and its caused alot of openings where the oval ducts connect . and into these opening for years the paper insulation has been falling , and it gets in the system making the house very dusty in winter . and instead of getting into a semi big repair project and mess with the insulation and ducts in attic im wondering if i can just seal off all the return ducts and just leave two runs coming right off furnace in utility room from the return boot on top of furnace through wall into a kitchen and 8 foot away a dining room on other side of wall . these two ducts dont go into attic and are tight sealed so no dust worry . and all the return duct runs in attic with the insulation / dust in them that run to other end of house where bed / bath / living rooms are would be sealed off . would this be allright to do ?
The short answer is no. Sealing those off will effect the comfort levels in those rooms by creating hot or cold spots. Also if the system was designed correctly, closing off those other returns are going to make the remaining returns noisier as they try to allow the same cubic feet per minute of air return to the heat exchanger and fan. It is also possible that without the correct amount of air returning to the exchanger, it will run hot and you may start to see nusiance tripping of the over temperture safety sensor. The fan will be working harder to move less air since it is drawing against a retriction. If the duct work is really flimsy, the extra suction pressure could even collapse one or two the the remaining ducts. If the system has been costing $$$$ because of the leaks. Repairing them will more than pay for the time spent.
