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  1. #1
    Join Date
    Jan 2015
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    East Tenn
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    What's the smell like? Mildew? Are the vents clean?

    Seems Every Time these Insulation Con Tractors do Blow Job , Think it's OK to Leave 12" of Insulation up against the Roof Joist - Soffit Openings . .

    Check for Condensation Spots , as Fan just won't do - Unless it's Huge . . Especially Blocked Soffit Vents . .

    Your Duct Run may be getting Condensation Build Up - If You don't have Directly Connected Dehumidifier . .
    Especially with all this High Humidly . . just My 5 Cents


    I Do Care !
    Do You Give a Plug Nickle ?

    Also , For Those Plug & Play - Wh___... that can't Finish Up Job Correctly or Forget 7 different Details - Which the Home Owner takes Care Of for Free ..
    ( Like Plumbing Sealer on Gas Union ) Dope is what I really Mean to Say !

    Yeah , I do What a FREE ESTIMATE !

  2. #2
    Join Date
    Jun 2003
    Location
    Madison, WI/Cape Coral, FL
    Posts
    9,673
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    Quote Originally Posted by QualityAssure View Post
    Seems Every Time these Insulation Con Tractors do Blow Job , Think it's OK to Leave 12" of Insulation up against the Roof Joist - Soffit Openings . .

    Check for Condensation Spots , as Fan just won't do - Unless it's Huge . . Especially Blocked Soffit Vents . .

    Your Duct Run may be getting Condensation Build Up - If You don't have Directly Connected Dehumidifier . .
    Especially with all this High Humidly . . just My 5 Cents


    I Do Care !
    Do You Give a Plug Nickle ?

    Also , For Those Plug & Play - Wh___... that can't Finish Up Job Correctly or Forget 7 different Details - Which the Home Owner takes Care Of for Free ..
    ( Like Plumbing Sealer on Gas Union ) Dope is what I really Mean to Say !

    Yeah , I do What a FREE ESTIMATE !
    Just out of the blue, what a good post!

    A bit more elaboration on the point. We are finding a lot of condensation on the outside of a/c ducts buried in loose fill fiberglass insulation in attics and crawlspaces. Some of it is very difficult to fix.
    Yes, poorly ventilated attics can build up moisture levels, increase the dew point above outdoor levels. Most are more complicated. The main problem is that a/c supply temperature is below the attic air dew point. Well insulated ducts with vapor barriers on the high dew point side are usually ok as long as they do not touch each other. But as they become surrounded by the loose fiberglass insulation, the vapor barrier become cooler than the dew point of the air in the loose fill fiberglass. Like magic, condensation forms. Passing through the fiberglass going to the supply grill could be 18" below the top of the loose insulation. The vapor barrier at the grill connection is more like the cold air temperature than the attic temperature. Condensation may accumulate during long cooling runs to the point of moisture bled through to the drywall side of the ceiling and around the grill.
    We are seeing this problem more and more in the upscale more loose fill homes in the SE US.
    What to do?
    Good attic air change to avoid moisture build up in the attic. A hotter attic keeps the vapor barrier of the duct warm, therefore less condensation on the vapor barrier. Some are spraying closed cell foam around the duct/grill box area to avoid condensation from the damp air in the fiberglass. Fine tuning of the a/c supply air temperature helps.
    The supply air must have the moisture removed to provide <50%RH in the home. This is done by supplying air that passes through a 45^F cooling coil for a 75^F, 50%RH, 55^F dew point condition. Some attempting over-cooling to get the moisture out. Over-cooling makes the problem worse because the duct is colder, more condensation and longer.
    Because moisture remove is impossible during cool damp weather, some are adding a small whole house dehumidifier to the a/c supply duct. This allows raising the inside t-stat to a couple degrees warmer while maintain <50%RH during low/no sensible cooling loads. The dehumidifier warms the ducts while maintain low indoor %RH evenings and rainy days.
    The fan of the dehumidifier is operated 24/7 with 200-300 cfm of bypass house air warming the cold air from the a/c. This raises the duct temperature 5-8^F, reducing condensation problems in the attic and on the grill.
    Spray foaming the attic with closed cell foam at the drywall ceiling also would help.
    Interested in hearing other solutions.
    Hope this helps.
    Regards Teddy Bear
    Bear Rules: Keep our home <50% RH summer, controls mites/mold and very comfortable.
    Provide 60-100 cfm of fresh air when occupied to purge indoor pollutants and keep window dry during cold weather. T-stat setup/setback +8 hrs. saves energy
    Use +Merv 10 air filter. -Don't forget the "Golden Rule"

  3. #3
    Join Date
    Jan 2004
    Location
    PA
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    78,349
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    You should probably go to an insulation forum, and complain about them there.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  4. #4
    Join Date
    Jan 2015
    Location
    East Tenn
    Posts
    194
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    Thread Starter
    Hi Teddy Bear . .
    I Tried Opening up Soffit's Garage Area and Actually Got Condensation , as those were Sealed Right Off 100%
    Damp Fog - Drifted right Up , also here in South ( BUGS , BUGS , BUGS ) I had to Install really Small Screening to Protect & Added Additional Upper Ridge Venting .

    My Latest Venture into this Area ( Attic ) is to Install ( Radiant Heat Barrier ) This seems to be one of the Best Items - to do Attic ..
    You Might get By - Just Laying a Radiant Barrier Over the Cooling Runs - the - System will Not have to work so Hard - Possibly Keeping that Area from Getting Super Cold .

    I Actually Installed Between the Roof Joist - Super PITA - with - Spacer .. 3:am When is Cold Outside get started ..
    Face Mask etc. Couple Pc.s of Plywood to Move around on as Not Finished or any type of Floor - Oh Joy ..
    due to the Fact - Your Over Driving the Cooling Unit to Obtain Temp ..

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