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Al’s Plumbing, Heating & A/C in Plano, Texas provides maintenance & repairs for all brands of Central A/C, Gas & Electric Furnace, and Heat Pumps.  Additionally we sell and install new HVAC Systems from American Standard (same company as Trane), Ameristar (same company as American Standard) and Coleman HVAC (same company as York HVAC).

Al’s also provides full service plumbing maintenance, repairs and replacements for every plumbing component in your home.  Al’s sells and installs Rheem Professional Series gas & electric water heaters, and tankless water heaters.  Al’s is near your home in Plano, Allen, and Frisco.  We service all homes in southern Collin and Denton Counties with no travel charges.

Call Al’s today to discuss any concerns or problems you have with your HVAC System or Plumbing.  We will arrange an appointment at your convenience and offer 24/7 Emergency Service.

Covering Ductwork With Insulation.  Is It OK To Do It?

HVAC Ductwork is typically visible in your attic (especially flexible ductwork).  Today’s flexible ductwork is covered with a shiny metallic cover — this is its vapor-barrier.  The shiny vapor-barrier will protect the ductwork from sweating as long as it’s exposed to the surrounding air.

The reason ductwork is exposed is because it sweats in the summer (when a/c is on) the surrounding air will dry the sweat.   If ductwork is covered with insulation without an additional vapor barrier, there is not enough air flow inside to dry sweating ductwork.

Exposed ductwork is great for mitigating a potential mold issue, but not great for HVAC System efficiency and performance. For every 10 feet further from the furnace, the a/c temperature at the duct temperature will be 1-2 degrees higher.  Why?  Because there is an additional 10 feet of ductwork in a blazing hot attic.

Watch The Movie!  View this YouTube Video Showing The Steps In Insulating Ductwork.  YouTube — Insulating Attic Ductwork

YOU CAN COVER METAL DUCTWORK WITH BLOWN-IN INSULATION IF YOU TAKE TWO STEPS FIRST

The existing metal ductwork in an older home may or may not have insulation.  Sometimes the insulation is inside the ductwork.  Other times insulation may be on the outside.

Because the moving air is in the ductwork for only a short period of time, it does not need the insulation R-Value the attic floor requires.   Flexible ductwork comes with different insulation R-Values.

Energy Star Recommendations For Ductwork Are Based On Where The Home Is Located and What Type Of Heating System The Home Has.

  • R-4 to R-8 — Warm:  Large Cooling Requirements / low heating requirements.  This includes southeast Texas (Houston area).
  • R-4 to R-8 — Mixed: Moderate Heating & Cooling Requirements.  This includes DFW.
  • R-6 to R-11 — Cold:  Lower Cooling Requirements / High Heating Requirements:  This includes most northern U.S. states.

Click Here To See Energy Star Recommendations For Flexible Duct Insulation R-EnergyStar Flex. Duct Insulation R-Value

If your rigid, metal ductwork has any insulation, it may already have enough.   If it’s uninsulated, you should insulated it to at least R-4 to R-8 for DFW.  The cost and effort to add more insulation is minimal.  Consider adding more insulation as ductwork is farther from the furnace.

If You Want To Cover Metal Ductwork With Blown-In Insulation,T,hese Steps Must Be Followed In This Order:

  1. Cover The Metal Ductwork With Closed-Cell Spray Foam.  The foam provides a vapor-barrier so the ductwork won’t sweat.
  2. Cover The Spray Foam With Fire-Retardant Spray.  Spray-Foam Spreads Fire Very Fast & Creates Massive Amounts Of Toxic Smoke. 
  3. Once 1 & 2 Are Complete, You Can Add Blown-Fiberglass Insulation

Click Below To See How Fast Foam Insulation Spreads Fire  How Much Toxic Smoke Is Generated.  Foam Insulation Fire-Spread & Smoke Fire In FranceS

You Don’t Want To Create A Hazard Like This In Your Attic. 

 

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Al’s Plumbing, Heating & A/C in Plano, Texas provides maintenance & repairs for all brands of Central A/C, Gas & Electric Furnace, and Heat Pumps.  Additionally we sell and install new HVAC Systems from American Standard (same company as Trane), Ameristar (same company as American Standard) and Coleman HVAC (same company as York HVAC).

Al’s also provides full service plumbing maintenance, repairs and replacements for every plumbing component in your home.  Al’s sells and installs Rheem Professional Series gas & electric water heaters, and tankless water heaters.  Al’s is near your home in northern Dallas, Garland & Richardson.  We service all homes in southern Collin and Denton Counties with no travel charges.

Call Al’s today to discuss any concerns or problems you have with your HVAC System or Plumbing.  We will arrange an appointment at your convenience and offer 24/7 Emergency Service.