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Form an insulation dam of heat-resistant insulation with at least 3 inches of clearance around a flue pipe in the attic after air sealing around the pipe with sheet metal and fire-rated caulk or canned foam

Form an insulation dam of heat-resistant insulation with at least 3 inches of clearance around a flue pipe in the attic after air sealing around the pipe with sheet metal and fire-rated caulk or canned foam

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If an intermittent ventilation duct is connected to an air handler, the damper should be shut and the intake vent should not be covered when performing a duct leakage test; if the ventilation will be continuous, the intake should be covered and sealed.

If an intermittent ventilation duct is connected to an air handler, the damper should be shut and the intake vent should not be covered when performing a duct leakage test; if the ventilation will be continuous, the intake should be covered and sealed.

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Wrong - The IRC prohibits the use of flex duct for kitchen exhaust and only permits PVC duct for downdraft systems that meet specific exceptions; also, gaps at the ceiling have not been air sealed.

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Right- This flue pipe has been air sealed with sheet metal and fire-rated caulk and an insulation dam has been constructed to keep insulation from touching the hot flue pipe

Right- This flue pipe has been air sealed with sheet metal and fire-rated caulk and an insulation dam has been constructed to keep insulation from touching the hot flue pipe

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A floor cavity between the first and second floor can provide a conditioned space for HVAC ducts if the rim joists are insulated and air sealed, if sufficient space is available, and if open-web floor joists are used

A floor cavity between the first and second floor can provide a conditioned space for HVAC ducts if the rim joists are insulated and air sealed, if sufficient space is available, and if open-web floor joists are used

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This rigid duct connection was repaired using self-piercing/self-drilling sheet metal screws to mechanically secure the connection; then it was air sealed using UL-181 fiber-reinforced duct sealant mastic paste

This rigid duct connection was repaired using self-piercing/self-drilling sheet metal screws to mechanically secure the connection; then it was air sealed using UL-181 fiber-reinforced duct sealant mastic paste

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Sealed Attics?

Reference

Article describing how insulating and air sealing unfinished attic spaces can lead to reduced energy bills in some homes.

Wrong - Hole in duct is not sealed and duct joint to subfloor is not sealed.

Wrong - Hole in duct is not sealed and duct joint to subfloor is not sealed.

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Sealed and Insulated Flex Ducts

Video

Video describing how to seal and insulate flex ducts.

Connection in place but not sealed

Connection in place but not sealed

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Mechanically fastened and sealed

Mechanically fastened and sealed

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Sealing Duct Boots to Floor or Drywall

Guide

Guide describing how to air seal around duct shafts and flues installed through ceilings, walls, and flooring in new and existing homes.

Boot to floor connection not sealed

Boot to floor connection not sealed

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Boot to floor connection sealed

Boot to floor connection sealed

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Boot to drywall connection not sealed

Boot to drywall connection not sealed

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Boot to drywall connection sealed

Boot to drywall connection sealed

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Sealed and Insulated Metal Ducts

Guide

Guide describing how to air seal and insulate metal ducts.

Sealed and Insulated Flex Ducts

Guide

Guide describing how to air seal and insulate flex ducts.

Run-out duct is sealed with mastic

Run-out duct is sealed with mastic

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Insulation does not cover boot and is not sealed

Insulation does not cover boot and is not sealed

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Insulation does not cover boot and is not sealed

Insulation does not cover boot and is not sealed

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Manually seal around the supply plenum

Manually seal around the supply plenum

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Manually seal seams in the return plenum

Manually seal seams in the return plenum

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Manually seal around the return plenum

Manually seal around the return plenum

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Wrong - Duct-duct joint is not sealed.

Wrong - Duct-duct joint is not sealed.

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Wrong - Hole in duct needs to be sealed.

Wrong - Hole in duct needs to be sealed.

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Wrong - Seams in metal ducting are not sealed.

Wrong - Seams in metal ducting are not sealed.

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Wrong - Seam in duct boot is not sealed.

Wrong - Seam in duct boot is not sealed.

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The seams in this HVAC duct are sealed with mastic.

The seams in this HVAC duct are sealed with mastic.

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Sealed and Insulated Fiber Board Ducts

Guide

Guide describing how to air seal and insulate fiber board ducts.

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