1. Existing insulation

• Existing insulation outside of the thermal boundary must be a minimum of R-8 and have consistent coverage of all ducts.

• Any ductwork exposed to the exterior must have a minimum insulation of R-12.

• Insulated flex duct is acceptable when in good condition.

• Damaged or wet insulation shall be removed and disposed of.

• NOTE: If any of the above conditions are identified and not on the Work Order or Energy Audit contact Supervisor and discuss issue prior to proceeding.

2. New insulation type

• Select insulation with a flame spread and smoke development index of 25/50 when tested in accordance with ASTM E84 or UL 723.

• Select insulation that includes an exterior vapor retarder layer.

• Follow the manufacturer's specifications to determine the correct placement of the reflective layer or vapor barrier of insulation.

3. Air seal duct

• See the Air Seal Duct section of this field guide.

• Install all duct air sealing measures listed in the work orders before installing insulation.

• If duct sealing is not listed on work order, discuss installation with auditor before installing insulation.

4. Cut & fit insulation

• Wrap duct with duct wrap or fiberglass blanket. Duct insulation should be a minimum of R-value as noted in Step 1.

• Insulation should have full coverage and be consistently contacting duct with minimal to no sagging.

• Vapor barrier will be facing outwards, not towards the interior of wrapping.

5. Secure insulation

• Insulation shall be durably fastened using mechanical fasteners such as stick pins, screws and washers, plumber straps, or wire.

• Avoid compressing the insulation as much as possible.

6. Tape seams

• All seams of insulation must be taped with UL 181 approved tape.

• Tape in a way that prevents gapping of insulation and allows for continuous insulation.

7. Document insulation R-value

• A dated insulation certificate signed by the installer will be posted on a wall in the space where the furnace is located, a utility room or an approved location inside the building.