Exterior ductwork carries heated and cooled air from the outdoor HVAC system to the interior of a building or home. Manufacturers design ductwork so the sections fit tightly together and are sealed with mastic materials to enhance the efficiency of the thin-metal ductwork. However, the ductwork’s design must also include exterior HVAC duct insulation wrap, which significantly contributes toward efficient air delivery, conserves energy, and improves indoor environmental quality. Poorly insulated ducts can lead to 30 percent duct leakage.
Exterior ductwork insulation systems also require waterproofing products to protect the insulation from damaging water, and preserve its efficiency and integrity and reduce energy costs. Additionally, waterproofing serves as a vapor retarder, to stop moisture migration to the duct’s service, which can lead to condensation, mold, and corrosion.
Fortunately, Polyguard’s Alumaguard® Family of Cladding Products offers self-adhering peel and stick flexible, zero-perm, weatherproof claddings to waterproof exterior ductwork insulation. Polyguard offers both self-healing rubberized bitumen and acrylic adhesion systems for all-weather installations. Additionally, our products meet ASTM flame and smoke requirements, allowing for interior applications.
Alumaguard products can be applied to faced insulation products. It should not be applied to unfaced fiberglass or any unfaced product.
The Benefits of Exterior HVAC Duct Insulation Wrap
For over 50 years, fiberglass exterior HVAC duct insulation has provided four significant benefits to home and building owners.
- Exterior duct insulation helps ensure that cooled and heated air will transmit from the HVAC to interior spaces at comfort levels meeting the occupants’ needs. Increased comfort enhances the occupants’ sense of well-being and productivity.
- Exterior duct insulation lessens HVAC system operating costs by controlling heat gain or loss through air duct walls, and helping systems run more efficiently.
- Exterior duct insulation absorbs the noise generated by the HVAC equipment and air movement through the ducts.
- Exterior duct insulation prevents condensation on or in the ducts if installed according to the R-value recommendation, lessening the change of moisture damage and structurally damaging and unhealthy mold.
Fiberglass Exterior HVAC Duct Insulation Wrap
Fiberglass duct wrap applies to the outside of the sheet metal duct, and provides blanket-type thermal insulation composed of glass fibers bonded together with a thermosetting resin. You can apply duct wrap to round and rectangular ducts. Typically it includes a foil scrim kraft (FSK) or vinyl vapor-retardant facing.
In addition, for ducts not requiring a vapor-retardant facing, you can purchase unfaced duct wrap insulation. Finally, for large metal ductwork, you can apply rigid board insulation with reinforced FSK or all-service jacket facings (ASJ). Some manufacturers offer more user-friendly fiberglass duct wrap, that causes less irritation to the installer.
Installation of Duct Insulation Wrap
- Before installing duct insulation wrap, clean, dry, and seal the sheet metal ducts.
- Cut the insulation wrap to “stretch out” dimensions, including the duct perimeter, plus extra to form an overlapping stapling and taping flap.
- Wrap the insulation around the duct’s perimeter, with the facing out. Tightly butt the adjacent sections with the overlapping flap.
- Staple the seams.
- Apply a Polyguard Alumaguard® self-adhering peel and stick flexible, zero-perm, weatherproof claddings over the duct insulation wrap. Polyguard offers both self-healing rubberized bitumen and acrylic adhesion systems for all-weather installations. All of our proven Alumaguard® products, including Alumaguard® All-Weather, Alumaguard®, and Alumaguard® Lite, carry a 10-year warranty.
Alumaguard® All Weather
Covering exterior HVAC duct insulation wrap with Alumaguard® All-Weather will protect your ductwork from moisture, air, and vapor intrusion. Alumaguard® All-Weather combines rubberized asphalt self-healing features with easy application and the cold-weather performance of acrylic adhesive-based products.
Polyguard’s Alumaguard® All-Weather weather-proofing cladding provides the only flexible insulation cladding offered by today’s market.
Advantages and Features of Alumaguard® All-Weather Flexible Weather-Proofing Jacket
- It uses the same outer layer and rubberized asphalt compound as the first Alumaguard membrane, a product successfully used for over 12 years
- The self-healing quality of the rubberized bituminous membrane seals small pictures and cuts in the Alumaguard®
- Provides excellent waterproofing with True Zero Perm Performance
- Aluminum produces UV stability
- Acrylic adhesive permits installation down to 10ºF
- Requires no activator or pinning
- Offers superior emissivity
- Eco-friendly Alumaguard® All-Weather Cool Wrap offers a “green” energy-saving flexible cladding
- Fast and easy to apply permits for year-round installation
- Sustainable, Cool Wrap™ technologies include a matte white finish
- Eligible for LEED credits
- ENERGY STAR rating
- Surpasses California Title 24 (reflectivity and emissivity)
Companion Products:
- Alumaguard® Lite installed on the underside of the duct removes the need for pinning.
Alumaguard® Air Release Valves, placed on the duct’s bottom, provide a one-way air pressure release related to stress under the bottom of ducts. - Alumaguard® – The Original Self-Healing Membrane
Applying foil-faced, flexible, zero perm, and self-healing Alumaguard® to exterior ductwork provides ideal weather, vapor, and UV protection, with excellent sound attenuation and emissivity properties.
Composite Alumaguard® offers a fast and easy peel-and-stick installation without special tools. However, the rooftop’s design must provide an adequate slope (watershed) to stop ponding water when installing Alumaguard® to rooftop ductwork.
Alumaguard® Cool Wrap™
Alumaguard® Cool Wrap™ offers an energy-saving, green, flexible cladding available in configurations for all Alumaguard® family products. Cool Wrap™ technologies include a matte white finish, meeting emissivity and solar reflectance requirements of Cool Roof Rating Council (CRRC) and California Title 24, and qualifying for LEED credits.
Alumaguard® Lite
You can use lightweight, durable, puncture-resistant UV-resistant, zero-perm Alumaguard® Lite weather barrier membrane for exterior insulated ductwork that is not susceptible to physical abuse but requires a zero-perm vapor barrier.
Alumaguard® Lite Cool Wrap™
Sustainable Alumaguard® Lite Cool Wrap™ has a matte white, high emissivity/reflectivity coated membrane. It qualifies for LEED credits and meets the solar reflectance and emissivity requirements of Cool Roof Rating Council (CRRC) and California Title 24. In addition, for exterior use, Alumaguard® Lite Cool Wrap™ acrylic adhesive provides an eco-friendly zero perm vapor and weather barrier.
Exterior HVAC Duct Insulation Wrap
Placing the HVAC on the outside of a building frees up valuable interior space and lowers building costs; however, the ductwork design must include exterior HVAC duct insulation wrap to ensure efficient air delivery, conserve energy, and enhance indoor environmental quality.
In addition, exterior ductwork insulation systems require waterproofing products, like Polyguard’s Alumaguard® Family of Cladding Products. Waterproofing the insulation will preserve its efficiency and integrity, lessen energy costs, and stop moisture migration to the duct’s service, which leads to condensation, mold, and corrosion.
For more on exterior HVAC duct insulation wrap systems, contact our experts at Polyguard today.