Outdoor Insulation – Bubble

Duct Insulation Outdoor R‑4.2


Note: Installation instructions and illustrated drawings are recommendations only, while proper local construction methods are the responsibility of the installer.

Reflectix® Duct Insulation is an alternative to other types of fibrous insulation products. Ease of handling and quick installation make Reflectix® the first choice when selecting insulation for round or rectangular ductwork in HVAC systems. The product provides an R-6.0 when installed with a 0.75” air gap between the duct and the insulation. There is a choice of three spacer configurations that create the required air space.

Product Description

Reflectix® Outdoor Duct Insulation consists of two outer layers of aluminum foil that reflect 97% of radiant heat. The outside layer of foil is made of heavier foil. Each layer of foil is bonded to a tough layer of polyethylene for strength. Two inner layers of insulating bubbles resist conductive heat flow while a center layer of polyethylene gives Reflectix® high reliability and strength.


  • Wrap rectangular or round ductwork in HVAC applications
  • Heating costs can be greatly reduced
  • Eliminate unnecessary heat loss / gain and air leakage
  • Helps to ensure consistent temperatures
  • Non-toxic / non-carcinogenic
  • Fiber-free
  • Lowers heating and cooling costs year-round
  • Reflects 97% radiant heat
  • Costs less to install
  • Lightweight and clean
  • Not affected by moisture or humidity
  • Does not promote nesting of birds, insects or rodents
  • Resists growth of fungi, mold and mildew
  • Does not require protective clothing or respirators to install
  • ISO 9001:2015 certified manufacturing location

Part Numbers and Sizes

  • CDW48050 (48”x 50’)

Technical Data

  • Temperature Range: 250 Operational
  • Nominal Thickness: 5/16 inch (.312)
  • Weight: 1.25 oz./sq. ft.
  • Flame Spread Index (ASTM E 84): Less than 25
  • Smoke Developed Index (ASTM E 84): Less than 50
  • Fire Rating: Class A/Class 1
  • Linear Shrinkage: None
  • Reflectance (IR): 97%
  • Water Vapor Transmission (ASTM E 96): 0.02
  • Puncture Resistance: 60 lb./in.
  • Mold and Mildew: No Growth
  • Emittance: 0.03
  • Tensile Strength: 3.7 N/mm
  • Pliability: No Cracking
  • Hot Surface Performance: Passed

Note: Not for use in direct contact on surface temperatures that are 180 F or greater.

Testing and Certification

  • Thermal Performance ASTM C518
  • Hot Surface Performance ASTM C411
  • Flame Spread and Smoke Density ASTM E84
  • Fungus Resistance Mil-Std 810B Method 508
  • Pliability Test ASTM C1224
  • Water Vapor Transmission ASTM E96
  • Tensile Strength ASTM C751
  • Emittance Testing ASTM C1371
  • State of California
  • State of California Licensed Insulation Manufacturer
  • State of Minnesota: Filed with Minnesota Insulation Standards Program
  • R&D Services Emittance Testing
  • Warnock Hersey Professional Services, LTD: Physical Properties Sheet Width, Length, Pliability, Water Vapor Permanence and Aged Water Vapor Permanence Report # 1/92
  • Warnock Hersey Professional Services, LTD: Water Vapor Transmission Test ASTM-E96 (Dessicant Method) Report # 1/91

Installation Instructions

Note: Installation instructions and illustrated drawings are recommendations only, while proper local construction methods are the responsibility of the installer. Standard Wrap (Circumference)

  • Make sure all metal joints, seams and penetrations are sealed.
  • Verify circumference of the duct.
  • Cut the Reflectix® product to this length plus 1”.
  • Wrap the product around the duct and securely tape the linear and circumference seams (overlapping 1”- 2”) with Butyl Foil Tape (goal is an air-tight, snug seam seal).
  • Note: The heavier “reflective layer” side of the product should face the environmental elements.
  • Do not leave any exposed duct or space where air can enter between the duct and the Reflectix®.

Please Note Regarding Hangers:

Strap Hanger: Wrap Reflectix® with the seam at the hanger. Tape seam tightly around hanger.


Review These Important Safety Guidelines Prior to Installation:

  • ALWAYS check local building codes before installing Reflectix®.
  • ALWAYS check the area you are insulating and make any needed repairs. Any worn wiring should be replaced before you begin installing Reflectix®.
  • ALWAYS make sure work areas are well ventilated and well lighted.
  • ALWAYS use eye protection when operating a staple gun.
  • ALWAYS use caution and common sense when using a staple gun. Be aware of electrical wiring locations. Stapling into a wire can cause severe shock or death. NEVER staple into electrical wiring.
  • ALWAYS be careful when working with large pieces of Reflectix® on windy days.
  • When installing Reflectix® on bright sunny days, it is best to wear sun glasses.
  • Do not work in areas such as attics when temperatures are too hot.
  • Please Note: The intention of these Installation Instructions and 3-D renderings are for the sole purpose of illustrating the correct location and relative position of the Reflectix® products in specific building assemblies. The correct construction methods and techniques are the responsibility of the installer or contractor. The methods outlined are recommendations on location of the Reflectix® products as a guideline. There are no claims on the part of Reflectix, Inc. that these building assemblies are finite standards or meet building code requirements (as they can vary by region).


Pictured: 1. Outdoor Duct Insulation, 2 and 3. Outdoor Duct Insulation Close-up