Hybrid Insulation System

Hy-Fi Radiant Barrier Wall high R-Value

HY-Fi is a cutting edge hybrid insulation product that provides a very cost-effective approach to creating high R-value walls. The HY-Fi hybrid insulation system combines low emittance surfaces and enclosed air spaces. When used in combination with traditional insulation, such as fiberglass batts or spray foam, it creates a superior insulating system at an unmatched price point. HY-Fi is an especially attractive solution in areas with stringent building codes as it provides insulators and builders with a versatile, low cost, and easy to install hybrid system that achieves R-21 in small wall spaces. 

HY-Fi Insulation addresses the dominant form of heat transfer--radiation--with layers of high reflectance and low emittance materials. This configuration creates three reflective air spaces between the interior wall and traditional insulation that adds an additional R-8 to the wall -- which can reduce the amount of sprayfoam or fiberglass batts needed to achieve the desired R-Value.

Supporting Documents


  • Insulation for Wood Framed Buildings
  • Hy-Fi with spray foam insulation
  • Hy-Fi installed on wall high R-value insulation
  • Hy-Fi Radiant Barrier Wall high R-Value

Product Key Specs

Furring/Stud Spacing 16" O.C. 24" O.C.
Width Expanded 17.5" 25.5"
Diameter 12" 10"
Lineal Footage 375' 250'
Coverage 500 sq. ft. 500 sq. ft.
Weight 29 lbs. 27 lbs.
2" x 4" Frame WallHy-Fi™ with 2" R-6.75 Spray Foam R-21
2" x 6" Frame WallHy-Fi™ with 3.5" R-13 Fiberglass R-21

Product Test Data

Test Method Description Results
ASTM E-96 Water Vapor Permeance 0.20
ASTM E-96 Water Vapor Permeance Hi-Perm 5.42 perms
ASTM E-84 Flammability Flame Spread Rating 20
Smoke Development Rating 10
Interior Wall & Ceiling Finish Classification Class A
ASTM D-3310 Corrosivity None
ASTM C-1224-99 (9.2.1 & 9.2.2) Adhesive PerformanceBleeding None
Delamination None
Pliability No signs of cracking or delamination
ASTM C-1338 Mold & Mildew Pass
ASTM C-1371 Foil Emittance 0.034

Builders: Get Free HY-Fi for Your First Project

Yes, for qualifying builders, we'll supply HY-Fi for a 2500 sq ft home!


Compliance and Approvals: 

Meets or exceeds ASTM C1224, the Standard Specification of Reflective Insulation.
Meets 2009 and 2006 International Building, Residential and Energy Codes.
Meets 2010 and 2007 Florida Building, Residential and Energy Conversation Codes.
IAPMO Evaluation Report number 0266, Sections 3 & 4.
Hy-Fi hybrid insulation

What Our Clients Are Saying

I am always walking the builder trade shows, looking for an industry changing product.  I think I found one with Hy-Fi.

St. Charles, Illinois

Project Profiles

Zylstra Harley Davidson
Project Information: Project Location: Ames, IA Insulation Contractor: Walker Spray Foam 21327 Quinlan Ave.Dallas Center... Read More


A reflective insulation below the roof deck results in an interior surface temperature that is greater than the outside temperature (in cold weather). As the inside surface temperature increases, the conditions for condensation become less likely to occur.

Reflective insulation has little effect on heat transfer by conduction through the air between hot and cold surfaces.  Air with an R-per-inch of 5.6 is an excellent insulator when radiation and convection are controlled.  The installation of reflective insulation in an enclosed space reduces thermal radiation to near zero.  When the reflective insulation is installed to subdivide an air-filled region then convection is also reduced.

30 minutes is the best waiting period before installing Hy-Fi.  As the spray foam cures, moisture is released through an exothermic reaction (looks like steam).  It is best to allow this moisture to escape before instaling Hy-Fi.

The "tested" value is for specific dimensions - specifically the air space between the Hy-Fi and foam.  The tested precision is about +/- 10%.  In view of this, the agreement between the calculated and "tested" values are quite good.  Hy-Fi adds R-7.1 to the insulation assembly with a 1.5" air space.

Yes. The ASHRAE Handbook values are a subset of data from the National Bureau of Standards (NBS).

The R-value for a reflective air space depends on the temperature difference across that air space.  The temperature across the air space depends on the r-values in the system since the bounding temperatures are fixed.

Hy-Fi is the hybrid insulation system combining spray foam insulation with VR Plus Shield Reflective Insulation.  This system defends against all forms of heat transfer at a reasonable price.

Reflective insulation is one or more low emittance surfaces installed in an enclosed air space. The more layers within the air space, the better the performance. Reflective insulation in a wall system can be compared to a double or triple pane window with low-e surfaces. Triple pane windows with low e surfaces perform better than a triple pane window without low e surfaces because of the reduction of radiation (low emittance) across the air spaces.  

Air inherently has an R-per-inch value of 5.6, and is an excellent insulator when radiation and convection are controlled. The ASHRAE Handbook has tables with values for various enclosed air spaces (0.5”, 0.75”, 1.5”, 3.5”, etc.) with high emittance surfaces (0.82 for common building materials) and values for air spaces with low emittance surfaces facing the enclosed air space (0.05 for low emittance materials like aluminum).  Simply put, adding a low e material makes the enclosed air space perform better. A multilayer reflective insulation system in a wall cavity improves this system by further reducing radiant heat transfer and adding additional “panes”, a two layer reflective insulation could be compared to a double paned window; a three layer to a triple pane window, and so on..  

The installation of reflective insulation in an enclosed space reduces thermal radiation to near zero. When the reflective insulation is installed to subdivide an air-filled region then heat transfer by convection is also reduced. Fi-Foil has single layer, two layer, three layer and even honey-comb layer reflective insulation products for various building applications, each with different performance levels and attributes for the particular application. These products also work very well with other types of mass insulation as hybrid systems by using the best attributes of each of the technologies (e.g. spray foam is great for air sealing and can have a high R--value per inch of thickness --  fiberglass and cellulose is an inexpensive material to reduce convection in the cavity). In some wall systems, especially wall cavities larger than 1.5”, a combination of reflective insulation with one or more of these mass insulation products, addresses all the modes of heat transfer -- often more cost effectively than one of the technologies used alone.


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