How Reflective Insulation Works

Heat flows from a hot or warm medium to a cold medium in three ways:

  1. By radiation, from a warm surface to a cooler surface through an air space
  2. By conduction through solid or fluid materials
  3. By convection, which involves the physical movement of air

Heat Flow by Radiation, Conduction and Convection

Radiation is the transfer of heat (infra-red radiant energy) from a hot surface to a cold surface across an air space or vacuum. All surfaces including those of a radiator, stove, a ceiling or roof and insulation radiate to different degrees. The radiant heat is invisible and has no temperature, just energy. When this energy strikes another surface, it is absorbed and increases the temperature of that surface. This concept can be understood with the following example: On a bright sunny day, radiant heat from the sun travels through a car’s window, strikes the steering wheel and is absorbed, causing it to become hot.

Conduction is the direct flow of heat through a material resulting from physical contact. A typical example of conduction would be the heat transferred from hot coffee, through the cup, to the hand holding the cup. Another example is when the contents of a kettle boils from heat transferred from the burner to the kettle. Also, a poker becomes hot from contact with hot coals.

Convection is the transfer of heat by air circulation or movement. Typical examples are forced convection: warm air rising from a heat register, free convection: warm air rising from a chimney, and finally, warm air rising from all of the hot surfaces of a radiator, furnace or wood stove.

Reflective Insulation & Radiant Barriers

Reflective insulation and radiant barriers have the ability to control the transfer of radiant heat in a variety of different applications including buildings, RVs and temperature-sensitive packaging.

Unlike mass insulation, reflective insulation is able to keep heat in and reflect heat away. Mass insulation material like fiberglass and foam merely slow down the transfer of heat; they do not reflect heat away, nor do they keep heat in.

Reflective insulation has the ability to control the transfer of radiant heat. In fact, Innovative Energy’s products reflect (block) 95 percent of radiant heat. Our products are ideal for:

  • Buildings & home insulation: Heating and cooling systems simply work more efficiently when reflective insulation is installed in key areas of a building.
  • Temperature-sensitive packaging: Keeps perishable and temperature-sensitive items safe in shipping and transportation; helps maintain food safety and quality for prepared food.
  • Insulation for RVs and fleet vans: Thin, light, reflective insulation and duct systems are ideal for efficiently heating and cooling small spaces.
  • Controlling heat transfer in just about any situation: Innovative Energy specializes in creating customized solutions for all types of applications.

Reflective Insulation Products

Among Innovative Energy’s line of reflective insulation products is AstroShield. Watch video below to learn how this reflective insulation product can block up to 95 percent of radiant heat.


If you have a need to control heat transfer, let Innovative Energy help. Contact us to find out how we can develop a solution to perfectly suit your needs.

Installing radiant barriers, factors that impact effectiveness

Heat shield radiant barrier
R+HEATSHIELD radiant barrier can reduce energy costs of a building.

There are several important things commercial and residential building owners can do to reduce energy costs of a building or structure. When insulating a home or adding commercial insulation, it is critical to be sure to install the recommended amount of insulation. In many parts of the U.S., installing a radiant barrier can add significant resistance to the transfer of radiant heat coming from the sun.

A radiant barrier is usually installed on the underside of the roof, to help reduce the flow of radiant heat— the kind of heat transfer that you can feel, such as when the sun shines on your skin. Keeping radiant heat from entering the living space can significantly reduce the air conditioning load of the building as well as improve the comfort of non-conditioned structures.

Factors that impact radiant barrier effectiveness:

  • Climate: Areas that require a lot of cooling will provide the best return on investment
  • Attic insulation: As a general rule, the more insulation in an attic, the less effective a radiant barrier will be
  • Location of ductwork: Radiant barrier systems generate greater savings when HVAC ductwork is located in the attic
  • Installation of the barrier: Radiant barriers are subject to the same guidelines as all building materials – correct installation is required for maximum performance

Radiant barrier material costs tend to be low – around 19 cents per square foot – but installation can add anywhere from 35 cents to $1 per square foot on top of that. Owners should shop around and compare prices and reviews when selecting a contractor to perform the work. Your contractor should be able to supply you with results from tests conducted according to ASTM International that will verify performance of the radiant barrier you’ve selected.

Types of radiant barriers

  • Sheet radiant barrier, the most common type on the market, consists of a low-e, (emissive), highly reflective metalized film, laminated to one or both sides of a substrate that can be of another reinforced film, bubble film or foam. The product is most often stapled to the underside of a roof or across the rafters. Single-sided products should be installed with the reflective surface facing the interior (inside) of the attic. A floor installation requires a perforated product so as to not trap moisture in insulation underneath it. These barriers should only be installed on the floor as a last resort since dust accumulation over time will reduce their effectiveness
  • Interior radiation-control coating systems (IRCCS) are applied as a liquid to the underside of a roof with either a brush or sprayer and are ideal for oddly shaped roofs or attics. Consumers should expect an energy savings of 1 percent to 7 percent. Some IRCCS coatings are designed for exterior walls. While no standard exists for these products, payback will be affected by trees or other features that block the sun’s rays from the side of a home.
  • Reflective insulation consists of a core material with one or more outside layers of low-e metalized film. The core can consist of bubble films, foam or kraft sheets that entrap air spaces. When these products are installed in open applications like an attic, they are considered radiant barriers. When they are installed within cavities with air spaces on one or both sides of the material, they are considered reflective insulations. Reflective insulation products can be used along with other foam and mass type insulation materials to help achieve higher system R-values.

As with many products, independent claims for performance of radiant barriers can be exaggerated and it is important for customers to investigate claims that seem questionable. For radiant barriers and reflective insulation products, a good information resource is the Reflective Insulation Manufacturers International Association – www.rimainternational.org. You can also learn more by visiting our website at www.insul.net, or fill out our Simple Request Form to request a free quote or samples.