How Does Reflective Insulation Work?

When you’re thinking about insulation options, there are several different methods, and finding the best choice for your application really comes down to understanding how each product works. Whether you’re talking foams, fiberglass, cardboards or shiny bubble wrap, each one works to insulate in a different way. Before we dive into products, lets first address that choosing which insulation is appropriate for you starts by understanding what type of heat transfer you are dealing with.

Okay, I promise not to over-do the science lingo here, but let’s cover how heat transfer works. There are three modes of heat transfer: conduction, convection, and radiation (infra-red). Of the three, radiation is the primary mode; conduction and convection come into play once matter interferes with the radiant heat transfer.

CONDUCTION: Conduction is direct heat flow through matter from actual physical contact. For example, an electric stove uses conduction to transfer heat to a pot resting on the surface, which is also conducted to your fingers when you make contact. The more contact, the greater transfer of heat. This movement of heat is always conducted from the hotter surface to the colder surface, never reverse. Generally, the greater density of an item, the better conductor it is; so inversely, the less dense the mass, the less flow of heat by conduction.

CONVECTION: Convection is the transport of heat within a gas or liquid. Think of a group of people in a tiny room. Their body heat will transfer to the air around them making the room feel hot. These warmed air molecules move in a general upward motion.

How does reflective insulation work?

RADIATION: The last and most prominent mode of heat transfer is radiation. Radiation is the transmission of electromagnetic rays through a space. Like radio waves, waves of radiant heat are invisible, and for this article’s purpose we will be referring to inferred rays only. Mostly everything emits infrared radiation, sending rays from their surface in every direction until they are absorbed or reflected by another surface. These rays have no temperature, only energy. When the rays strike another object, the rays are absorbed and only then do they create heat. The heat then transfers through the object by conduction and then new rays are emitted out of that object.

The amount of radiation emitted is a function of the emissivity (or rate at which radiation is given off) of the source’s surface. So, in plain english, an object (or surface) with low emissivity absorbs little rays, but rather has high reflectivity. Insulation layered with metalized film, like our Astro-sheild, has a low emissivity of 5%. This means it is reflecting approximately 95% of the rays that strike it. This high reflectivity is greatly reducing radiant heat from being transferred into the surface, intern working as effective insulation.

TRY THIS EXPERIMENT: Hold a piece of Astro-sheild reflective insulation close to your face without touching the surfaces. You will begin to feel the warmth of your own infrared rays being reflected back towards your face and being absorbed by your skin surface. While your skin and the insulation are both solid surfaces, the insulation has a low emissivity (5%) and your skin has an emissivity of 99%, so the rays are being absorbed by your skin and heat is conducting throughout the surface.

You can imagine how the same principles would apply as this effective insulation is implemented in a building or packaging application to help keep heat transfer to a minimum, and keep your space in a desired temperature range.

*Do you have a building that you’d like to keep cooler in the summer and warmer in the winter? Call us about using reflective insulation. 800-776-3645 or

*Do you have temperature-sensitive goods you’re worried about shipping? Call or email us about using InsulTote packaging to keep your goods safe during transit. 800-776-3645 or

Put Those InsulTotes to Work- Again!

InsulTote liners can keep your rotisserie chicken hot, or your ice cream cold, all the way home! Whether you ordered an InsulTote liner on your own, or received one in a temperature sensitive package you received, put it to work! You may know that the reflective insulation in InsulTote liners stop heat transfer and work to keep items cold or hot, but you might be missing an opportunity to reuse these handy little helpers. Reusing your shipping pouches and box liners will save you money, save your groceries, and help to save the planet. At Innovative Energy, we are committed to sustainability, and encourage you to take every opportunity to get the most out of your products.

We understand that this can require a tiny bit of effort to get into the new routine of carrying InsulTotes with you, but the benefits are so great that we want to help you get started!

Here are a few easy tips to help you remember to re-use your InsulTote liners and shopping bags (before you’re already in the checkout line).

  1. Color Coordinate- Place your InsulTote liners in your brightest colored shopping bag with your other re-usable bags; using the brightest colored bag to store them will make it easier to spot in the car, and harder to forget! They’ll all be in one easy-to grab-bundle. 
  2. Put them on your list!- Add “InsulTote liners” to the top of your shopping list so their on the brain before you head out the door.
  3. Reward yourself!- If you remember to take your InsulTote liner into the store, pick up your favorite frozen/refrigerated/hot treat! Ice cream bar? Pizza slice? Chocolate bar? Your treat may not make it home from the store safely without the help of your trusty InsulTote liner.
  4. Make InsulTote Pay!– Paperclip a little cash to the InsulTote liner when you’re done with it. Next time, if you remember to take the InsulTote in, use that cash for your treat. No bags, no treat! That’ll teach ya!
  5. Unload/Reload!- After unpacking your InsulTote liner and re-usable bags, immediately organize them into the brightest one and hang it on the door handle. This way you will remember to return them to the car the next time you leave the house. 
  6. Have back-ups!-No matter how good our intentions are, we are going to forget the InsulTote liners. Make sure you have a couple of extra InsulTote liners that live in your car (separate for hot and cold items. If you have a favorite trick for re-using your InsulTote liners, or tips to remember to take them into the store; please share with us on Facebook!

Pro Tip: If the tape on the InsulTote flap has seen better days, simply cut that flap off with household scissors. For short trips from the grocery store, you can simply fold the InsulTote liner over to keep closed. For longer trips, or to re-use them for shipping, you can use clear packing tape to seal them closed before shipping.