Keep Warm! Micro-CT of Foam Insulation
Winter is here and the colder temperatures are likely raising your heating bills, as heating and cooling are said to account for 50-70% of energy bills.1 Ensuring that you have adequate insulation throughout your house, including your floors, walls, and ceilings, will decrease the amount of energy needed for heating and help lower your bills. Insulation types include foams, batts, blankets, and loose fill. We were curious and decided to take a closer look at rigid foam insulation on this micro scan.
Understanding Heat Transfer of Rigid Foam
As you may already know, heat can be transferred by three modes: conduction, convection, and radiation. Conduction is the transfer of heat through the excitement of atoms or molecules within solid objects and between them when they are touching. The better the conductor, the more heat is transferred. A second way to transfer energy, convection, occurs when warmer areas of a liquid or gas rise to cooler areas in the liquid or gas. The third way to transfer energy is by radiation, which occurs when heat moves by absorbing or giving off electromagnetic waves. This type of heat transfer warms objects over a distance because it does not need matter to move.2
With these basic concepts of heat transfer we can understand why many types of insulation are made to limit air movement. The rigid foam insulation we scanned is made of a micro cellular structure that effectively traps tiny pockets of air within its polymer foam walls. Air has a low conduction of heat, so air contributes as an insulator by effectively reducing changes in temperatures as long as convection can’t occur. The completely sealed cells of this foam insulation show that it is made to prevent convection and ensure good thermal resistance.2
Now you know what makes good rigid foam insulation, but what does it mean to you? When you purchase insulation, each product’s thermal resistance is stated as an R-Value. A higher R-Value means a better thermal resistance. Keep in mind the higher R-Value will likely mean a higher cost as well, so be sure to consult an expert to make sure you are selecting the right R-Value for the area of the home you wish to insulate.
We hope you enjoyed learning about foam insulation and how it works. If you have an image of the month you would like to contribute or suggest, feel free to e-mail email@example.com or call 610-366-7103.
- Insulation Fact Sheet. (2008). U.S. Department of Energy. Retrieved from: http://web.ornl.gov/sci/buildings/docs/factSheets/Insulation-FactSheet-2008.pdf
- Principles of Heating and Cooling. (2016). U.S. Department of Energy. Retrieved from: https://www.energy.gov/energysaver/principles-heating-and-cooling
NRecon, DataViewer, CTVox
Micro Photonics Imaging Laboratory, Allentown, PA