How it Works: Heat Flow & Foam Insulation

Everyone knows that foam insulation and insulation in general helps keep the home temperate. But, how exactly? At Lewis Insulation, we are experts in all types of insulation, specializing in foam insulation for Eden Prairie and the surrounding areas. We get many questions about how insulation works and we’d like to share a brief rundown of the concepts of general heat flow as well as what makes foam insulation so good at what it does.

foam insulation

Conduction, Convection & Radiation

Conduction is the way in which heat moves through materials. Insulation’s job is to slow down this conductive heat flow and keep the heat from moving from outdoors to indoors.

Convection is the ways heat circulates through liquids and gasses. Hot air rises and cool air sinks. Home insulation slows convective heat flow.

Radiation is heat that travels in a straight line, heating anything solid that lies in its pathway. Home insulation reduces this acquisition of heat and is most effective when directed towards airflow.


Home insulation is integral in decreasing the flow of heat by offering resistance to the movement of it. In the cooler months, without insulation, hot air moves from heated areas to cooler areas of the home. The cold temperatures outside create the need for your home’s heating system to compensate for the loss of heat; constantly trying to fill in where heat has escaped. During the hotter months, cold air that is lost when heat enters and invades a space is then made up for by your home’s cooling system. It is your insulation’s job to stop this flow of heat and allow your systems to efficiently keep your home warm or cool. So, when open gaps in a building are filled with insulation, they reduce convective heat loss.

All types of insulation come with an “R-Value”, a rating applied to an insulation type’s ability to resist conductive heat flow. Closed cell spray foam insulation has one of the highest R-values on the market today.

Closed cell spray foam insulation works well in difficult to reach nooks and crannies, like attics and crawl spaces since it is sprayed onto these surfaces.

These are only a few reasons you should consider closed foam insulation for your home. Call us and we can tell you even more!

Are you interested in learning more about closed foam insulation for your Eden Prairie home? Call us at Lewis Insulation at 763-477-2612, or you can contact us and set up a Free Estimate.