A simple side-by-side experiment has demonstrated the difference spray foam insulation can make to temperature retention in shipping containers, with an insulated container remaining 6°C warmer overnight than an uninsulated container.
The test compared two shipping containers parked alongside each other under the same conditions. One container had no insulation, while the other was insulated with approximately 1½ to 2 inches of spray foam.
Using temperature probes, the team measured how much the temperature dropped overnight to compare the performance of the two containers.
As explained in the video, the insulated container was coated with approximately 1½ to 2 inches of spray foam, with the presenter noting that the insulation provides around R6 to R7 ( R1.1 in NZ) per inch.
Following the overnight test, the results showed a noticeable difference between the two containers.
The presenter reported that the uninsulated container reached approximately 12°C, while the insulated container remained at around 18°C — a 6°C difference between the two containers.
While this was a single overnight test, the results demonstrate the potential for spray foam insulation to help maintain more stable internal temperatures in shipping containers.
For anyone converting a shipping container into a workshop, office, living space or storage facility, temperature control is an important consideration. The results highlight why insulation is worth considering when looking to create a more controlled internal environment.
At NZ Foam, we install closed-cell Heatlok HFO insulation in shipping containers to help improve thermal performance and manage condensation. Applied directly to suitable steel surfaces, the foam creates a continuous insulation layer that follows the container’s corrugated profile.
As interest in shipping container conversions continues to grow, choosing the right insulation system can make a meaningful difference to how the space performs throughout the year.
check out this video by the container guys explaining how temperature changes overnight https://www.youtube.com/shorts/rwXUzGMPiPg?si=QcsuyhQD1iKYZFGU
