Modified Atmosphere Insulation (MAI) panels are currently in development. Here, an MAI panel is connected to a vacuum-pump assembly for testing.
Photo: Dr. Kaushik Biswas
Modified Atmosphere Insulation
Modified Atmosphere Insulation (MAI) is a good candidate for next-generation insulation materials and is a lower cost alternative to current vacuum insulation materials. Research is on track to create a composite insulated metal sandwich panel that achieves R-11 per inch This would almost double the R-value of the best insulated metal panel available on the market today.
MAI technology is a cousin of the vacuum insulated panel (VIP), where sucking all the air out of panels and sealing them tightly achieve extremely high insulation values. The vacuum in MAI panels is mainly created by condensation of steam that replaces air. It is sealed at atmospheric pressure using standard equipment at a much faster rate. The core is evacuated to 50 mbar (~seconds), followed by replacement of air with steam. Condensation of the steam during the final cool forming step creates the final vacuum (~ 5mbar).
Overall, Modified Atmosphere Insulation provides similar performance as other types of vacuum insulation panels, at 40-50% less cost. Adding R-20 insulation to the walls of new homes and U.S. existing homes built before 2010 would have an annual primary energy-saving potential of 769 trillion Btus, according to the project’s impact study at the Department of Energy’s Oak Ridge National Laboratory (ORNL).
MAI is being tested by ORNL researchers who are working with industry partners, NanoPore and Firestone Building Products.
Currently, the project is not on track to develop a new insulation board, but rather demonstrate and measure R-value of an insulated metal panel using a composite MAI/foam core. Succinctly, there isn't a Vacuum Insulation board almost ready for market in the home building industry.
Long-term performance retention for the lifetime of the building envelope ranges from 30-50 years. MAI panels will need to retain their high R-value over the life of the application – i.e. the barrier films will need to prevent loss of vacuum.
Damage to the MAI panels during or after installation is a concern as well. Optimization of the panel size will be needed to minimize the impact of damaged panels on overall R-value of the envelope component. Pre-fabricated components such as metal sandwich panels requiring minimal sizing and/or alterations on site will be necessary.