At the point of sale where I want to order these insulation boards, I was told that the gas present in the PIR insulation boards [polyisocyanuraatschuim] disappears, partially, after x number of years. Has this ever been tested in a lab?
Answer
Dear Rudi,
I am certainly not a specialist in insulation materials, but since your question has not yet been answered, I will give the following reasoning.
Presumably, certain gases are released during the production of PIR, which then become trapped in the structure of the material. Because it is exceptionally difficult to make a material perfectly leak-tight, I can imagine that these gases will be released over time. When that happens, the gas is replaced by air. If not, a negative pressure would arise, which is not possible since the material is not leak-tight. Besides, a negative pressure in the material would only increase its thermal resistance.
Because stagnant air is a very good insulator, I cannot imagine that the insulation value of PIR plates decreases significantly over the years. Air retention is the most important property of insulation. It is the layer of air in insulation materials through which a good thermal resistance is obtained.
In summary, I can imagine that certain gases are released, but this will (virtually) have no effect on the insulation value.
Regards,
Jeroen Engelen
Answered by
Ir. Jeroen Engelen
architecture engineering
Boeretang 200, 2400 Mol
http://www.sckcen.be
.