Our products are generally moulded or fabricated using 3mm ABS sheet. (0.17 w/m-k)
Supply air plenum boxes are insulated using 3mm class"O" closed cell foam (0.034 w/m-k)
We manufacture our plenums with an offset to the spigot locations. This is done to correspond with many air conditioning fan coil units where there is a blanking plate inside the unit to the side of the heat exchanging coil.
We offset the spigot outlets to correspond with a dead zone within
The spigot outlets on our plenum boxes are deliberately offset to correspond with a blanking plate situated on the inside of the fan coil unit.
A typical supply air plenum: