The trapped air pockets offer a good thermal insulation. To avoid convection currents, insulation chunks could be stuffed between the duct wall and the cover plate and between the access door covers.
Note This version is not suitable for temperatures above 80°C. For such cases we recommend the METU insulated access doors IRD-3DE
Data Sheet
Gasket Properties
Tender Texts
Opening Dimensions
IRD Cover Plate Information
Instructions
Instructions
Installation Video
Stainless steel version: use a stainless steel lubricant to prevent seizing.