Polyurethane panel thickness alone does not show cold room performance. Give suppliers the same room dimensions, internal and external design conditions, and use pattern for comparison.
Alongside thickness, request the maker's technical sheet, declared thermal conductivity and the test or conditions behind the value. Do not directly compare figures stated under different conditions.
Assess walls, ceiling, floor and door separately. Show panel joints, corners, floor connections and door perimeter in the drawing; include door traffic and surrounding conditions in the design calculation.
After installation, look for gaps, damage or sealing defects at joints. During commissioning, record instrument location, date and operating conditions; if readings differ from expectation, have the installation and door details checked.
Do not base selection only on centimetres or one wall reading. Have the design calculation checked against product data by the refrigeration designer and panel manufacturer.