The panels we used on walk in temperature humidity test chamber is Polyurethane panel.
It consists of SII, foaming polyurethane, color coated metal sheet and stainless steel, the best advantage of this kind of polyurethane panels is good temperature resistance ability, normally the temperature inside of the walk in temperature is very low, up to -60℃, even -70℃, but the ambient temperature will be high, up to +35℃ at the summer time in most countries, that means the temperature difference more than 100℃ from inside of panel and outside of the panel, but with good temperature resistance ability, you can’t feel the panel is cold when inside is -70℃.
Also at high temperature test, inside temperature is 120℃, you can’t feel the any high temperature of the panels from outside touching.
The density of this kind of polyurethane 41±3kg/m3, it can be thicker as per special requests. Heat conduction coefficient is 0.018~0.024w/(m.k). Because the fire retardant has been added into the polyurethane, it can’t get fire easily, the ignition temperature is more than 250℃.
This is the panel structure of our walk in temperature humidity test chamber: