Our panelized walk-in test chambers use urethane-foam panels that lock together with cam latches. This is the same construction used for walk-in coolers in restaurants and supermarkets, but of a higher quality. The panels we use have a stainless steel interior skin to be stronger and impervious to extreme conditions. The seams between panels are carefully sealed to protect from leaking that may affect performance or damage the panels. Doors and windows have embedded heaters, as well.