Duplicating natural conditions, the humidity chambers create fluctuating moisture levels and temperatures to run temperate and humidity tests on samples. These environmental test chambers use recirculating air ducts to gently force water injected vapor throughout the chamber while the interior jacket and heated door prevent condensation from forming. Stainless steel humidity test chambers rapidly recover simulated environments after door is opened to minimize potential damage. The customizable microprocessor controls within the temperature chambers allow precise settings in any field for reproducible results.