Abstract: An environmental test chamber, and method of providing an environmental test chamber, includes combining an equipment module made up of an equipment housing and air treatment equipment in the equipment housing with a selected one or more of a plurality of chamber modules connected with the equipment module to provide the environmental test chamber. The equipment housing includes an opening defining an airflow passage and an airflow path extending to the airflow passage. The air treatment equipment includes air moving equipment flowing air along the airflow path through the airflow passage and air-conditioning equipment in the flow path. The air treatment equipment includes one or more of (i) heating equipment for selectively heating the flowing air, (ii) cooling equipment for selectively cooling the flowing air, (iii) humidification equipment for selectively humidifying the flowing air, and/or (iv) dehumidification equipment for selectively dehumidifying the flowing air.

Abstract: A climatic test system includes a test chamber adapted to hold a unit under test within the housing, and a refrigeration system that is adapted to cool air within the chamber. The refrigeration system includes a high stage, a low stage, and a cascade heat exchanger between said high and low stages. The low stage includes a refrigeration cycle having a low stage compressor, a low stage condenser, a low stage expansion device, and a low stage evaporator. The low stage evaporator is in heat exchange relationship with the chamber. The high stage includes a refrigeration cycle having a high stage compressor, a high stage condenser, and a cascade heat exchanger evaporator that is in heat exchange relationship with the low stage condenser, thereby defining the cascade heat exchanger. The high stage further has a first high stage expansion device supplying refrigerant from the high stage condenser to the cascade heat exchanger evaporator during cascade operation.

Abstract: An environmental test chamber, and method of testing a response of a unit-under-test to treated air, includes a housing having an enclosing wall defining a test bay with an access opening in the wall providing access to the test bay and a closure selectively covering the opening. An airflow plenum supplies treated air to the test bay. An air treatment system treating air flowing through the plenum. A control operates the air treatment system to flow treated air through the plenum in two selective modes. The air treatment system flows treated air in a first flow direction through the test bay in one of the modes and flows air in a second flow direction through the test bay in a second of the modes. The first and second flow directions are different from each other.

Abstract: An environmental test chamber, and method of testing a response of a unit-under-test to treated air, includes a housing having an enclosing wall defining a test bay with an access opening in the wall providing access to the test bay and a closure selectively covering the opening. An airflow plenum supplies treated air to the test bay. An air treatment system treating air flowing through the plenum. A control operates the air treatment system to flow treated air through the plenum in two selective modes. The air treatment system flows treated air in a first flow direction through the test bay in one of the modes and flows air in a second flow direction through the test bay in a second of the modes. The first and second flow directions are different from each other.