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Oklahoma State University

Low Temperature Psychrometric Chamber

The low temperature psychrometric chamber artificially reproduces the temperature and relative humidity of various climates around the world, from tropical to continental, from dry desert to northern and polar tundra. The temperature can range from -40 to +130°F (-40 to 55°C) and the relative humidity from 10 to 95% R.H.
This psychrometric chamber is used to experimentally study the behavior of systems and components under specific ambient conditions.  Primarily intended for testing heat pumps, refrigeration systems, and unitary equipment up to 20 tons (70 kW) of refrigerating capacity, the facility consists of two similar-size adjacent rooms of about 19 by 20 by 18 feet high. The large floor area can accommodate multiple set ups inside each room. A double panel sliding door (shown in figure here) is located next to a gantry crane, which is used to position the testing equipment inside the chamber.
A large amount of support was given by AAON, an Oklahoma manufacturer of heating and cooling products. AAON is well known for their rooftop air conditioning units. The rooms are now part of the regular Thermal Systems Lab tour, with a donated unit available for demonstrations.
Several students that worked with AAON on the psychrometric room design are now employed at AAON’s main location.