Patent ID: 8875528
Filing Date: 2014-11-04
Classification: F24F,F25B,F25D

Abstract:
1. A test chamber comprising: a structure defining a work space having air; a refrigeration system comprising: a heat exchanger positioned to communicate with the air in the work space; a compressor coupled to the heat exchanger and producing a hot fluid; a condenser coupled to the compressor and producing a liquid; a throttle valve coupled to the condenser and producing a cold fluid; and a controller for controlling a mixture of cold fluid and hot fluid entering the heat exchanger, wherein the controller includes a temperature-humidity mode in which the controller is programmed to control a flow rate of cold fluid mixing with the hot fluid at a first flow rate, and programmed to determine a temperature of air in the test chamber, and if the temperature of air in the test chamber is greater than a desired temperature range, the controller is programmed to increase the flow rate of cold fluid mixing with the hot fluid by a slight increment, said slight increment being designed to control a temperature differential between the mixture and air in the work space in order to control condensation formation on the heat exchanger so as to limit loss of humidity in the air in the work space, to reach a second flow rate that is greater than the first flow rate, programmed to monitor the temperature of air in the test chamber, and programmed to determine whether the temperature of air in the test chamber has decreased, and if the temperature of air in the test chamber has not decreased, the controller is programmed to further increase the flow rate of cold fluid mixing with the hot fluid by a slight increment to reach a third flow rate that is greater than the second flow rate and programmed to continue monitoring the temperature of air in the test chamber, determining if the temperature of air in the test chamber has decreased, and continuing increasing the flow rate of the cold fluid mixing with the hot fluid by a slight increment if the temperature of air in the test chamber has not decreased until a decrease in temperature is achieved, thereby the controller is controlling a ratio of cold fluid and hot fluid in the mixture to control a temperature differential between the mixture and air in the work space in order to control condensation formation on the heat exchanger.