HVAC system control incorporating humidity and carbon monoxide measurement

Claim 1

An energy recovery apparatus in an environmental control system coupled to a controlled space comprising: an input terminal for receiving a signal indicative of a call for cooling from said controlled space; an output terminal for sending said signal indicative of a call for cooling from said controlled space to portions of an air conditioning unit; a humidity sensor located to sense humidity of said controlled space, said humidity sensor providing an output signal representative of the humidity in said controlled space; and a controller coupled to said humidity sensor and configured to selectively connect and disconnect said input terminal and said output terminal, wherein said controller is configured to maintain said input terminal and output terminal connected when said humidity of said controlled space is greater than a selected level, and wherein said controller is further configured to enable the periodic disconnection of said input terminal from said output terminal when said humidity is less than a selected level.