Patent ID: 9097432
Filing Date: 2015-08-04
Classification: F24F

Abstract:
1. A method for operating an HVAC system for conditioning air of an inside space, the HVAC system having an economizer configured to control the intake of outside air into an HVAC air stream of the HVAC system, the method comprising: determining at least two parameters of the air of the inside space, the at least two parameters being selected from a set of parameters from which an inside air dry bulb temperature, an inside air dew point, an inside air relative humidity, and an inside air enthalpy can be determined, either directly or indirectly; determining at least two parameters of the outside air, the at least two parameters being selected from a set of parameters from which an outside air dry bulb temperature, an outside air dew point, and an outside air enthalpy can be determined, either directly or indirectly; determining whether dehumidification of the inside space is needed or not needed by comparing one or more of the inside air dry bulb temperature, the inside air dew point, the inside air relative humidity, and the inside air enthalpy with a predetermined setpoint; and if it is determined that dehumidification is not needed, commanding the economizer to increase the intake of outside air into the HVAC air stream if the outside air dry bulb temperature is less than a dry bulb temperature reference, and if the outside air enthalpy is less than an enthalpy reference, even if the outside air dew point is above a dew point reference.