ECONOMIZER CONTROL
First Claim
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 based on 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;
if 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.
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Accused Products
Abstract
The present disclosure provides a method for operating an HVAC system for conditioning air of an inside space. The HVAC system has an economizer configured to control the intake of outside air into an HVAC air stream of the HVAC system. The method includes determining at least two parameters of the air of the inside space, where the at least two parameters are 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. The method also includes determining at least two parameters of the outside air, where 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. Based on 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, a determination is made of whether dehumidification of the inside space is needed, and if dehumidification is not needed, the economizer is commanded 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. If, alternatively, dehumidification is needed, the economizer is commanded to increase the intake of outside air into the HVAC air stream if the outside air enthalpy is less than the enthalpy reference, and if the outside air dew point is less than a dew point reference.
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Citations
20 Claims
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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:
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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 based on 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; if 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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method for economically operating an HVAC system for conditioning air in an inside space, the HVAC system having an economizer configured to control the intake of outside air that is mixed with a return air stream to form a mixed air stream, the method comprising:
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determining whether dehumidification of the air in the inside space is needed; when dehumidification is not needed, increasing the intake of the outside air if mixing the outside air with the return air will result in a mixed air stream dry bulb temperature that is lower than a return air stream dry bulb temperature, without resulting in a mixed air stream enthalpy becoming greater than a return air stream enthalpy. - View Dependent Claims (16, 17)
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18. An HVAC system for economically conditioning air of an inside space, comprising:
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an economizer configured to control the intake of outside air into an HVAC air stream of the HVAC system; a controller configured to control the relative amount of outside air that is provided by the economizer to the HVAC air stream; one or more sensors for measuring 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; one or more sensors for measuring 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; wherein, if dehumidification is needed, the controller is configured to increase the intake of outside air into the HVAC air stream if the outside air enthalpy is less than an enthalpy reference and if the outside air dew point is less than a dew point reference. - View Dependent Claims (19, 20)
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Specification