Enthalpy based thermal comfort controller
AssigneeHoneywell Inc.
InventorDipak J. Shah
Life of this patent
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Abstract
A controller for a climate control system has a relative humidity sensor as well as a dry-bulb temperature sensor within the enclosure. The humidity value is used in conjunction with the dry-bulb temperature to generate an enthalpy error signal which is a function of both the dry-bulb temperature and the relative humidity values. This permits robust control of both enclosure temperature and enclosure humidity without abnormal cycling of the climate control system. Instead of using a sensor which directly measures the enthalpy, the enthalpy can be synthesized from the relative humidity and dry-bulb temperature within the enclosure. Alternately, the sensed and set point enthalpy values can be synthesized from any two thermodynamic properties of the moist air within the enclosure.
Claims14
Apparatus for cooperating with a controller for a climate control system for modifying the temperature and moisture content of air within an enclosure, said controller activating the climate control system responsive to an enthalpy error value encoded in an enthalpy error signal, said apparatus comprising:
- a) a relative humidity sensor providing a relative humidity signal encoding the relative humidity value;
- b) a temperature sensor providing an air temperature signal encoding the dry-bulb temperature value;
- c) a memory recording a dry-bulb temperature set point value and a relative humidity set point value, and providing a set point signal encoding the dry-bulb temperature and relative humidity set point values;
- and
- d) error computation means receiving the humidity and air temperature signals and the set point signals, for computing the enthalpy error value as a function of the values encoded in the humidity and air temperature signals and the set point signal, and for encoding the enthalpy error value in the enthalpy error signal.
Apparatus for cooperating with a controller for a climate control system for modifying the temperature and moisture content of air within an enclosure, said controller activating the climate control system responsive to an enthalpy error value encoded in an enthalpy error signal, said apparatus comprising:
- a) a enthalpy sensor providing a sensed enthalpy signal encoding the sensed enthalpy value;
- b) a memory recording a enthalpy set point value and providing a enthalpy set point signal encoding the enthalpy set point value;
- and
- c) error computation means receiving the sensed enthalpy signal and the enthalpy set point signal, for computing the enthalpy error value as a function of the values encoded in the sensed enthalpy signal and the enthalpy set point signal, and for encoding the enthalpy error value in the enthalpy error signal.
Apparatus for cooperating with a controller for a climate control system for modifying the temperature and moisture content of air within an enclosure, said controller activating the climate control system responsive to an enthalpy error value encoded in an enthalpy error signal, said apparatus comprising:
- a) a means for determining the space enthalpy by sensing any two thermodynamic properties of the moist air within the enclosure and providing a sensed enthalpy signal encoding the sensed enthalpy value;
- b) a memory recording set point values for any two thermodynamic properties of the moist air from which can be deduced an enthalpy set point value and providing a enthalpy set point signal encoding the enthalpy set point value;
- and
- c) error computation means receiving the sensed enthalpy signal and the enthalpy set point signal, for computing the enthalpy error value as a function of the values encoded in the sensed enthalpy signal and the enthalpy set point signal, and for encoding the enthalpy error value in the enthalpy error signal.
Dependencies are inferred from the claim text.