Indoor climate controller system adjusting both dry-bulb temperature and wet-bulb or dew point temperature in the enclosure

• US 5,346,129 A
• Filed: 05/17/1993
• Issued: 09/13/1994
• Est. Priority Date: 05/17/1993
• Status: Expired due to Term

• Current Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Original Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Inventors: Shah, Dipak J., Strand, Rolf L., Krueger, James H.
• Primary Examiner(s): Wayner, William E.
• Application Number:
  US08/061,516
• Time in Patent Office: 484 Days
• Field of Search: 62/176.6, 236/44 C, 236/44 A, 236/44 E, 165/20, 165/21
• US Class Current: 236/44.00C
• CPC Class Codes: F24F 11/0008 for air-humidification F24F11/30 takes precedence
• CPC Class Codes: F24F 11/30 for purposes related to the operation of the system, e.g. for safety or monitoring
• CPC Class Codes: F24F 11/63 Electronic processing
• CPC Class Codes: F24F 11/81 by controlling the air supply to heat-exchangers or bypass channels
• CPC Class Codes: F24F 11/86 by controlling compressors within refrigeration or heat pump circuits
• CPC Class Codes: F24F 2003/1446 by condensing
• CPC Class Codes: F24F 2110/10 Temperature
• CPC Class Codes: F24F 2110/20 Humidity
• CPC Class Codes: F24F 3/1405 in which the humidity of the air is exclusively affected by contact with the evaporator of a closed-circuit cooling system or heat pump circuit
• CPC Class Codes: G05D 22/02 characterised by the use of electric means

Abstract

A controller for a climate control system has a humidity (wet-bulb or dew point) temperature sensor as well as a dry-bulb temperature sensor within the enclosure. The humidity temperature value is used in connection with the dry-bulb temperature to generate a single error signal which is a function of both the dry-bulb and the humidity temperature values. This permits 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 humidity temperature, the humidity temperature can be synthesized from the relative humidity and dry-bulb temperature within the enclosure.

Claims

1. Apparatus for cooperating with a controller for a climate control system for modifying the temperature and humidity of air within an enclosure, said controller activating the climate control system responsive to a composite error value encoded in a composite error signal falling within a preselected range of error values, said apparatus comprising

a) a humidity sensor providing a humidity temperature signal encoding at least one of the wet-bulb temperature and the dew point temperature;

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 humidity temperature set point value, and providing a set point signal encoding the dry-bulb and humidity temperatures set point values; and

d) error computation means recieving the humidity and air temperature signals and the set point signal, for computing the composite 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 composite error value in the composite error signal.

2. The apparatus of claim 1 further comprising an error processing means receiving the composite error signal for providing a demand signal during intervals determined as a function of the composite error value.

3. The apparatus of claim 2, wherein the memory further comprises means for storing a limit dry-bulb temperature value and for providing a signal encoding the limit dry-bulb temperature value in a limit temperature signal, and wherein the error processing means further comprises comparison means receiving the limit temperature signal and the air temperature signal, for comparing the limit dry-bulb temperature with the value encoded in the air temperature signal, and for suppressing the demand signal responsive to a predetermined relationship between the limit dry-bulb temperature value and the dry-bulb temperature value.

4. The apparatus of claim 3 intended for controlling operation of a climate control system having an air conditioning function, wherein the means for storing a limit dry-bulb temperature value includes means for storing a temperature value less than the dry-bulb temperature set point value.

5. The apparatus of claim 1, wherein the humidity sensor comprises

a) a relative humidity sensor providing a relative humidity signal encoding the value of the ambient relative humidity;

and

b) humidity temperature computation means receiving the air temperature signal and the relative humidity signal, for computing a humidity temperature approximation value, and for encoding the humidity temperature approximation value in the humidity temperature signal.

6. The apparatus of claim 5, wherein the memory further comprises means for recording a relative humidity set point value, and means receiving the relative humidity set point value and the dry-bulb temperature set point value, for computing the humidity temperature set point value as a function of the relative humidity set point value and the dry-bulb temperature set point value, and for providing a signal encoding the computed humidity temperature set point value, and wherein the memory includes means receiving the computed humidity temperature set point value signal, for recording the computed humidity temperature set point value encoded in the computed humidity temperature set point value signal.

7. The apparatus of claim 1, wherein the memory further comprises i) means for recording a relative humidity set point value, and ii) computed set point recording means for recording a computed humidity temperature set point value encoded in a computed humidity temperature set point value signal, and iii) means for encoding the computed humidity temperature set point value as the humidity temperature set point value in the set point signal;

and wherein the controller further comprises computing means receiving the relative humidity set point value and the dry-bulb temperature set point value, for computing the humidity temperature set point value as a function of the relative humidity set point value and the dry-bulb temperature set point value, and for providing the signal encoding the computed humidity temperature set point value to the computed set point recording means.

8. The apparatus of claim 7, wherein the error computation means further comprises

i) computing means for forming a humidity temperature error equal to the difference between the humidity temperature value and the humidity temperature set point value, for forming a dry-bulb temperature error equal to the difference between the dry-bulb temperature value and the dry-bulb temperature set point value, and for providing an initial error signal encoding the humidity temperature error and the dry-bulb temperature error;

and

3 ii) comparison means receiving the initial error signal, for sensing the relative magnitudes of the humidity temperature error and the dry-bulb temperature error and for encoding in the composite error signal, the larger of the errors encoded in the initial error signal.

9. The apparatus of claim 1, wherein the error computation means further comprises

i) computing means for forming a humidity temperature error equal to the difference between the humidity temperature value and the humidity temperature set point value, for forming a dry-bulb temperature error equal to the difference between the dry-bulb temperature value and the dry-bulb temperature set point value, and for providing an initial error signal encoding the humidity temperature error and the dry-bulb temperature error;

and

ii) comparison means receiving the initial error signal, for sensing the relative magnitudes of the humidity temperature error and the dry-bulb temperature error and for encoding in the composite error signal, the larger of the errors encoded in the initial error signal.