Comfort control system and method factoring mean radiant temperature

Claim 1

A comfort control system for modifying the operating temperature for an environment to be controlled characterised by:- (a) an input means for inputting a selected temperature of the environment to a microprocessor means; (b) temperature sensor means (30) for sensing the temperature in the environment to be controlled and supplying an electrical signal indicative of said sensed temperature to a microprocessor means; (c) relative humidity sensor means (40) for sensing the relative humidity in the environment to be controlled and supplying an electrical signal indicative of said sensed relative humidity to a microprocessor means; (d) building load monitoring means (50) for monitoring a characteristic indicative of the exterior building load on the environment to be controlled and supplying an electrical signal indicative of said characteristic to a microprocessor means; and (e) microprocessor means (60) electrically interconnected with the input means, temperature sensor means, relative humidity sensor means, and building load monitoring means and under software control for: (i) calculating an operating temperature set point for the environment to be controlled based on a predetermined equation and derived from the selected temperature inputted from the input means, the temperature sensed by the temperature sensor means, the relative humidity sensed by the relative humidity sensor means, and the characteristic indicative of the building load monitored by the building load monitoring means; (ii) comparing said operating temperature set point to the temperature sensed by the temperature sensor means; and (iii) generating a suitable control signal for an HVAC unit derived from the comparison between the calculated current operating temperature set point and the temperature sensed by the temperature sensing means.

Claim 4

A system according to any preceding Claim, characterised in that the building load monitoring means (50) comprises means for monitoring the duty cycle of the control system.

Claim 5

A system according to any preceding Claim, characterised in that the predetermined equation used by said microprocessor means (60) for calculating the operating temperature set point is the following formula: S = T p - K₁ D + (K₂ - RH s ) K₃ where S equals the operating temperature set point, T p indicates the selected temperature of the environment input at the input means, D indicates the duty cycle, RH s indicates the relative humidity sensed by the relative humidity sensor means, and K₁, K₂ and K₃ indicate selected constants.

Claim 7

A system according to any of Claims 3 to 6 characterised in that L b is calculated as the ratio of the difference between the temperature outside the environment to be controlled and the temperature inside the environment to be controlled divided by a constant value.

Claim 8

A system according to any of Claims 3 to 7 characterised by means for adjusting the constant values K₁, K₂ and K₃ used in the operating temperature set point calculation formula.

Claim 9

A method of controlling the comfort of a room or other environment characterised by the steps of: (a) sensing the air temperature and relative humidity of the room or other environment to be controlled; (b) monitoring a characteristic of the environment to be controlled which is indicative of the building load of the room or other environment to be controlled; (c) accessing information indicative of the selected temperature of the environment and constant values indicative of the modification of the operation set point selected as a result of the sensed relative humidity and the monitored building load-indicative characteristic; (d) calculating the operating temperature set point of the room or other environment to be controlled in accordance with a calculation formula which incorporates the selected room temperature, the sensed relative humidity, the monitored characteristic indicative of building load, and the accessed constant values; (e) comparing the calculated operating temperature set point with the sensed room temperature; and (f) generating a control signal for the comfort control system dependent on the comparison of the calculated operating temperature set point and the sensed room temperature.

Claim 12

A method according to any of Claims 9 to 11 characterised in the step of calculating comprises the step of using the following calculation formula: S = T p - K₁ L b + (K₂ - RH s ) K₃ where S equals the operating temperature set point, T p indicates the selected temperature input at the input means L b indicates the building load derived from the characteristics monitored by the building load monitoring means, RH s indicates the relative humidity sensed by the relative humidity sensor means, and K₁, K₂, and K₃ indicate constants.