Control and method for tempering supply air
AssigneeAmerican Standard Inc.
InventorsDoyoung Han, William G. Hansen
Life of this patent
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Abstract
A microprocessor based control for tempering supply air in a multi-stage temperature conditioning system. The temperature conditioning stages are normally controlled in response to a comfort temperature sensor to maintain the zone at a setpoint. However, if a sensor in the supply airstream indicates that the temperature of the supply air is less than a predetermined minimum, the primary control algorithm is overridden and the temperature conditioning stages are controlled to increase the supply air temperature. Tempering the supply air prevents personal discomfort due to excessively cold air being supplied to the zone.
Claims25
In a system having a plurality of temperature conditioning stages that may be selectively energized so the capacity of the system may be varied to maintain a comfort zone at a setpoint temperature, a control for tempering air supplied to the zone to prevent personal discomfort to occupants of the zone due to excessively cold air being supplied to the zone, said control comprising:
- a. comfort zone temperature sensor;
- b. a comfort zone temperature sensor;
- c. primary control means responsive to the comfort zone temperature sensor, for controlling the capacity of the temperature conditioning system by selectively energizing stages of temperature conditioning to maintain the comfort zone at the setpoint temperature;
- and
- d. secondary control means, responsive to the supply air temperature sensor, for preventing excessively cold air being supplied to the zone by overriding the primary control means and controlling the capacity of the temperature conditioning system to increase the supply air temperature if it should fall below a predetermined minimum value lying in the range from 40.degree. F. to 55.degree. F.
In a system having a plurality of heating and cooling stages that may be selectively energized in a heating mode or in a cooling mode to temperature condition a comfort zone to a setpoint temperature, a control for tempering air supplied to the zone, said control comprising:
- a. a supply air temperature sensor;
- b. a comfort zone temperature sensor;
- c. primary control means responsive to the comfort zone temperature sensor for placing the system in the heating or cooling mode and selectively energizing one or more of either the heating stages or the cooling stages to maintain the comfort zone at the setpoint temperature;
- and
- d. secondary control means for overriding the primary control means to increase the supply air temperature if it should fall below a predetermined minimum value by energizing an additional stage of heating in the heating mode, and by de-energizing a stage of cooling in the cooling mode.
In a system having a plurality of temperature conditioning stages that may be selectively energized to maintain a comfort zone at a setpoint temperature, a method of controlling the stages for tempering air supplied to the zone to prevent personal discomfort to occupants of the zone due to excessively cold air being supplied to the zone, said method comprising the steps of:
- a. sensing the supply air temperature;
- b. sensing the comfort zone temperature;
- c. in response to the comfort zone temperature, selectively energizing stages of temperature conditioning to maintain the comfort zone at the setpoint temperature according to a primary control;
- and
- d. preventing excessively cold air being supplied to the zone by overriding the primary control and controlling the stages of temperature conditioning to increase the supply air temperature if it should fall below a predetermined minimum value lying in the range from 40.degree. F. to 55.degree. F.
Dependencies are inferred from the claim text.