초록 ▼

Relatively constant temperatures are maintained in a space by varying the capacity of heating or cooling equipment. A proportional band is used to adjust capacity to compensate for changes in heating or cooling load, and the proportional band is adjusted to bring the actual temperature within the sp

Relatively constant temperatures are maintained in a space by varying the capacity of heating or cooling equipment. A proportional band is used to adjust capacity to compensate for changes in heating or cooling load, and the proportional band is adjusted to bring the actual temperature within the space closer to the set point temperature. Such an adjustment may be made by determining the difference between the present temperature and the set point temperature, and adjusting a floating temperature set point by a percentage (e.g., ten percent) of the difference. Such a process may be repeated, for example, at regular intervals, such as once per minute. As a result, the temperature within the space approaches (e.g., asymptotically) the set point temperature whether the heating or cooling load is high or low. Methods, systems, and apparatuses are contemplated, including HVAC units and controls, including for residential applications, including using variable-speed drives.

대표청구항 ▼

What is claimed is: 1. An apparatus for maintaining a substantially constant temperature within a space within an enclosure, the apparatus comprising: a variable-capacity temperature changing system for changing the temperature within the space by at least one of adding heat to or removing heat fro

What is claimed is: 1. An apparatus for maintaining a substantially constant temperature within a space within an enclosure, the apparatus comprising: a variable-capacity temperature changing system for changing the temperature within the space by at least one of adding heat to or removing heat from the space; a temperature sensor positioned and configured to sense a present temperature within at least one of the space or air drawn from the space; an input device configured to receive an input temperature set point from an operator of the temperature changing system; a controller that is in communication with the input device and in control of the variable-capacity temperature changing system, wherein the controller is configured to automatically continuously gradually change the capacity of the variable-capacity temperature changing system so that the temperature within the space asymptotically approaches the input temperature set point, and wherein the controller comprises: a first control means for changing the capacity of the variable-capacity temperature changing system over a range of present temperatures within the space, wherein the first control means provides a maximum capacity at a first end of the range, a minimum capacity at a second end of the range, and at least two gradually differing intermediate capacities between the ends of the range, and a second control means for automatically moving the range, wherein the second control means moves the range less frequently than the first control means changes the capacity. 2. The apparatus of claim 1 wherein the second control means moves the range based on a difference between the present temperature and the input temperature set point. 3. The apparatus of claim 1 wherein the controller comprises a digital processor and the variable-capacity temperature changing system for changing the temperature within the space comprises: a compressor configured to compress a refrigerant; a condenser configured to cool and condense the refrigerant after the refrigerant is compressed by the compressor; an expansion device having an inlet and an outlet and configured to pass the refrigerant from the inlet to the outlet while maintaining a substantially higher pressure at the inlet than at the outlet; an evaporator coil positioned and configured to receive the refrigerant from the expansion device and to cool supply air to be delivered to the space; a first fan positioned and configured to move the supply air through the evaporator coil and to the space; a second fan positioned and configured to move outside air through the condenser; a first electrical motor connected to and configured to turn the first fan; a second electrical motor connected to and configured to turn the second fan; a third electrical motor connected to and configured to turn the compressor; at least one variable-speed drive unit configured and electrically connected to drive at least the third electrical motor at least three different speeds. 4. A direct expansion air conditioning unit for cooling a space within an enclosure and maintaining a substantially constant temperature within the enclosure, the air conditioning unit comprising: a compressor configured to compress a refrigerant; a condenser configured to cool and condense the refrigerant after the refrigerant is compressed by the compressor; an expansion device having an inlet and an outlet and configured to pass the refrigerant from the inlet to the outlet while maintaining a substantially higher pressure at the inlet than at the outlet; an evaporator coil positioned and configured to receive the refrigerant from the expansion device and to cool supply air to be delivered to the space; a first fan positioned and configured to move the supply air through the evaporator coil and to the space; a second fan positioned and configured to move outside air through the condenser; a first electrical motor connected to and configured to turn the first fan; a second electrical motor connected to and configured to turn the second fan; a third electrical motor connected to and configured to turn the compressor; at least one variable-speed drive unit configured and electrically connected to drive at least the third electrical motor at least three different speeds; a temperature sensor positioned and configured to sense a present temperature within at least one of the space or return air drawn from the space; an input device configured to receive an input temperature set point from an operator of the air conditioning unit; a controller that is in communication with the input device and the at least one variable-speed drive unit, wherein the controller is configured to control the speed of at least the third electrical motor, wherein the controller is configured to cause the at least one variable-speed drive unit to increase the speed of at least the third electrical motor as the present temperature increases, and to cause the at least one variable-speed drive unit to decrease the speed of at least the third electrical motor as the present temperature decreases, and wherein the controller selects a present speed of at least the third electrical motor using a floating temperature set point, wherein the controller is configured to change the floating temperature set point based on whether the present temperature is above or below the input temperature set point. 5. The air conditioning unit of claim 4 wherein the controller is configured to increase the floating temperature set point if the present temperature is below the input temperature set point, the controller is configured to decrease the floating temperature set point if the present temperature is above the input temperature set point, and the controller is configured to change the floating temperature set point at regular intervals of time. 6. The air conditioning unit of claim 4 wherein the controller is configured to change the floating temperature set point by a predetermined percentage of a difference between the input temperature set point and the present temperature. 7. The air conditioning unit of claim 4 wherein the first electrical motor is a variable-speed motor, and wherein the speed of the first electrical motor increases as the present temperature increases, and the speed of the first electrical motor decreases as the present temperature decreases. 8. The air conditioning unit of claim 7 wherein the second electrical motor is a variable-speed motor, and wherein the speed of the second electrical motor increases as the present temperature increases, and the speed of the second electrical motor decreases as the present temperature decreases. 9. The air conditioning unit of claim 4 comprising a single enclosure for the air conditioning unit, wherein the compressor, the condenser coil, the expansion device, the evaporator coil, the first fan, the second fan, the first electrical motor, the second electrical motor, the third electrical motor, and the at least one variable-speed drive unit are all located within the single enclosure, wherein the controller comprises a digital processor, and wherein the air conditioning unit is marketed for residential applications. 10. A building comprising the air conditioning unit of claim 4, wherein the building forms the enclosure. 11. A method of maintaining a substantially constant temperature within a space within an enclosure by controlling a variable-capacity temperature changing system to change the temperature within the space by at least one of adding heat to or removing heat from the space, the method comprising at least the acts of: inputting an input temperature set point; using an automated process, measuring a present temperature within the space; using an automated process, using at least the present temperature within the space, varying the capacity of the variable-capacity temperature changing system over at least part of a capacity range, wherein the capacity range extends from a minimum capacity, through at least two intermediate capacities, to a maximum capacity, and wherein the capacity range corresponds to a temperature range, wherein the temperature range extends from a first end temperature, through at least two intermediate temperatures, to a second end temperature, wherein the first end temperature corresponds to the minimum capacity and the second end temperature corresponds to the maximum capacity, and wherein the input temperature set point is in between the first end temperature and the second end temperature of the temperature range; using an automated process, repeating multiple times the varying of the capacity of the variable-capacity temperature changing system over at least part of the capacity range; using an automated process, using at least the present temperature within the space and the input temperature set point, adjusting the temperature range to bring the present temperature closer to the input temperature set point, wherein the adjusting of the temperature range includes changing the temperature at which a particular capacity corresponds, for at least two of the capacities within the capacity range. 12. The method of claim 11 further comprising, using an automated process, repeating multiple times the adjusting the temperature range to bring the present temperature closer to the input temperature set point. 13. The method of claim 11 wherein, in the varying of the capacity of the variable-capacity temperature changing system over a capacity range, the temperature range consists of at least four discrete capacity increments, the temperature range consists of at least four discrete temperature increments, each of the temperature increments has a corresponding capacity increment, each of the capacity increments has a corresponding temperature increment, and from the minimum capacity to the maximum capacity, each capacity increment has a higher capacity than the previous capacity increment. 14. The method of claim 11 wherein, in the adjusting of the temperature range to bring the present temperature closer to the input temperature set point, the adjusting includes moving the temperature range by a percentage of a difference between the present temperature within the space and the input temperature set point, wherein the percentage is greater than zero percent and less than 100 percent. 15. The method of claim 14 wherein, in the adjusting of the temperature range to bring the present temperature closer to the input temperature set point, the percentage is greater than two percent and less than 50 percent. 16. The method of claim 11 wherein, in the adjusting of the temperature range to bring the present temperature closer to the input temperature set point, the adjusting is performed at substantially regular intervals of time, wherein the intervals of time are greater than one second and less than one hour. 17. The method of claim 11 further comprising at least one of obtaining or providing an air conditioning unit, wherein the air conditioning unit is the variable-capacity temperature changing system, wherein the air conditioning unit has a variable-speed compressor, and wherein the varying of the capacity of the variable-capacity temperature changing system over a capacity range includes varying the speed of the compressor. 18. The method of claim 11 further comprising the acts of: using an automated process, using the present temperature within the space, determining a present capacity at which to operate the HVAC unit wherein the present capacity changes relative to an offset of the present temperature within the space from a floating temperature set point; using an automated process, operating the HVAC unit at the present capacity; using an automated process, repeating multiple times the measuring of the present temperature, the determining of the present capacity, and the operating at the present capacity; using an automated process, changing the floating set point based on the input temperature set point and the present temperature within the space; and using an automated process, repeating multiple times the measuring of the present temperature, the determining of the present capacity, the operating at the present capacity, the repeating of the measuring, the determining, and the operating, and the changing of the floating temperature set point. 19. The method of claim 18 wherein the changing of the floating temperature set point is performed at regular intervals of time. 20. The method of claim 18 wherein the changing of the floating temperature set point comprises changing the floating temperature set point by a predetermined percentage of a difference between the input temperature set point and the present temperature. 21. The method of claim 18 wherein the HVAC unit comprises a variable-speed compressor, and the operating of the HVAC unit at the present capacity includes controlling the speed of the compressor, wherein the determining of the present capacity includes selecting a lower speed of the compressor as the present temperature decreases, and wherein the determining of the present capacity includes selecting a higher speed of the compressor as the present temperature increases. 22. The method of claim 21 wherein the HVAC unit comprises an evaporator coil and a first fan configured and positioned to move air through the evaporator coil and to the space, and wherein the operating of the HVAC unit at the present capacity includes controlling the speed of the first fan, wherein the determining of the present capacity includes selecting a lower speed of the first fan as the present temperature decreases, and wherein the determining of the present capacity includes selecting a higher speed of the first fan as the present temperature increases. 23. The method of claim 11 wherein the capacity range extends in capacity increments, the temperature range extends in at least four temperature increments, and the input temperature set point is closer to one end of the temperature range than to the other end of the temperature range. 24. The method of claim 23 wherein, in the varying of the capacity of the variable-capacity temperature changing system over a capacity range, each of the temperature increments has a corresponding capacity increment, each of the capacity increments has a corresponding temperature increment, and the temperature increments and the capacity increments vary with a consistently positive slope from the minimum capacity to the maximum capacity and from the first end temperature to the second end temperature. 25. The method of claim 23 further comprising at least one of obtaining and or providing an air conditioning unit, wherein the air conditioning unit is the variable-capacity temperature changing system, wherein the air conditioning unit has a variable-speed compressor, and wherein the varying of the capacity of the variable-capacity temperature changing system over a capacity range includes varying the speed of the compressor.