WO2025160060A1 - Using setpoint changes to defrost evaporator coils - Google Patents

Abstract

Exemplary embodiments are disclosed systems configured for using setpoint changes for defrosting evaporator coils. Also disclosed are exemplary methods of using setpoint changes for defrosting evaporator coils.

Description

USING SETPOINT CHANGES TO DEFROST EVAPORATOR COILS

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application is a PCT International Application that claims priority to and the benefit of U.S. Provisional Application No. 63/625,793 filed January 26, 2024. The entire disclosure of this provisional patent application is incorporated herein by reference.

FIELD

[0002] The present disclosure relates to using setpoint changes to defrost evaporator coils.

BACKGROUND

[0003] This section provides background information related to the present disclosure which is not necessarily prior art.

[0004] Defrost is a significant energy drain on a refrigeration system, especially low temperature evaporators. Efficiency of the refrigeration system will degrade as ice builds up on the evaporator coil over time, which leads to longer run times and increased power. Removal of the ice or frost from the evaporator coil is typically done by either electric heating elements or hot gas bypass. Conventionally, it is common to defrost on a time-based schedule.

DRAWINGS

[0005] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations and are not intended to limit the scope of the present disclosure.

[0006] FIG. 1 is a flow diagram of an exemplary method (or control logic) for using setpoint changes to defrost the evaporator coil according to exemplary embodiments disclosed herein.

[0007] FIG. 2 shows an example Case Controller 200 (CC200) that may be configured (e.g, via a firmware change, algorithmically configured via artificial intelligence (Al) machine learning algorithm(s), provided with application programming or software, etc.) to be operable for using setpoint changes to defrost the evaporator coil according to exemplary embodiments disclosed herein.

[0008] Corresponding reference numerals may indicate corresponding (though not necessarily identical) features throughout the several views of the drawings.

DETAILED DESCRIPTION

[0009] Example embodiments will now be described more fully with reference to the accompanying drawings.

[0010] When evaporator coils frost up over time, the efficiency of the evaporator coil heat transfer decreases. But as recognized herein, changing the evaporator saturation temperature or pressure to run above freezing and doing this more frequently than a traditional defrost, ice buildup on the evaporator coil can be minimized (or at least reduced) and removed quickly. Accordingly, exemplary embodiments were developed and/or are disclosed herein that use setpoint changes to defrost the evaporator coil. As disclosed herein, exemplary embodiments are configured to periodically change the evaporator setpoint (temperature or pressure) above freezing to melt the ice buildup on the evaporator coil.

[0011] When the evaporator saturated temperature is raised just above freezing, the ice buildup on the evaporator coil will melt. For example, the temperature setpoint for a case (e.g., walk-in freezer, walk-in cooler, other refrigerated cases or spaces, etc.) could be -25 °F. When a temperature setpoint defrost is initiated, the temperature setpoint could be raised to slightly above freezing, e.g., 33 °F to 35 °F, etc. Raising the temperature setpoint slightly above freezing will cause the ice to melt but not raise the product or space temperature dramatically. After the ice has been melted, the temperature setpoint would return to normal operation, which in this example is at -25 °F.

[0012] The determination to initiate or terminate a temperature setpoint defrost may be accomplished in various ways in exemplary embodiments. For example, the output from a sensor(s) (e.g., camera sensor, etc.) may be used in exemplary embodiments. But other exemplary embodiments are configured to not use any sensors for determining when to initiate or terminate a temperature setpoint defrost, which may advantageously provide a less complicated and more costeffect approach. [0013] In exemplary embodiments, quick defrost events are scheduled to occur on a more frequent time basis, e.g., once per hour possibly or based on an indoor temperature and humidity data. Machine learning algorithms may be implemented for better performance. The quick/brief defrost (e.g., micro defrost) events would prevent large amounts of ice buildup, and when ice does start to build up, that ice buildup can be removed quickly. With this approach, the product and space temperatures are likely to never see a noticeable change in temperature because of the short durations of raising the setpoints just above freezing (e.g., 33 °F to 35 °F, etc.). This approach may also allow for the elimination of other more costly forms of defrost, such as hot gas bypass or electric defrost that can be eliminated completely from the system.

[0014] The higher setpoint for defrost may be accomplished in various ways in exemplary embodiments. In exemplary embodiments, an evaporator pressure regulator (EPR), an evaporator pressure regulating valve, or an expansion device at an inlet to the evaporator may be used to obtain the higher setpoint for defrost in a typical low temperature system.

[0015] In exemplary embodiments, a scroll booster system may also be used that is especially suited for rapid evaporator setpoint changes. By shutting off a low temperature booster compressor, the suction temperature through the case becomes medium temperature pressure, and electronic expansion valve(s) (EPV) may adjust for the superheat as the pressure changes. An evaporator pressure regulator (EPR) may or may not be needed depending on the suction setpoint for the medium temperature compressor. When the defrost event has completed, the low temperature compressor would be restarted, and the system would return to normal operation.

[0016] From a controls perspective, a controller may be used to change the setpoint for defrost. The controller may comprise a local case controller or a supervisory controller (e.g., controller in the cloud or at the store, etc.) that communicates with (e.g., sends a signal back, etc.) to the evaporator to change the setpoint. The frequency of setpoint defrost changes may be initially setup to occur on a more frequent basis. But the frequency of setpoint defrost changes may also or later be optimized based on case temperature and humidity. For example, a case that is less humid will have less ice buildup, such that the temperature setpoint defrost changes may occur less frequently for defrost.

[0017] Advantageously, exemplary embodiment disclosed herein replace and eliminate traditional defrost cycles (e.g., hot gas bypass or electric defrost, etc.) with more efficient methods of changing temperature setpoints, which solves the problem of being able to defrost a coil only when needed. This, in turn, will increase overall system efficiency and save energy.

[0018] FIG. 1 illustrates an exemplary method 100 (or control logic) for using setpoint changes to defrost the evaporator coil. As shown, the method 100 includes detecting frost formation by a sensor 104, estimating frost formation based on time 108, and/or detecting frost formation algorithmically 112 by using relative humidity, temperature, and/or doors of a space (e.g., refrigerated case, etc.) in which the evaporator coil is being used.

[0019] After frost formation is detected or estimated, defrost of the evaporator coil is triggered or initiated at 116. Defrost of the evaporator coil is triggered or initiated at 120 by raising the temperature to a value (e.g., 33 °F to 35 °F, etc.) just above freezing to defrost the evaporator coil and/or by raising the saturation pressure to a value just above a pressure resulting in a temperature (e.g., 33 °F to 35 °F, etc.) just above freezing to defrost the evaporator coil. At 128 defrost of the evaporator coil is terminated.

[0020] By way of example, a controller disclosed herein may comprise a Case Controller 200 (CC200) controller (FIG. 2) that is configured to be operable for on demand initiation of a defrost cycle as disclosed herein. In such exemplary embodiments, the controller may include one or more features as disclosed in Appendix A to U.S. Provisional Application No. 63/625,793 filed January 26, 2024. The contents of U.S. Provisional Application No. 63/625,793 and its Appendix A are incorporated herein by reference in their entirety. Accordingly, exemplary embodiments may include a controller having one or more features identical to or similar to a CC200 controller. For example, an exemplary embodiment may include a controller that is a microprocessor-based controller for use in controlling temperature and Superheat in refrigerated fixtures and walk-in boxes. The controller may be suitable for medium and low temperature applications and can control all loads in a refrigerated box or fixture for up to three evaporator coils. These include lighting, fans, defrost heaters, solenoid valves, stepper valves, and pulse width modulation valves.

[0021] Exemplary embodiments disclosed herein (e.g., a CC200 controller (FIG. 2), other controller, etc.) may be used in various types of systems and applications, e.g., evaporators, walk-in freezers, walk-in coolers, other refrigerated cases or spaces, in the cloud, etc. Accordingly, the exemplary embodiments disclosed herein are not limited to use in any one particular type of system and/or refrigerated space, etc. Aspects of the present disclosure are also not limited to any particular type of refrigeration application as exemplary embodiments disclosed herein may be used with, incorporated into, or retrofit to any and all refrigeration applications that go through defrost. Exemplary embodiments disclosed herein may also be used with, incorporated into, or retrofit to heat pumps, scroll booster system, controllers, etc.

[0022] Exemplary embodiments are disclosed of systems for defrosting evaporator coils. In exemplary embodiments, the system comprises a controller that is configured to be operable for: monitoring the evaporator coil to determine if a defrost of the evaporator coil is required; after determining that defrost of the evaporator coil is required, initiating the defrost of the evaporator coil by: periodically changing an evaporator temperature setpoint to a value just above freezing to defrost the evaporator coil; and/or periodically changing an evaporator pressure setpoint to a value just above a pressure resulting in a temperature just above freezing to defrost the evaporator coil; and after determining that defrost of the evaporator coil is complete, terminating defrost of the evaporator coil by returning the evaporation temperature setpoint and/or the evaporator pressure setpoint to normal operation.

[0023] In exemplary embodiment, after the controller determines that defrost of the evaporator coil is required, the controller is configured to be operable for initiating the defrost of the evaporator coil by periodically changing the evaporator temperature setpoint to a value within a range from about 33 °F to about 35 °F to defrost the evaporator coil. For example, the controller may be configured to be operable for initiating the defrost of the evaporator coil by periodically changing the evaporator temperature setpoint from about -25 °F to the value within the range from about 33 °F to about 35 °F to defrost the evaporator coil; and after determining that defrost of the evaporator coil is complete, the controller is configured to be operable for returning the evaporation temperature setpoint to about -25 °F for normal operation.

[0024] In exemplary embodiments, after the controller determines that defrost of the evaporator coil is required, the controller is configured to be operable for initiating the defrost of the evaporator coil by periodically changing the evaporator pressure setpoint to the value just above the pressure resulting in a temperature within a range from about 33 °F to about 35 °F to defrost the evaporator coil. [0025] In exemplary embodiments, the controller is configured such that: a frequency at which the periodic changes to the evaporator temperature setpoint initially occurs is frequent; and/or a frequency at which the periodic changes to the evaporator pressure setpoint initially occurs is frequent. The controller may be configured such that: the frequency at which the periodic changes to the evaporator temperature setpoint initially occurs is at least once per hour; and/or the frequency at which the periodic changes to the evaporator pressure setpoint initially occurs is at least once per hour. The controller may be configured such that the frequency at which the periodic changes to the evaporator temperature setpoint and/or the frequency at which the periodic changes to the evaporator pressure setpoint is adjustable or optimizable based on one or more condition(s) of a space in which the evaporator coil is used including one or more of a temperature of the space, a humidity of the space, and/or door opening(s) of the space.

[0026] In exemplary embodiments, the controller is configured to be operable for determining whether to initiate or terminate defrost of the evaporator coil by using camera sensor output.

[0027] In exemplary embodiments, the controller is configured to be operable for determining whether to initiate or terminate defrost of the evaporator coil based on frost formation estimated based on time.

[0028] In exemplary embodiments, the controller is configured to be operable for determining whether to initiate or terminate defrost of the evaporator coil based on frost formation detection algorithmically using relative humidity, temperature, and/or openings of a space in which the evaporator coil is used.

[0029] In exemplary embodiments, the system is configured to obtain a higher evaporator temperature setpoint and/or a higher evaporator pressure setpoint by using one or more of an evaporator pressure regulator (EPR), an evaporator pressure regulating valve, or an expansion device at an inlet to an evaporator.

[0030] In exemplary embodiments, a scroll booster system is in communication with the controller that is operable for rapid changes to the evaporator temperature setpoint and/or the evaporator pressure setpoint.

[0031] In exemplary embodiments, the controller is a local case controller of a refrigerated case. Or the controller is a supervisory controller in communication with the local case controller. [0032] Also disclosed are exemplary methods for defrosting evaporator coils. In exemplary embodiments, the method comprises: monitoring the evaporator coil to determine if a defrost of the evaporator coil is required; after determining that defrost of the evaporator coil is required, initiating the defrost of the evaporator coil by: periodically changing an evaporator temperature setpoint to a value just above freezing to defrost the evaporator coil; and/or periodically changing an evaporator pressure setpoint to a value just above a pressure resulting in a temperature just above freezing to defrost the evaporator coil; and after determining that defrost of the evaporator coil is complete, terminating defrost of the evaporator coil by returning the evaporation temperature setpoint and/or the evaporator pressure setpoint to normal operation.

[0033] After determining that defrost of the evaporator coil is required, the method may include initiating the defrost of the evaporator coil by periodically changing the evaporator temperature setpoint to a value within a range from about 33 °F to about 35 °F to defrost the evaporator coil.

[0034] After determining that defrost of the evaporator coil is required, the method may include initiating the defrost of the evaporator coil by periodically changing the evaporator temperature setpoint from about -25 °F to the value within the range from about 33 °F to about 35 °F to defrost the evaporator coil; and after determining that defrost of the evaporator coil is complete, the method includes returning the evaporation temperature setpoint to about -25 °F for normal operation.

[0035] After determining that defrost of the evaporator coil is required, the method may include initiating the defrost of the evaporator coil by periodically changing the evaporator pressure setpoint to the value just above the pressure resulting in a temperature within a range from about 33 °F to about 35 °F to defrost the evaporator coil.

[0036] In exemplary embodiments, the method includes adjusting and/or optimizing a frequency at which the periodic changes to the evaporator temperature setpoint occurs and/or a frequency at which the periodic changes to the evaporator pressure setpoint occurs based on one or more condition(s) of a space in which the evaporator coil is used including one or more of a temperature of the space, a humidity of the space, and/or door opening(s) of the space. [0037] In exemplary embodiments, the method includes determining whether to initiate or terminate defrost of the evaporator coil by: using camera sensor output; and/or estimating frost formation based on time; and/or detecting frost formation algorithmically using relative humidity, temperature, and/or openings of a space in which the evaporator coil is used.

[0038] In exemplary embodiments, the method includes: obtaining a higher evaporator temperature setpoint and/or a higher evaporator pressure setpoint by using one or more of an evaporator pressure regulator (EPR), an evaporator pressure regulating valve, or an expansion device at an inlet to an evaporator; or changing the evaporator temperature setpoint and/or the evaporator pressure setpoint by using a scroll booster system.

[0039] Also disclosed are exemplary embodiments including non-transitory computer- readable storage media comprising computer-executable instructions, which when executed by at least one processor, cause a controller to be operable for: monitoring an evaporator coil to determine if a defrost of the evaporator coil is required; after determining that defrost of the evaporator coil is required, initiating the defrost of the evaporator coil by: periodically changing an evaporator temperature setpoint to a value just above freezing to defrost the evaporator coil; and/or periodically changing an evaporator pressure setpoint to a value just above a pressure resulting in a temperature just above freezing to defrost the evaporator coil; and after determining that defrost of the evaporator coil is complete, terminating defrost of the evaporator coil by returning the evaporation temperature setpoint and/or the evaporator pressure setpoint to normal operation.

[0040] In exemplary embodiments, the executable instructions include executable instructions, that when executed by the at least one processor, cause the controller to be operable for: after determining that defrost of the evaporator coil is required, initiating the defrost of the evaporator coil by periodically changing the evaporator temperature setpoint to a value within a range from about 33 °F to about 35 °F to defrost the evaporator coil. The executable instructions may include executable instructions, that when executed by the at least one processor, cause the controller to be operable for: after determining that defrost of the evaporator coil is required, initiating the defrost of the evaporator coil by periodically changing the evaporator temperature setpoint from about -25 °F to the value within the range from about 33 °F to about 35 °F to defrost the evaporator coil; and after determining that defrost of the evaporator coil is complete, returning the evaporation temperature setpoint to about -25 °F for normal operation.

[0041] In exemplary embodiments, the executable instructions include executable instructions, that when executed by the at least one processor, cause the controller to be operable for: after determining that defrost of the evaporator coil is required, initiating the defrost of the evaporator coil by periodically changing the evaporator pressure setpoint to the value just above the pressure resulting in a temperature within a range from about 33 °F to about 35 °F to defrost the evaporator coil.

[0042] In exemplary embodiments, the executable instructions include executable instructions, that when executed by the at least one processor, cause the controller to be operable for adjusting and/or optimizing a frequency at which the periodic changes to the evaporator temperature setpoint occurs and/or a frequency at which the periodic changes to the evaporator pressure setpoint occurs based on one or more condition(s) of a space in which the evaporator coil is used including one or more of a temperature of the space, a humidity of the space, and/or door opening(s) of the space.

[0043] In exemplary embodiments, the executable instructions include executable instructions, that when executed by the at least one processor, cause the controller to be operable for determining whether to initiate or terminate defrost of the evaporator coil by: using camera sensor output; and/or estimating frost formation based on time; and/or detecting frost formation algorithmically using relative humidity, temperature, and/or openings of a space in which the evaporator coil is used.

[0044] In exemplary embodiments, a controller for a defrosting system for an evaporator coil comprising the non-transitory computer-readable storage media as disclosed herein.

[0045] As will be appreciated based on the foregoing specification, the abovedescribed embodiments of the disclosure may be implemented using computer programming or engineering techniques including computer software, firmware, hardware, or any combination or subset thereof. Exemplary embodiments may include one or more processors and memory coupled to (and in communication with) the one or more processors. A processor may include one or more processing units ( e.g., in a multi-core configuration, etc.) such as, and without limitation, a central processing unit (CPU), a microcontroller, a reduced instruction set computer (RISC) processor, an application specific integrated circuit (ASIC), a programmable logic device (PLD), a gate array, and/or any other circuit or processor capable of the functions described herein.

[0046] It should be appreciated that the functions described herein, in some embodiments, may be described in computer executable instructions stored on a computer readable media, and executable by at least one processor. The computer readable media is a non-transitory computer readable storage medium. By way of example, and not limitation, such computer- readable media can include dynamic random access memory (DRAM), static random access memory (SRAM), read only memory (ROM), erasable programmable read only memory (EPROM), solid state devices, flash drives, CD-ROMs, thumb drives, floppy disks, tapes, hard disks, other optical disk storage, magnetic disk storage or other magnetic storage devices, any other type of volatile or nonvolatile physical or tangible computer-readable media, or other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Combinations of the above should also be included within the scope of computer-readable media.

[0047] Computer-executable instructions may be stored in the memory for execution by a processor to particularly cause the processor to perform one or more of the functions described herein, such that the memory is a physical, tangible, and non-transitory computer readable storage media. Such instructions often improve the efficiencies and/or performance of the processor that is performing one or more of the various operations herein. It should be appreciated that the memory may include a variety of different memories, each implemented in one or more of the functions or processes described herein.

[0048] It should also be appreciated that one or more aspects of the present disclosure transform a general -purpose computing device into a special-purpose computing device when configured to perform the functions, methods, and/or processes described herein.

[0049] Example embodiments are provided so that this disclosure will be thorough and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well- known technologies are not described in detail.

[0050] The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a”, “an” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “includes,” “including,” “has,” “have,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.

[0051] When an element or layer is referred to as being “on”, “engaged to”, “connected to” or “coupled to” another element or layer, it may be directly on, engaged, connected, or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to”, “directly connected to” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g, “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

[0052] The term “about” when applied to values indicates that the calculation or the measurement allows some slight imprecision in the value (with some approach to exactness in the value; approximately or reasonably close to the value; nearly). If, for some reason, the imprecision provided by “about” is not otherwise understood in the art with this ordinary meaning, then “about” as used herein indicates at least variations that may arise from ordinary methods of measuring or using such parameters. For example, the terms “generally”, “about”, and “substantially” may be used herein to mean within manufacturing tolerances.

[0053] Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer, or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer, or section discussed below could be termed a second element, component, region, layer, or section without departing from the teachings of the example embodiments.

[0054] Spatially relative terms, such as “inner,” “outer,” “beneath”, “below”, “lower”, “above”, “upper” and the like, may be used herein for ease of description to describe one element or feature’s relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0055] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements, intended or stated uses, or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

Claims

CLAIMS WHAT IS CLAIMED IS:

1. A system for defrosting an evaporator coil, the system comprising a controller configured to be operable for: monitoring the evaporator coil to determine if a defrost of the evaporator coil is required; after determining that defrost of the evaporator coil is required, initiating the defrost of the evaporator coil by: periodically changing an evaporator temperature setpoint to a value just above freezing to defrost the evaporator coil; and/or periodically changing an evaporator pressure setpoint to a value just above a pressure resulting in a temperature just above freezing to defrost the evaporator coil; and after determining that defrost of the evaporator coil is complete, terminating defrost of the evaporator coil by returning the evaporation temperature setpoint and/or the evaporator pressure setpoint to normal operation.

2. The system of claim 1, wherein after the controller determines that defrost of the evaporator coil is required, the controller is configured to be operable for initiating the defrost of the evaporator coil by periodically changing the evaporator temperature setpoint to a value within a range from about 33 °F to about 35 °F to defrost the evaporator coil.

3. The system of claim 2, wherein: after the controller determines that defrost of the evaporator coil is required, the controller is configured to be operable for initiating the defrost of the evaporator coil by periodically changing the evaporator temperature setpoint from about -25 °F to the value within the range from about 33 °F to about 35 °F to defrost the evaporator coil; and after determining that defrost of the evaporator coil is complete, the controller is configured to be operable for returning the evaporation temperature setpoint to about -25 °F for normal operation.

4. The system of any one of the preceding claims, wherein after the controller determines that defrost of the evaporator coil is required, the controller is configured to be operable for initiating the defrost of the evaporator coil by periodically changing the evaporator pressure setpoint to the value just above the pressure resulting in a temperature within a range from about 33 °F to about 35 °F to defrost the evaporator coil.

5. The system of any one of the preceding claims, wherein the controller is configured such that: a frequency at which the periodic changes to the evaporator temperature setpoint initially occurs is frequent; and/or a frequency at which the periodic changes to the evaporator pressure setpoint initially occurs is frequent.

6. The system of claim 5, wherein the controller is configured such that: the frequency at which the periodic changes to the evaporator temperature setpoint initially occurs is at least one per hour; and/or the frequency at which the periodic changes to the evaporator pressure setpoint initially occurs is at least once per hour.

7. The system of claim 5 or 6, wherein the controller is configured such that the frequency at which the periodic changes to the evaporator temperature setpoint and/or the frequency at which the periodic changes to the evaporator pressure setpoint is adjustable or optimizable based on one or more condition(s) of a space in which the evaporator coil is used including one or more of a temperature of the space, a humidity of the space, and/or door opening(s) of the space.

8. The system of any one of the preceding claims, wherein the controller is configured to be operable for determining whether to initiate or terminate defrost of the evaporator coil by using camera sensor output.

9. The system of any one of the preceding claims, wherein the controller is configured to be operable for determining whether to initiate or terminate defrost of the evaporator coil based on frost formation estimated based on time.

10. The system of any one of the preceding claims, wherein the controller is configured to be operable for determining whether to initiate or terminate defrost of the evaporator coil based on frost formation detection algorithmically using relative humidity, temperature, and/or openings of a space in which the evaporator coil is used.

11. The system of any one of the preceding claims, wherein the system is configured to obtain a higher evaporator temperature setpoint and/or a higher evaporator pressure setpoint by using one or more of an evaporator pressure regulator (EPR), an evaporator pressure regulating valve, or an expansion device at an inlet to an evaporator.

12. The system of any one of the preceding claims, wherein a scroll booster system is in communication with the controller that is operable for rapid changes to the evaporator temperature setpoint and/or the evaporator pressure setpoint.

13. A refrigerated case comprising the evaporator coil and the system of any one of the preceding claims, wherein: the controller is a local case controller of the refrigerated case; or the controller is a supervisory controller in communication with the local case controller.

14. A method for defrosting an evaporator coil, the method comprising: monitoring the evaporator coil to determine if a defrost of the evaporator coil is required; after determining that defrost of the evaporator coil is required, initiating the defrost of the evaporator coil by: periodically changing an evaporator temperature setpoint to a value just above freezing to defrost the evaporator coil; and/or periodically changing an evaporator pressure setpoint to a value just above a pressure resulting in a temperature just above freezing to defrost the evaporator coil; and after determining that defrost of the evaporator coil is complete, terminating defrost of the evaporator coil by returning the evaporation temperature setpoint and/or the evaporator pressure setpoint to normal operation.

15. The method of claim 14, wherein after determining that defrost of the evaporator coil is required, the method includes initiating the defrost of the evaporator coil by periodically changing the evaporator temperature setpoint to a value within a range from about 33 °F to about 35 °F to defrost the evaporator coil.

16. The method of claim 15, wherein: after determining that defrost of the evaporator coil is required, the method includes initiating the defrost of the evaporator coil by periodically changing the evaporator temperature setpoint from about -25 °F to the value within the range from about 33 °F to about 35 °F to defrost the evaporator coil; and after determining that defrost of the evaporator coil is complete, the method includes returning the evaporation temperature setpoint to about -25 °F for normal operation.

17. The method of any one of claims 14 to 16, wherein after determining that defrost of the evaporator coil is required, the method includes initiating the defrost of the evaporator coil by periodically changing the evaporator pressure setpoint to the value just above the pressure resulting in a temperature within a range from about 33 °F to about 35 °F to defrost the evaporator coil.

18. The method of any one of claims 14 to 17, wherein the method includes adjusting and/or optimizing a frequency at which the periodic changes to the evaporator temperature setpoint occurs and/or a frequency at which the periodic changes to the evaporator pressure setpoint occurs based on one or more condition(s) of a space in which the evaporator coil is used including one or more of a temperature of the space, a humidity of the space, and/or door opening(s) of the space.

19. The method of any one of claims 14 to 18, wherein the method includes determining whether to initiate or terminate defrost of the evaporator coil by: using camera sensor output; and/or estimating frost formation based on time; and/or detecting frost formation algorithmically using relative humidity, temperature, and/or openings of a space in which the evaporator coil is used.

20. The method of any one of claims 14 to 19, wherein the method includes: obtaining a higher evaporator temperature setpoint and/or a higher evaporator pressure setpoint by using one or more of an evaporator pressure regulator (EPR), an evaporator pressure regulating valve, or an expansion device at an inlet to an evaporator; or changing the evaporator temperature setpoint and/or the evaporator pressure setpoint by using a scroll booster system.

21. A non-transitory computer-readable storage media comprising computerexecutable instructions, which when executed by at least one processor, cause a controller to be operable for: monitoring an evaporator coil to determine if a defrost of the evaporator coil is required; after determining that defrost of the evaporator coil is required, initiating the defrost of the evaporator coil by: periodically changing an evaporator temperature setpoint to a value just above freezing to defrost the evaporator coil; and/or periodically changing an evaporator pressure setpoint to a value just above a pressure resulting in a temperature just above freezing to defrost the evaporator coil; and after determining that defrost of the evaporator coil is complete, terminating defrost of the evaporator coil by returning the evaporation temperature setpoint and/or the evaporator pressure setpoint to normal operation.

22. The non-transitory computer-readable storage media of claim 21, wherein the executable instructions include executable instructions, that when executed by the at least one processor, cause the controller to be operable for: after determining that defrost of the evaporator coil is required, initiating the defrost of the evaporator coil by periodically changing the evaporator temperature setpoint to a value within a range from about 33 °F to about 35 °F to defrost the evaporator coil.

23. The non-transitory computer-readable storage media of claim 22 or 23, wherein the executable instructions include executable instructions, that when executed by the at least one processor, cause the controller to be operable for: after determining that defrost of the evaporator coil is required, initiating the defrost of the evaporator coil by periodically changing the evaporator temperature setpoint from about -25 °F to the value within the range from about 33 °F to about 35 °F to defrost the evaporator coil; and after determining that defrost of the evaporator coil is complete, returning the evaporation temperature setpoint to about -25 °F for normal operation.

24. The non-transitory computer-readable storage media of any one of claims 21 to 23, wherein the executable instructions include executable instructions, that when executed by the at least one processor, cause the controller to be operable for: after determining that defrost of the evaporator coil is required, initiating the defrost of the evaporator coil by periodically changing the evaporator pressure setpoint to the value just above the pressure resulting in a temperature within a range from about 33 °F to about 35 °F to defrost the evaporator coil.

25. The non-transitory computer-readable storage media of any one of claims 21 to 24, wherein the executable instructions include executable instructions, that when executed by the at least one processor, cause the controller to be operable for adjusting and/or optimizing a frequency at which the periodic changes to the evaporator temperature setpoint occurs and/or a frequency at which the periodic changes to the evaporator pressure setpoint occurs based on one or more condition(s) of a space in which the evaporator coil is used including one or more of a temperature of the space, a humidity of the space, and/or door opening(s) of the space.

26. The non-transitory computer-readable storage media of any one of claims 21 to 25, wherein the executable instructions include executable instructions, that when executed by the at least one processor, cause the controller to be operable for determining whether to initiate or terminate defrost of the evaporator coil by: using camera sensor output; and/or estimating frost formation based on time; and/or detecting frost formation algorithmically using relative humidity, temperature, and/or openings of a space in which the evaporator coil is used.

27. A controller for a defrosting system for an evaporator coil, the controller comprising the non-transitory computer-readable storage media of any one of claims 21 to 26.