Patent Publication Number: US-2020289693-A1

Title: System and method for detecting and removing odor and bacteria from a sealed volume of an appliance using ozone

Description:
FIELD OF THE INVENTION 
     The subject matter of the present disclosure relates generally to a system and method for detecting and removing odor and bacteria from a sealable volume of an appliance using ozone. 
     BACKGROUND OF THE INVENTION 
     Odor and bacteria within a sealed volume of an appliance can be unpleasant to consumers. Many different types of appliances include sealed volumes in which bacteria can grow and odor can emanate if left unaddressed. For instance, refrigerator appliances can include one or chilled chambers for storing food items. Storing food items for too long can cause mold and bacteria, including Psychrophilic bacteria, which can survive in a cold environment. To remove odors from the chilled chambers, consumers are typically directed to use baking soda. While odors can be removed by the baking soda technique, this technique is not able to remove any bacteria from the chilled chambers. Thus, the odors will likely return. Further, washing machines and dryers also include sealable volumes. To remove odors/bacteria therefrom, consumers are typically directed to run a full wash cycle or drying cycle. Running a full cycle to remove odor/bacteria can require significant time &amp; energy. Dishwashers, air conditioners, and microwaves/ovens can also include sealable volumes. Dishwashers typically do not include odor removal systems, and in some instances, foul smelling odors can be absorbed by the gaskets and plastic components thereof. For air conditioners, evaporators can smell bad if not operated for a while and moisture is not fully removed. For microwaves or ovens, constantly heating various types of food items can generator odor into various parts of the microwave/oven (fan, rotation plate, etc.). 
     Ozone can be an effective sterilant and oxidizer for removing odors, bacteria, and viruses in a sealable volume. Ozone generators can be used to inject ozone into a sealable volume. However, there are currently no satisfactory systems or methods to ensure that the amount of ozone within the sealable volume does not exceed unsafe levels. Exposure of ozone must be avoided by consumers as high concentration levels of ozone may harm consumers&#39; respiratory systems. Accordingly, when ozone is used to deodorize or remove bacteria from a sealable volume, consumers are instructed to leave the area and to return only after the ozone is reverted to oxygen. This can be an inconvenience to users and current systems can be ineffective in actually removing the odor/bacteria from the sealed volume. Furthermore, in some instances, conventional systems can inject too little ozone into the sealed volume. In such instances, the ozone injection is ineffective in removal of bacteria/odor from the sealed volume. 
     Accordingly, a system and method that address one or more of the challenges noted above would be useful. 
     BRIEF DESCRIPTION OF THE INVENTION 
     Aspects and advantages of the invention will be set forth in part in the following description, or may be apparent from the description, or may be learned through practice of the invention. 
     In one aspect, an appliance is provided. The appliance includes a housing defining a sealable volume. The appliance also includes an ozone generator operable to dispense ozone into the sealable volume. Further, the appliance includes an ozone detection device operable to detect a concentration level of ozone within the sealable volume. In addition, the appliance includes a controller communicatively coupled with the ozone generator and the ozone detection device. The controller is configured to: i) cause, at a predetermined injection interval, the ozone generator to inject a predefined dosage of ozone into the sealable volume; ii) receive, from the ozone detection device, an input indicative of the concentration level of ozone within the sealable volume; iii) determine the concentration level of ozone within the sealable volume based at least in part on the received input; and iv) ascertain whether the determined concentration level has reached a maximum concentration level threshold. Further, the controller iteratively i) causes, ii) receives, iii) determines, and iv) ascertains until the determined concentration level reaches the maximum concentration level threshold or a maximum generator on time has elapsed. 
     In another aspect, a method for operating an appliance in an odor removal cycle is provided. The method includes injecting, at a predetermined injection interval, a predefined dosage of ozone into a sealable volume of the appliance. Further, the method includes measuring, after each injection of the predefined dosage of ozone into the sealable volume of the appliance, a concentration level of ozone within the sealable volume. In addition, the method includes ascertaining whether the concentration level has reached a maximum concentration level threshold, and wherein if the concentration level has reached the maximum concentration level threshold, then no further injections of the predefined dosage of ozone are made. 
     These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which: 
         FIG. 1  provides a perspective view of a refrigerator appliance according to example embodiments of the present subject matter; 
         FIG. 2  provides a perspective view of the refrigerator appliance of  FIG. 1 , wherein refrigerator doors of the refrigerator appliance are depicted in an open position to reveal a fresh food chamber of the refrigerator appliance; 
         FIG. 3  provides a schematic view of an example appliance equipped with an ozone monitoring system according to example embodiments of the present subject matter; 
         FIG. 4  provides a flow diagram of a method for operating an appliance in an odor removal cycle according to example embodiments of the present subject matter; and 
         FIGS. 5, 6, and 7  provide graphs depicting a concentration level of ozone as a function of time for three different scenarios according to example embodiments of the present subject matter. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents. As used herein, terms of approximation, such as “approximately,” “substantially,” or “about,” refer to being within a fifteen percent (15%) margin of error. 
       FIGS. 1 and 2  provide various views of a refrigerator appliance  100  according to example embodiments of the present subject matter. Particularly,  FIG. 1  provides a perspective view of refrigerator appliance  100  and  FIG. 2  provides a perspective view of refrigerator appliance  100  having multiple refrigerator doors  128  in the open position. As shown, refrigerator appliance  100  includes a cabinet or cabinet  120  that extends between a top  101  and a bottom  102  along a vertical direction V. Cabinet  120  also extends along a lateral direction L and a transverse direction T, each of the vertical direction V, lateral direction L, and transverse direction T being mutually perpendicular to one another. In turn, vertical direction V, lateral direction L, and transverse direction T define an orthogonal direction system. 
     Cabinet  120  includes a liner  121  that defines one or more sealable volumes. For this embodiment, the sealable volumes are chilled chambers configured for receipt of food items for storage. In particular, liner  121  defines a fresh food chamber  122  positioned at or adjacent top  101  of cabinet  120  and a freezer chamber  124  arranged at or adjacent bottom  102  of cabinet  120 . As such, refrigerator appliance  100  is generally referred to as a bottom mount refrigerator. It is recognized, however, that the benefits of the present disclosure apply to other types and styles of appliances such as, e.g., a top mount refrigerator appliance, a side-by-side style refrigerator appliance, or a range appliance. Further, as will be explained herein, the benefits of the present disclosure apply to other types of appliances as well. Consequently, the description set forth herein is for illustrative purposes only and is not intended to be limiting in any aspect to any particular refrigerator chamber configuration. 
     Refrigerator doors  128  are rotatably hinged to an edge of cabinet  120  for selectively accessing fresh food chamber  122 . In addition, a freezer door  130  is arranged below refrigerator doors  128  for selectively accessing freezer chamber  124 . Freezer door  130  is attached to a freezer drawer (not shown) slidably mounted within freezer chamber  124 . Refrigerator doors  128  and freezer door  130  are shown in the closed configuration in  FIG. 1 . 
     In some embodiments, refrigerator appliance  100  also includes a dispensing assembly  140  for dispensing liquid water and/or ice. Dispensing assembly  140  includes a dispenser  142  positioned on or mounted to an exterior portion of refrigerator appliance  100 , e.g., on one of refrigerator doors  128 . Dispenser  142  includes a discharging outlet  144  for accessing ice and liquid water. An actuating mechanism  146 , shown as a paddle, is mounted below discharging outlet  144  for operating dispenser  142 . In alternative exemplary embodiments, any suitable actuating mechanism may be used to operate dispenser  142 . For example, dispenser  142  can include a sensor (such as an ultrasonic sensor) or a button rather than the paddle. A user interface panel  148  is provided for controlling the mode of operation. For example, user interface panel  148  includes a plurality of user inputs (not labeled), such as a water dispensing button and an ice-dispensing button (e.g., for selecting a desired mode of operation such as crushed or non-crushed ice). 
     Discharging outlet  144  and actuating mechanism  146  are an external part of dispenser  142  and are mounted in a dispenser recess  150 . Dispenser recess  150  is positioned at a predetermined elevation convenient for a user to access ice or water and enabling the user to access ice without the need to bend-over and without the need to open refrigerator doors  128 . 
     According to the illustrated embodiment, various storage components are mounted within fresh food chamber  122  to facilitate storage of food items therein as will be understood by those skilled in the art. In particular, the storage components include storage bins  166 , drawers  168 , and shelves  170  that are mounted within fresh food chamber  122 . Storage bins  166 , drawers  168 , and shelves  170  are configured for receipt of food items (e.g., beverages and/or solid food items) and may assist with organizing such food items. As an example, drawers  168  can receive fresh food items (e.g., vegetables, fruits, and/or cheeses) and increase the useful life of such fresh food items. 
     Operation of the refrigerator appliance  100  can be controlled or regulated by a controller  190 . As will be described in detail below, controller  190  may include multiple modes of operation or sequences that control or regulate various portions of refrigerator appliance  100  according to one or more discrete criteria. 
     In some embodiments, controller  190  is operably coupled to user interface panel  148  and/or various other components, as will be described below. User interface panel  148  provides selections for user manipulation of the operation of refrigerator appliance  100 . As an example, user interface panel  148  may provide for selections between whole or crushed ice, chilled water, and/or specific modes of operation. In response to one or more input signals (e.g., from user manipulation of user interface panel  148  and/or one or more sensor signals), controller  190  may operate various components of the refrigerator appliance  100 . 
     Controller  190  may include a memory and one or more microprocessors, CPUs or the like, such as general or special purpose microprocessors operable to execute programming instructions or micro-control code associated with operation of refrigerator appliance  100 . The memory may represent random access memory such as DRAM, or read only memory such as ROM or FLASH. In some embodiments, the processor executes non-transitory programming instructions stored in memory. For certain embodiments, the instructions include a software package configured to operate appliance  100  and, e.g., execute an operation routine including the example method ( 300 ) described below with reference to  FIG. 4 . The memory may be a separate component from the processor or may be included onboard within the processor. Alternatively, controller  190  may be constructed without using a microprocessor, e.g., using a combination of discrete analog and/or digital logic circuitry (such as switches, amplifiers, integrators, comparators, flip-flops, AND gates, and the like) to perform control functionality instead of relying upon software. 
     Controller  190 , or portions thereof, may be positioned in a variety of locations throughout refrigerator appliance  100 . In example embodiments, controller  190  is located within the user interface panel  148  as shown in  FIG. 1 . In other embodiments, the controller  190  may be positioned at any suitable location within refrigerator appliance  100 , such as for example within a fresh food chamber, a freezer door, etc. In additional or alternative embodiments, controller  190  is formed from multiple components mounted at discrete locations within or on refrigerator appliance  100 . Input/output (“I/O”) signals may be routed between controller  190  and various operational components of refrigerator appliance  100 . For example, user interface panel  148  may be operably coupled (e.g., directly or indirectly electrically coupled) to controller  190  via one or more signal lines or shared communication busses. 
     In addition, as shown in  FIG. 2 , refrigerator appliance  100  can include an ozone monitoring system, as represented by  195 . Ozone monitoring system  195  is operable to detect odor/bacteria/viruses in a sealed (or air tight) area of refrigerator appliance  100 , such as e.g., fresh food chamber  122  and/or freezer chamber  124 . Various components of ozone monitoring system  195  can be communicatively coupled with and controlled by controller  190 . An example monitoring system for an appliance is provided below. 
       FIG. 3  provides a schematic view of an example appliance  200  equipped with an ozone monitoring system  230  according to example embodiments of the present subject matter. For instance, appliance  200  of  FIG. 3  can be the refrigerator appliance  100  of  FIGS. 1 and 2  and ozone monitoring system  230  can be ozone monitoring system  195  depicted in  FIG. 2 . However, the appliance  200  of  FIG. 3  can be any suitable appliance having a sealable volume and the ozone monitoring features described below. By way of example, without limitation, appliance  200  of  FIG. 3  can be a washing machine appliance, a dryer appliance, a microwave appliance, an oven appliance, or an air conditioner appliance. In addition, compliance  200  of  FIG. 3  can be a refrigerator appliance having a different configuration than refrigerator appliance  100  of  FIGS. 1 and 2 . 
     As depicted in  FIG. 3 , appliance  200  includes a housing  210  defining a sealable volume  212 . For example, the housing  210  can be cabinet  120  of refrigerator appliance  100  and sealable volume  212  can be one of the chilled chambers  122 ,  124  thereof. A door  214  is operatively coupled with housing  210  for providing selective access to the sealable volume  212 . Door  214  is movable between a closed position in which sealable volume  212  is sealed and an open position. In some embodiments, in the closed position, door  214  hermetically seals sealable volume  212  such that sealable volume  212  is a sealed volume. In the open position, door  214  does not hermetically seal sealable volume  212 ; thus, when door  214  is in the open position, sealable volume  212  is not sealed. For this embodiment, door  214  includes a door lock  216  for selectively locking door  214 , e.g., in the closed position. As will be explained herein, during an odor removal cycle, a controller  220  of appliance  200  can cause door lock  216  to keep or maintain door  214  in the closed position, e.g., until completion of the cycle. 
     Appliance  200  also includes ozone monitoring system  230 . Generally, ozone monitoring system  230  is operable to remove bacteria and odor from sealable volume  212  in a safe and efficient manner. Ozone monitoring system  230  includes an ozone generator  232  operable to dispense or inject ozone into the sealable volume  212 . For instance, ozone generator  232  is depicted in  FIG. 3  injecting ozone O 3  into sealable volume  212 . If odor, bacteria, and/or viruses are present within sealable volume  212 , the ozone O 3  injected therein can be “consumed” or reverted to oxygen molecules after destroying odor, bacteria, and/or viruses. Ozone O 3  is one suitable sterilant and oxidizer effective in destroying odor, bacteria and viruses in sealable volume  212 . In some alternative embodiments, generator device  232  can generate another sterilant/oxidizer, such as e.g., a suitable variant of ozone O 3 . 
     Ozone monitoring system  230  also includes an ozone detection device  234 . Ozone detection device  234  can be any suitable sensor operable to sense or detect the ozone concentration within sealable volume  212 . For instance, after ozone generator  232  injects a predefined dosage of ozone into sealable volume  212 , ozone detection device  234  can sense the ozone concentration within sealable volume  212 . One or more signals indicative of the concentration level of ozone within sealable volume  212  can be routed from ozone detection device  234  to controller  220  for processing, which as shown in  FIG. 3 , is communicatively coupled thereto. 
     In some example embodiments, optionally, ozone monitoring system  230  includes an air handler  236  (e.g., a fan). Air handler  236  is operable to facilitate diffusion of ozone O 3  within sealable volume  212 . For instance, prior to, simultaneously with, or after ozone generator  232  injects ozone O 3  into sealable volume  212 , controller  220  can activate air handler  236  to move air about sealable volume  212 . Consequently, air handler  236  assists with mixing of ozone O 3  with the existing air within sealable volume  212 . This can, for example, cause more rapid diffusion of ozone O 3  with the existing air within sealable volume  212 . Controller  220  can also deactivate air handler  236 , e.g., at the end of the odor removal cycle. 
     Further, in some example embodiments, optionally, ozone monitoring system  230  includes an ozone destructor device  238 . Ozone destructor device  238  is operable to reduce the concentration level of ozone within the sealable volume  212 . For instance, ozone O 3  within sealable volume  212  can be destructed by ozone destructor device  238  via a catalyst, such as e.g., manganese dioxide MnO 2 . Ozone destructor device  238  can destruct ozone O 3  within sealable volume  212  at any suitable time. For instance, as will be explained in detail herein, controller  220  can cause ozone destructor device  238  to destruct or reduce the concentration level of ozone O 3  when the ozone concentration level within sealable volume  212  reaches a threshold. In addition, in some embodiments, ozone destructor device  238  can impart heat into the sealable volume  212 . In this way, ozone O 3  within sealable volume  212  can be destructed. 
     Controller  220  of appliance  200  is also a component of system  230 . In some embodiments, controller  220  of system  230  can be dedicated solely to performing operations for operating appliance  200  in an odor removal cycle. In yet other embodiments, in addition to performing operations for operating appliance  200  in an odor removal cycle, controller  220  can perform other operations associated with appliance  200 . Controller  220  can be configured the same or similar to the controller  190  of refrigerator appliance  100  of  FIGS. 1 and 2 . Particularly, controller  220  can include one or more memory devices and one or more processing devices. For instance, the processing devices can be microprocessors, CPUs, or the like, such as general or special purpose microprocessors operable to execute programming instructions or micro-control code associated with operations of appliance  200 . The memory devices can include random access memory such as DRAM, and/or read only memory such as ROM or FLASH. In some embodiments, the one or more processing devices execute non-transitory programming instructions stored in the one or more memory devices. For certain embodiments, the instructions include a software package configured to operate appliance  200 , e.g., in an odor removal cycle. The one or memory devices can be separate components from the one or more processors or may be included onboard with the processors. Alternatively, controller  220  can be constructed without using a microprocessor, e.g., using a combination of discrete analog and/or digital logic circuitry (such as switches, amplifiers, integrators, comparators, flip-flops, AND gates, and the like) to perform control functionality instead of relying upon software. 
     Controller  220  can send and receive signals from various components of appliance  200 , and particularly, components of ozone monitoring system  230 . As depicted in  FIG. 3 , controller  220  is communicatively coupled with ozone generator  232 , ozone detection device  234 , air handler  236 , ozone destructor device  238 , and door lock  216 . Controller  220  can also be communicatively coupled with other components of appliance  200  as well. Controller  220  can be communicatively coupled with these various devices in any suitable manner, e.g., a suitable wired or wireless communication link. Controller  220  can control appliance  200  in an odor removal cycle in a manner described below as set forth in method ( 300 ). 
       FIG. 4  provides a flow diagram of a method ( 300 ) for operating an appliance in an odor removal cycle according to example embodiments of the present subject matter. For instance, the method ( 300 ) can be implemented to operate appliance  200  of  FIG. 3  in an odor removal cycle. Appliance  200  can be any suitable type of appliance, including, without limitation, a refrigerator appliance, a washing machine appliance, a dryer appliance, a microwave appliance, an oven appliance, or an air conditioner appliance. Reference numerals used to denote certain features of appliance  200  of  FIG. 3  will be utilized below to provide context to method ( 300 ). In addition, it will be appreciated that method ( 300 ) can be modified, adapted, expanded, rearranged and/or omitted in various ways without deviating from the scope of the present subject matter. 
     At ( 302 ), the method ( 300 ) includes commencing an odor removal cycle. The odor removal cycle can be commenced in a number of suitable ways. For instance, a user can manually commence the odor removal cycle. For example, a user can manipulate one or more controls of the user interface of appliance  200 . As another example, a user can start the odor removal cycle by utilizing an application on a remote user device communicatively coupled with controller  220  of appliance  200 . Another suitable manner for commencing the odor removal cycle can include commencing the odor removal cycle at a predetermined interval, such as e.g., every week, every month, etc. In this manner, the odor removal cycle can be performed without user interaction with appliance  200 . 
     At ( 304 ), the method ( 300 ) includes injecting, at a predetermined interval, a predefined dosage of ozone into a sealable volume of an appliance. For instance, with reference to  FIG. 3 , controller  220  can cause ozone generator  232  to inject a predefined dosage of ozone O 3  into sealable volume  212 . The predefined dosage of ozone can be a known volume of ozone O 3 . Accordingly, when a predefined dosage of ozone O 3  is injected into sealable volume  212 , controller  220  can track the amount or volume of ozone O 3  dispensed or injected into sealable volume  212 . As will be explained in further detail below, controller  220  can iteratively cause ozone generator  232  to inject a predefined dosage of ozone O 3  into sealable volume  212  at a predefined time interval. The predetermined time interval can be set based at least in part on the dosage amount and the volume of the sealable volume  212 , among other possible criteria. 
     At ( 306 ), optionally, the method ( 300 ) includes activating an air handler to facilitate diffusion of the ozone within the sealable volume. For instance, the air handler can be air handler  236  of  FIG. 4 . Prior to, simultaneously with, or after ozone generator  232  injects ozone O 3  into sealable volume  212  at ( 304 ), controller  220  can activate air handler  236  to move air about sealable volume  212 . As a result, injected ozone O 3  can be more rapidly mixed with the existing air within sealable volume  212 . As noted previously, this can cause more rapid diffusion of ozone O 3  with the existing air within sealable volume  212 . Air handler  236  can be activated with each injected dosage and can run for a predetermined time, can be activated after the first dosage and can run for the entire odor removal cycle, or can be activated until the occurrence of some event, such as e.g., when the concentration level of ozone O 3  within sealable volume  212  reaches a maximum concentration level threshold, among other possibilities. 
     At ( 308 ), the method ( 300 ) includes measuring a concentration level of ozone within the sealable volume after each injection of the predefined dosage of ozone into the sealable volume of the appliance. In some implementations, measuring the concentration level of ozone within the sealable volume includes receiving, from an ozone detection device, an input indicative of the concentration level of ozone within the sealable volume and then determining the concentration level of ozone within the sealable volume based at least in part on the received input. 
     For instance, with reference to  FIG. 3 , controller  220  can receive, from ozone detection device  234 , an input indicative of a concentration level of ozone O 3  within the sealable volume  212 . For example, controller  220  can receive one or more electrical signals indicative of the concentration level ozone O 3  within the sealable volume  212 . Controller  220  can receive such signals, or the input, and can determine the concentration level of ozone O 3  within sealable volume  212  based at least in part on the received input. Controller  220  can determine the concentration level of ozone O 3  within sealable volume  212  in any suitable units, such as e.g., parts per million (ppm). Controller  220  can measure or determine the concentration level of ozone O 3  within sealable volume  212  at a predetermined diffusion time after each predefined dosage of ozone O 3 . For instance, controller  220  can measure the concentration level of ozone O 3  within sealable volume  212  twenty (20) seconds (i.e., the predetermined diffusion time) after each predefined dosage of ozone O 3  is injected into sealable volume  212 . 
     At ( 310 ), the method ( 300 ) includes ascertaining whether the concentration level has reached a maximum concentration level threshold. If the concentration level has reached the maximum concentration level threshold, then no further injections of the predefined dosage of ozone are made. For instance, referring to  FIG. 3 , controller  220  can ascertain whether the determined concentration level has reached the maximum concentration level threshold. Notably, controller  220  iteratively i) causes ozone generator  232  to inject a predefined dosage of ozone O 3  into sealable volume  212 , ii) receives an input indicative of a concentration level of ozone O 3  within the sealable volume  212 , iii) determines the concentration level of ozone O 3  within sealable volume  212  based at least in part on the received input, and iv) ascertains whether the concentration level has reached a maximum concentration level threshold at a predetermined time interval until the determined concentration level reaches the maximum concentration level threshold as determined at ( 310 ) or a maximum generator on time has elapsed as determined at ( 312 ). 
     At ( 312 ), if the concentration level has not reached the maximum concentration level threshold T MAX , then the method ( 300 ) includes determining whether a maximum generator on time has elapsed. For instance, controller  220  can maintain a timer or clock. The timer can be started when the first ozone dosage is injected into sealable volume  212  at ( 304 ) and can terminate at the end of the maximum generator on time. In this way, ozone generator  232  is prevented from running indefinitely in the event of a failure condition. If the maximum generator on time has not elapsed as determined at ( 312 ), then method ( 300 ) reverts to ( 304 ) so that another predefined dosage of ozone can be injected into sealable volume  212  by ozone generator  232 . If, however, the maximum generator on time has elapsed as determined at ( 312 ), then the method ( 300 ) proceeds to ( 322 ) where controller  220  determines that a fault condition is detected and can set a flag indicating the fault detected. 
       FIGS. 5, 6, and 7  present three (3) example scenarios in which method ( 300 ) may proceed through ( 304 ) through ( 312 ). Particularly,  FIGS. 5, 6, and 7  provide graphs depicting a concentration level of ozone as a function of time for three different scenarios according to example embodiments of the present subject matter. 
     With reference to  FIG. 5 , in a first scenario, there may be negligible or no odor, bacteria, viruses, and/or other contaminants to remove from sealable volume  212 . In such instances, injected ozone O 3  will not be “consumed,” and thus the concentration level of ozone O 3  will accumulate with each injected predefined dosage of ozone O 3 . By way of example, as shown in  FIG. 5 , a number of ozone dosages are injected into sealable volume  212 , including a first dosage D 1 , a second dosage D 2 , a third dosage D 3 , a fourth dosage D 4 , and a fifth dosage D 5 . The ozone dosages D 1 , D 2 , D 3 , D 4 , D 5  are injected at a predetermined injection interval, as represented by I. 
     Notably, after the first dosage D 1  of ozone O 3  is injected at ( 304 ) of method ( 300 ), the concentration level of ozone O 3  remains relatively constant for a time (e.g., until the second dosage D 2  is injected). This represents that the injected ozone O 3  is not being “consumed” or reacting with odors, bacteria, viruses, and/or other contaminants within sealable volume  212 . After the first dosage D 1 , controller  220  measures the concentration level of ozone O 3  within the sealable volume  212  at ( 308 ) of method ( 300 ), (e.g., controller  220  receives an input indicative of the concentration level from ozone detection device  234  and determines the concentration level based at least in part on the received input), and ascertains at ( 310 ) that the concentration level has not reached the maximum concentration level threshold T MAX . Accordingly, the method ( 300 ) reverts to ( 304 ) if the maximum generator on time has not elapsed as determined at ( 312 ). 
     If the concentration level has not reached the maximum concentration level threshold T MAX  and the maximum generator on time has not elapsed, then at ( 304 ) controller  220  once again causes ozone generator  232  to inject a predefined dosage of ozone into sealable volume  212 . For instance, as shown in  FIG. 5 , the second dosage D 2  is injected by ozone generator  232 . After the second dosage D 2  of ozone O 3  is injected at ( 304 ), the concentration level of ozone O 3  remains relatively constant for a time (e.g., until the third dosage D 3  is injected). This represents that the injected ozone O 3  is still not being “consumed” or reacting with odors, bacteria, viruses, and/or other contaminants within sealable volume  212 . After the second dosage D 2 , controller  220  measures the concentration level of ozone O 3  within the sealable volume  212  at ( 308 ) of method ( 300 ), and ascertains at ( 310 ) that the concentration level has not reached the maximum concentration level threshold T MAX , e.g., as shown in  FIG. 5 . Accordingly, the method ( 300 ) reverts to ( 304 ) if the maximum generator on time has not elapsed as determined at ( 312 ). This process continues until the determined concentration level reaches the maximum concentration level threshold T MAX  (e.g., at time t X  as shown in  FIG. 5 ) or if the maximum generator on time has elapsed. If either of these conditions are met, then controller  220  ceases causing ozone generator  232  to inject ozone into sealable volume  212 . 
     With reference to  FIG. 6 , in a second scenario, odor, bacteria, viruses, and/or some other contaminants exist in sealable volume  212  and can be removed with ozone O 3 . By way of example, as shown in  FIG. 6 , a number of ozone dosages are injected into sealable volume  212 , including a first dosage D 1 , a second dosage D 2 , a third dosage D 3 , a fourth dosage D 4 , and fifth dosage D 5 , a sixth dosage D 6 , a seventh dosage D 7 , and an eighth dosage D 8 . The ozone dosages D 1 , D 2 , D 3 , D 4 , D 5 , D 6 , D 7 , D 8  are injected at a predetermined injection interval, as represented by I. The degree of odor/bacteria is measured based on the amount of time it takes to remove all odor/bacteria. If the ozone concentration level is increasing, it is an indication that all odor/bacteria is removed. 
     After the first dosage D 1  of ozone O 3  is injected into sealable volume  212  at ( 304 ), the concentration level of ozone O 3  decreases (e.g., until the second dosage D 2  is injected). This represents that the injected ozone O 3  is being “consumed” or reacting with odors, bacteria, viruses, and/or other contaminants within sealable volume  212 . After the first dosage D 1 , controller  220  measures the concentration level of ozone O 3  within the sealable volume  212  at ( 308 ) of method ( 300 ), and ascertains at ( 310 ) that the concentration level has not reached the maximum concentration level threshold T MAX . Accordingly, the method ( 300 ) reverts to ( 304 ) if the maximum generator on time has not elapsed as determined at ( 312 ). This process continues until the determined concentration level reaches the maximum concentration level threshold T MAX  as determined at ( 310 ) or if the maximum generator on time has elapsed as determined at ( 312 ). 
     After the method ( 300 ) loops through ( 304 ) through ( 312 ) for second and third dosages D 2  and D 3 , after the fourth dosage D 4  of ozone O 3  is injected at ( 304 ) of method ( 300 ), the concentration level of ozone O 3  remains relatively constant for a time (e.g., until the fifth dosage D 5  is injected). This represents that the injected ozone O 3  is no longer being “consumed” or reacting with odors, bacteria, viruses, and/or other contaminants within sealable volume  212 . With no further odors, bacteria, viruses, and/or other contaminants within sealable volume  212  for ozone O 3  to react with, the concentration level continues to increase in a stepwise function for dosages D 5 , D 6 , D 7 , and D 8  until the concentration level of ozone O 3  reaches the maximum concentration level threshold T MAX  (e.g., at time t X  as shown in  FIG. 6 ). 
     With reference to  FIG. 7 , in a third scenario, dosages of ozone O 3  are injected into sealable volume  212  at a predetermined injection interval I, yet the concentration level of ozone O 3  does not reach the maximum concentration level threshold T MAX  as determined at ( 310 ) before the maximum generator on time has elapsed as determined at ( 312 ). By way of example, as shown in  FIG. 7 , a number of ozone dosages are injected into sealable volume  212 , including a first dosage D 1 , a second dosage D 2 , a third dosage D 3 , a fourth dosage D 4 , and fifth dosage D 5 , a sixth dosage D 6 , a seventh dosage D 7 , an eighth dosage D 8 , and a ninth dosage D 9 . The ozone dosages D 1 , D 2 , D 3 , D 4 , D 5 , D 6 , D 7 , D 8 , D 9  are injected at the predetermined injection interval I, as noted above. 
     As shown, after each dosage of ozone O 3  injected into sealable volume  212  by ozone generator  232 , the concentration level decreases (e.g., until a subsequent dosage is injected). This represents that the injected ozone O 3  is being “consumed” or reacting with odors, bacteria, viruses, and/or other contaminants within sealable volume  212 . Thus, method ( 300 ) continues within the ( 304 ) to ( 312 ) loop until the determined concentration level reaches the maximum concentration level threshold T MAX  as determined at ( 310 ) or if the maximum generator on time has elapsed as determined at ( 312 ). In the third scenario shown in  FIG. 7 , the determined concentration level does not reach the maximum concentration level threshold T MAX  before the maximum generator on time elapses. Thus, as shown in  FIG. 4 , the method ( 300 ) proceeds to ( 322 ). 
     At ( 314 ), in some implementations, the method ( 300 ) includes activating one or more ozone removal devices. For instance, in some implementations, activating the one or more ozone removal devices includes activating ozone destructor device  238  to reduce the concentration level of ozone O 3  within sealable volume  212 . For instance, if the determined concentration level reaches the maximum concentration level threshold T MAX  as determined at ( 310 ), controller  220  is configured to activate ozone destructor device  238  to reduce the concentration level of ozone within sealable volume  212 . For instance, ozone destructor device  238  can reduce the concentration level of ozone O 3  within sealable volume  212  via a catalyst, such as e.g., manganese dioxide MnO 2 . Ozone destructor device  238  can destruct ozone O 3  within sealable volume  212  when the ozone concentration level within sealable volume  212  reaches the maximum concentration level threshold T MAX , e.g., as shown in  FIG. 5  after the fifth dosage D 5  and in  FIG. 6  after the eighth dosage D 8 . In yet other implementations of method ( 300 ), the ozone destructor device  238  can reduce the concentration level of ozone O 3  within sealable volume  212  by imparting heat to sealable volume  212 . 
     In some implementations, activating the one or more ozone removal devices at ( 314 ) includes causing a damper to move to an open position such that ozone can be exhausted from sealable volume. In such implementations, when the damper is moved to the open position, the ozone O 3  within sealable volume  212  can be passively exhausted out of sealable volume  212 . In such implementations, ozone destructor device  238  can, but need not, be activated at ( 314 ). For instance, as shown in  FIG. 3 , appliance  200  includes a venting conduit  240  that fluidly connects sealable volume  212  with a second volume, such as e.g., an ambient environment  244  or some other volume (e.g., another sealable volume of the appliance  200 ). A damper  242  movable between an open position and a closed position is positioned along venting conduit  240 . When damper  242  is in the open position, fluid (e.g., air) is permitted to flow through venting conduit  240  (e.g., from sealable volume  212  to ambient environment  244 ). When damper  242  is in the closed position, fluid is prevented from flowing through venting conduit  240 . Thus, when damper  242  is in the closed position, sealable volume  212  is in fact sealed. 
     Further, in some implementations, ozone O 3  can be forced or actively exhausted from sealable volume  212  through venting conduit  240 . In such implementations, activating the one or more ozone removal devices at ( 314 ) includes activating an air handler. For instance, in such implementations, controller  220  can activate air handler  236  when damper  242  is moved the open position, e.g., to more rapidly move ozone O 3  from sealable volume  212 . Controller  220  can activate air handler  236  and cause damper  242  to move to the open position simultaneously. Alternatively, the timing can be offset. 
     At ( 316 ), the method ( 300 ) includes once again measuring the concentration level of ozone within the sealable volume of the appliance. In some implementations, measuring the concentration level of ozone within the sealable volume includes receiving from a detection device, an input (e.g., a second input) indicative of the concentration level of ozone within the sealable volume and determining the concentration level of ozone within the sealable volume based at least in part on the received input (e.g., the received second input). 
     For instance, after controller  220  determines that the concentration level has reached the maximum concentration level threshold T MAX  at ( 310 ), controller  220  can receive, from ozone detection device  234 , a second input indicative of a concentration level of ozone O 3  within the sealable volume  212 . For example, controller  220  can receive one or more electrical signals indicative of the concentration level ozone O 3  within the sealable volume  212 . Controller  220  can receive such signals, or the second input, and can determine the concentration level of ozone O 3  within sealable volume  212  based at least in part on the received second input. Accordingly, controller  220  measures the concentration level of ozone O 3  within sealable volume  212  of appliance  200  in much the same as done at ( 308 ). 
     At ( 318 ), the method ( 300 ) includes ascertaining whether the determined concentration level has reached a minimum concentration level threshold. For instance, based on the concentration level of ozone O 3  within sealable volume  212  determined at ( 314 ), controller  220  ascertains whether the determined concentration level has reached a minimum concentration level threshold T MIN . The minimum concentration level threshold T MIN  can be set such that the concentration level is associated with a safe level for humans. For instance, the minimum concentration level threshold T MIN  can be set at a level that corresponds with an ozone concentration level that a consumer can safely open the door of the sealable volume  212 . 
     For instance, as shown in  FIG. 5 , after the fifth dosage D 5  is injected into sealable volume  212  by ozone generator  232 , controller  220  ascertains at ( 310 ) that the concentration level of ozone O 3  within sealable volume  212  has reached the maximum concentration level threshold T MAX , and accordingly, controller  220  ceases causing ozone generator  232  to inject predefined ozone dosages into sealable volume  212 . Thereafter, at ( 318 ), controller  220  can ascertain whether the concentration level determined at ( 316 ) has reached the minimum concentration level threshold T MIN . After reaching the maximum concentration level threshold T MAX , the concentration level of ozone O 3  within sealable volume  212  decreases over time. As the concentration level of ozone O 3  decreases, controller  220  can monitor the concentration level, e.g., at ( 316 ), and can ascertain whether the concentration level has reached the minimum concentration level threshold T MIN . Controller  220  can ascertain whether the concentration level has reached the minimum concentration level threshold T MIN  continuously or at a predetermined time interval. Eventually, as depicted in  FIG. 5 , the determined concentration level reaches the minimum concentration level threshold T MIN . If the concentration level has reached the minimum concentration level threshold T MIN  (e.g., as shown in the first and second scenarios of  FIGS. 5 and 6 , respectively), then the method ( 300 ) proceeds to ( 324 ). If the concentration level has not reached the minimum concentration level threshold T MIN , then method ( 300 ) proceeds to ( 320 ), and the logic remains in the ( 316 ), ( 318 ), and ( 320 ) loop until the concentration level reaches the minimum concentration level threshold T MIN  at ( 318 ) or a predetermined removal time elapses as determined at ( 320 ). 
     At ( 320 ), if the concentration level has not reached the minimum concentration level threshold T MIN , then the method ( 300 ) includes determining whether a predetermined removal time has elapsed. For instance, controller  220  can maintain a timer or clock. The timer can be started when controller  220  ascertains at ( 310 ) that the concentration level determined at ( 308 ) has reached the maximum concentration level threshold T MAX  or at another suitable time, e.g., when the ozone destructor device  238  is activated at ( 314 ). If the predetermined removal time has not elapsed as determined at ( 320 ), then method ( 300 ) reverts to ( 316 ) and ( 318 ) to continue monitoring the concentration level. If, however, the predetermined removal time has elapsed as determined at ( 320 ), then the method ( 300 ) proceeds to ( 322 ). 
     In some implementations, particularly where appliance  200  includes ozone destructor device  238  and activates ozone destructor device  238  at ( 314 ), the predetermined removal time can correspond with a maximum destructor on time. In this way, ozone detector device  238  is prevented from running indefinitely in the event of a failure condition. In yet other implementations, particularly where appliance  200  includes venting conduit  240  and damper  242  and causes damper  242  to move to the open position to allow for ozone O 3  to exhaust out of sealable volume  212  through venting conduit  240 , the predetermined removal time can correspond with a maximum exhaust time. In this manner, controller  220  need not attempt to exhaust ozone O 3  indefinitely, which may be of particular importance if sealable volume  212  is a chilled or otherwise conditioned chamber. 
     At ( 322 ), the method ( 300 ) includes detecting a fault condition and setting a fault condition flag associated with the detected fault condition. For instance, as shown in  FIG. 4 , the logic of method ( 300 ) can reach fault detection block ( 314 ) by multiple paths. For instance, in one path, if the concentration level determined at ( 310 ) does not reach the maximum concentration level threshold T MAX  before the maximum generator on time has elapsed as determined at ( 312 ), the method ( 300 ) proceeds to ( 322 ). In addition, in another path, if the predetermined removal time has elapsed at ( 320 ), the method ( 300 ) proceeds to ( 322 ). Accordingly, controller  220  first determines the fault condition and then sets a fault condition flag accordingly, or based at least in part on the detected fault condition. 
     As one example, if the concentration level determined at ( 310 ) does not reach the maximum concentration level threshold T MAX  before the maximum generator on time has elapsed as determined at ( 312 ), the detected fault condition can be at least one of 1) the ozone generator  232  has failed; 2) the ozone detection device  234  has failed; or 3) the sealable volume  212  is not sealed or air-tight, and accordingly, the injected ozone O 3  may be leaking from sealable volume  212 . Based on the detected fault condition, controller  220  can set an associated fault condition flag. 
     As another example, if the predetermined removal time has elapsed at ( 320 ) and thus for some reason appliance  200  is unable to remove or reduce the ozone concentration level within sealable volume  212 , the detected fault condition can be at least one of 1) the ozone destructor device  238  has failed (and thus the maximum destructor on time has elapsed at ( 320 )); or 2) the damper  242  has failed or is clogged (and thus the maximum exhaust time has elapsed at ( 320 )), among other possible fault conditions. Based on the detected fault condition, controller  220  can set an associated fault condition flag. Moreover, in some implementations, if the predetermined removal time has elapsed at ( 320 ), or more particularly, if the maximum destructor on time has elapsed at ( 320 ), the method ( 300 ) can further include deactivating ozone destructor device  238 . Further, in some implementations, if the predetermined removal time has elapsed at ( 320 ), or more particularly, if the maximum exhaust time has elapsed at ( 320 ), the method ( 300 ) can further include deactivating air handler  236  and/or causing damper  242  to move to the closed position. 
     At ( 324 ), if the determined concentration level has reached the minimum concentration level threshold T MIN  as ascertained at ( 318 ), the method ( 300 ) includes deactivating one or more ozone removal devices. As one example, if ozone destructor device  238  is activated at ( 314 ) and the determined concentration level has reached the minimum concentration level threshold T MIN , then deactivating the one or more ozone removal devices can include deactivating ozone destructor device  238 . In this way, ozone destructor device  238  can be turned off. As another example, if ozone destructor device  238  is activated at ( 314 ) and the determined concentration level has reached the minimum concentration level threshold T MIN , then deactivating the one or more ozone removal devices can include causing damper  242  to move to the closed position, e.g., to prevent air from escaping sealable volume  212  through exhaust conduit  240 . As yet another example, deactivating the one or more ozone removal devices can include deactivating air handler  236 . 
     At ( 326 ), the method ( 300 ) includes terminating the odor removal cycle. As shown the odor removal cycle can be terminated at ( 326 ) after deactivating the ozone devices at ( 324 ) or can be terminated after detecting a fault condition at ( 322 ). At the termination of the odor removal cycle, various information can be presented, e.g., to a user via a display of appliance  200 . For instance, the degree or amount of odor, bacteria, viruses, and/or other contaminants within sealable volume  212  can be measured or calculated based on the amount of time it takes to remove them from sealable volume  212 . For instance, the time can be measured from a start time to an end time. The start time can be associated with a time in which the first dosage of ozone is injected into sealable volume  212 . The end time can be associated with a time in which the concentration level reaches the maximum concentration level threshold T MAX . Other information can also be presented to the user as well. 
     In some implementations, the method ( 300 ) includes causing a door lock to lock a door of the appliance in the closed position during the odor removal cycle, e.g., from ( 302 ) to ( 326 ). For instance, controller  220  can cause, prior to causing ozone generator  232  to inject the predefined dosage of ozone O 3  into sealable volume  212  at ( 304 ), door lock  216  to lock door  214  in the closed position. Then, if controller  220  ascertains that the determined concentration level has reached the minimum concentration level threshold T MIN  at ( 318 ), controller  220  can cause door lock  216  to unlock such that door  214  can once again be opened. Accordingly, controller  220  can prevent a user from inadvertently interrupting the odor removal cycle and can protect a user from exposure to potentially unsafe levels of ozone O 3 . 
     An appliance equipped with an ozone monitoring system and control logic of method ( 300 ) described herein can provide a number of advantages and benefits. For instance, the ozone monitoring system provided herein and implemented by the method can remove odor/bacteria from various appliances, including refrigerator, laundry, and air-conditioner appliances. Further, consumer safety is ensured by only injecting predefined amounts of ozone to remove odor/bacteria and can include a door lock mechanism to ensure consumers are not inadvertently exposed to unsafe levels of ozone. Moreover, consumers can execute an ozone removal cycle to remove odor/bacteria by using a small amount of energy without using heat energy. 
     This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.