Patent Publication Number: US-2016235218-A1

Title: Energy Saving Food Display Cabinet

Description:
TECHNICAL FIELD 
     The invention relates to a method of optimising the energy consumed by a food display cabinet, in particular food display cabinets in which food is placed in a retail environment for display to end users. 
     BACKGROUND TO THE INVENTION 
     In food retail environments food must held in food display units/cabinets at temperatures appropriate to the food contained within the unit. Accordingly, hot foods, or drinks, are held at elevated temperatures (typically around 50° C. to 80° C. depending on the foodstuff), other products may be held at ambient temperature (typically around 20° C.) or chilled (typically around 5° C.) or frozen (typically around −20° C.). Such cabinets are therefore extensively used by the end user e.g. a customer in a supermarket, and therefore are designed to be used without specialist training. Such food display units are known in retail environments, such as shops, supermarkets, cafes etc, for the presentation of foodstuffs for a consumer to purchase. 
     In a food retail environment multiple food display cabinets are typically required, with each unit being held at a constant temperature. A cabinet/unit may be defined as having a number of shelves on which produce in placed, and the temperature across the entire unit is kept constant. Therefore if a retailer were to sell items at different temperatures multiple units are typically required, each unit being held at a different temperature. Such units can only perform a single function generally within the unit&#39;s interior that creates a single temperature across the entire food display unit. 
     The temperature of a given food display cabinet or unit typically remains constant during the day. Where the unit is heated, or chilled, the average power consumption of a unit may be of the order of 3 kW/hr. Over the course of a year due to the level of energy consumption, a significant amount of energy is consumed. Whilst improvements have been made in the efficiencies of such food display units, the amount of energy utilised (and accordingly the cost of running such units) remains significant. 
     According to an aspect of the invention there is provided a food display cabinet having a plurality of food display zones, wherein each food display zone includes a temperature regulating device and is configurable to be held at the same or different temperatures, the food display cabinet having a controller to control the temperature of each of the food display zones, the controller configured to: receive indicia of an item to be placed in a first food display zone; identify a temperature profile associated with the item; vary the temperature of the first food display zone, using the heat exchange element, so that the first food display zone is at the identified temperature for the item. 
     There is also provided a method of operating a food display cabinet having a plurality of food display zones, wherein each food display zone includes a temperature regulating device and is configurable to be held at the same or different temperatures, the food display cabinet having a controller to control the temperature of each of the food display zones, the method comprising the steps of: receiving indicia of an item to be placed in a first food display zone; identifying, based on the received indicia, a temperature profile associated with the item; varying the temperature of the first food display zone, using the heat exchange element, so that the first food display zone is at the identified temperature for the item. 
     Therefore the present invention ensures that the temperature of the food display zone is optimised during the course of the day to the appropriate temperature for the food to be stored in food display zone. As well as reducing the energy consumed, the present invention allows for fewer display units to be used in a store. By allowing the temperature of each zone to be changed during the course of a day the invention allows for foodstuffs of differing temperatures to be displayed in the same unit during the course of day. Such an arrangement is found to lead to significant energy savings over the lifetime of the food display unit. 
     Other aspects of the invention will be apparent from the appended claim set. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the invention are now described, by way of example only, with reference to the accompanying drawing in which: 
         FIG. 1  is a schematic of the apparatus according to an aspect of the invention; 
         FIG. 2  is a schematic of the system according to the first aspect of the invention; 
         FIG. 3  is a flow chart of the process according to an aspect of the invention; and 
         FIG. 4  is experimental data illustrating an example of the invention. 
     
    
    
     DETAILED DESCRIPTION OF AN EMBODIMENT 
     According to an aspect of the invention there is provided multi-zone food display cabinet which optimises its energy consumption over the course of the day. 
     In an embodiment of the invention the multi-zone food display unit is a FlexeServe-Zone cabinet as sold by Alan Nuttall Limited and as described in GB patent GB 1316909.9 filed in the name of Alan Nuttall Limited. 
     Such cabinets comprise several separate and thermally discreet zones (four in this embodiment) in which food is held and displayed to the end user, such as a customer in a cafe or supermarket. Each zone is thermally insulated from the other zones and the temperature of each zone may be controlled independently of the other. Such a configuration allows for different foods to be kept at different temperatures within the same unit. For example a unit may contain a mixture of chilled and ambient foods in different zones. Therefore the owner of a retail unit would only require a single cabinet to store food items at different temperatures whereas previously they would have required two or more cabinets. 
       FIG. 1  shows a schematic representation of a food display cabinet in accordance with an embodiment of the invention. 
     There is shown the food display unit (or cabinet)  10 , the food display cabinet comprising multiple food display zones. There is shown the first zone  12 , second zone  14 , third zone  16  and a fourth zone  18 . 
     Each zone is thermally insulated from the other zones, and comprises a top panel  20 , base panel  22 , temperature regulating device  24  and a temperature sensor  26 . The individual zones are controlled by a controller  28  which is preferably integrated within the food display unit  10 . As such, the cabinets are used for the display of food, in a preferred embodiment the unit is an open fronted cabinet which allows the end user easy access to the products being displayed. Such food display cabinets therefore do not cook the food placed in the zones. Rather they are used in retail environments to present produce to the consumer. 
     In the embodiment shown in  FIG. 1 , the food display unit  10  comprises four food display zones though in further embodiments the number of food display zones may vary. Preferably, the food display zones are stacked vertically on top of each other such that when in use in a retail environment, each zone is easily accessible by a user without the user having to move from their initial position. 
     The top panel  20  of each zone is preferably insulated in order to prevent thermal leakage between one or more of the food display zones. The top panel  20  may also have integrated thereon lights, and panels for indicating pricing information and/or branding or the like. 
     The base panel  22 , preferably is also insulated in order to prevent thermal leakage between the individual food display zones. Each food display zone ( 12 ,  14 ,  16  and  18 ) has an individual temperature regulating device  24 . 
     In a preferred embodiment the temperature regulating device  24  comprises the use of a thermocouple sensor that is preferably mounted onto the underside surface of the base cover material  22  which is connected to an electronic controller  28  which responds to variations in set temperatures to turn on or off heating or cooling means within the constraints of that specific food display zone. Set onto the underside of base surface  22  is a resistive heater means that is overlaid with a surface material that is preferably a glass or ceramic glass. The temperature regulating device on the rear panel  24  is by heater means that is accompanied with a radial fan(s) to distribute hot air into the specific food display zone by way of a ducted chamber running under the top of the zone and distributed as an air curtain over the front aperture of the specific zone to be recaptured back into the specific zone for recycling over the heater element(s). 
     Preferably, the base heater and the rear heater means are independent and can be used simultaneously or separately to provide heating means for the specific food display zone. For the cooling of a specific food display zone, the heater elements in an embodiment would be replaced by a cooling coil preferably a vapour evaporation device or some other form of heat exchange device configured to cool the specific food display zone. The base material  22  is preferably glass or ceramic glass with the thermocouple sensor on the under surface. 
     Dependant on the envisaged usage of the food display cabinet  10  the temperature regulating device  24  may be selected so as to maintain the contents of the individual food display zones within a desired temperature range. For example, in embodiments in which the food display unit is envisaged to mostly hold warm or hot food items (which according to Food Safety Regulations require the zone to be held at a temperature of 70° C. or above) then the temperature regulating device  24  need not contain a refrigeration device as such a component would be redundant. In further embodiments the temperature regulating device  24  may contain both refrigerating and heating elements. Preferably, the temperature regulating device  24  comprises a plurality of fans in order to circulate the air contained in the volume space defined by each of the food display zones. 
     In further embodiments the food display cabinet is a modular unit in which individual modules may be combined to define a food display unit having multiple food display zones. Accordingly the term food display unit may refer to a singular unit or a modular unit in which the modules are combined to define the food display unit. 
     The structure of such a food display unit in a preferred embodiment of the invention is described in detail in GB patent application GB 1316909.9 in the name of Alan Nuttall Limited. The contents of which are hereby incorporated by reference. 
     In use, the food display unit therefore allows for the display of multiple different food items to be held at different temperatures within the same food display unit  10 . Accordingly, a food display unit  10  may comprise a mixture of hot and cold food display zones each zone containing a different food type or types. In addition to having the zones heated, cooled or ambient, a food display zone can be set to ‘off’ and have no form of energy expended in that specific zone. For example, the first zone  12  may contain hot soups or the like, whereas the second zone  14 , third zone  16  and fourth zone  18  may contain a number of cooled or chilled items. As the invention relates to a food display unit, or cabinet, which is designed to be used in a retail environment the construction of the unit is such that the end user is able to utilise the cabinet as any other standard food display unit. 
     The inventors have realised that whilst the ability to maintain the individual food zones at different temperatures provide further flexibility with regards to the display and presentation of food items, the energy consumption associated with such a food display unit  10  may increase over a working day in particular, if a number of the food display zones are to be held at a temperature other than ambient (i.e. heated or cooled). Accordingly, an aspect of the present invention is the ability of the controller  28  to change the energy profile of the individual zones in order to maintain a food display zone at required temperature at a given time to reduce the energy consumption associated with the food display cabinet. 
     Accordingly, in order to minimise the energy consumption associated with a food display unit  10  according to an aspect of the invention there is provided a system which is able to identify a food type, an optimum temperature associated with the food type, and a duration for which the particular food type will be placed in the food display zone. In retail environments it is known to vary the foodstuffs held in a food display zone over the course of a day. In particular, in environments such as cafes, or sandwich bars, which typically vary the items for sale over the course of a day. For example, some items would only be presented at breakfast time and removed from the food display unit  10  later in the day. Furthermore, when trading is slow (for example towards the end of the trading day) the unit can have zones that are ‘off’ i.e. no power is supplied to them, and therefore the display unit  10  can display only the quantity of food required for that trading period. This provides further significant power savings as the display is not utilising energy on empty zones. This is in contrast to traditional cabinets which operate at a set temperature in all of the areas within the cabinet regardless of the quantity of product on display (even when a given food display zone is empty) using the same amount of energy. 
     According to an aspect of the invention, the controller  28  is configured to individually vary the temperatures (if heated, the heat source of either conductive or convective heat from either heater means at  22  or heater means at  24 ) of each of the food display zones during the course of the day in order to provide an optimal temperature for each zone. Accordingly, each of the food display zones, unlike in the prior art, will vary in temperature and the energy consumption associated with each zone will also vary during the course of the day. By determining an optimal temperature for each zone over the course of a day (the temperature of the zone being variable) the energy consumed by each of the individual food display zones decreases, and accordingly, the overall energy consumption of a food display unit  10  also decreases. 
       FIG. 2  shows a schematic representation of an energy saving system according to an aspect of the invention. 
     There is shown in  FIG. 2  the food display cabinet/unit  10 . The food display unit  10  is controlled by the controller  28  (which is preferably attached to a slave controller  28 A for each individual zone) and is as described with reference to  FIG. 1 . The system further comprises one or more input devices  30 , a computing device  32 , a database  34  and a display  36 . 
     The input device  30  in a preferred embodiment is a scanner associated with the food display unit  10 . The input device  30  in an embodiment is integrated within each of the food display zones, and in a further embodiment is a handheld device with which a user is able to scan in data associated with the food item, such as barcode, or other form unique identifier. In the preferred embodiments the one or more input devices  30  are in communication with the central computer  32 . Such communication is wired or wireless. 
     In a preferred embodiment the input device  30  is a scanner, though in further embodiments the input device  30  is a keyboard or the like in which a user is able to input identifying information to the computer  32 . Preferably, the computer  32  is separate from the food display unit  10  though in further embodiments the computer  32  is integrated within the food display unit  10 . 
     The computer  32  is configured to access information from a database  34 . In a preferred embodiment the database is held within the computer  32 , though in further embodiments the database is held separate to the computer  32  such as in the cloud. The computer  32  and database  34  communicates using known means. Optionally, the computer  32  is further configured to output to a separate display unit  36 . 
     Typically, in use the food one or more food display cabinets  10  are placed within the “shop floor” environment and the computer  32  is held within a “back office” i.e. away from the retail/shop floor environment. 
     In use, at the start of the day, an operative will use the input device  30  to input data relating to the food items to be held within each food display zone. As well as inputting information relating to the food type (preferably in the form of a unique identifier), information regarding the food display zone in which the product is to be placed (i.e. the first food display zones  12 , second food display zone  14  etc.) is also inputted as well as the length of time said product will be kept in the food display zone. Once inputted, the computer  32  is configured to query the database  34  using the inputted data from which the food type may be identified, in order to determine an optimal temperature profile for the food type. The optimal temperature profile depends on the food type as well as any relevant Food Safety Legislation that must be complied with regarding the display of food items. The temperature profile and optimum display time are preferably held in the database  34  which is queried by the computer  32  and assigned to a specific zone within the unit  10 . The initial recognition of the unique record or ‘recipe’ for the food stuff that is either chosen from a stored list in database  34  or recognised by the device  30  or other means of identification and the ‘recipe’ for that unique identification is then made available from the database for assignation to a zone. The computer  32  is further configured to transmit information to the controller  28  in order to maintain the temperature of the individual food display zones at the correct temperature via the slave controller  28 A which is assigned to that specific zone. 
     In a further embodiment, one or more of the information regarding the food display zone, time the food item is placed in a zone, and length of time a food item is to be held in a particular zone is held in the database  34  and retrieved once the information identifying the food item has been inputted at the input device  30 . 
     This process is described in detail with reference to  FIG. 3 . 
       FIG. 3  shows a flow chart of the process of determining the optimal energy profile over a period of time, such as a working day for a food display cabinet/unit  10 . The ability to adapt the energy usage profile of the food display unit over the course of a day is found to result in a significant decrease in the energy consumption of the food display unit, especially when compared to the standard profile which would involve running an entire food display unit at the same temperature throughout the course of the day. 
     It is known in the retail industry that the position of placement of an item within a food display cabinet  10  will affect the subsequent visibility and sale of the item to consumers. For example, it is known that the second zone  14 , which is at approximately eye level, is typically the zone in which the most number of items are sold. Accordingly, when new items are introduced (for example a new product or a new range) then a retailer may typically place such an item in the second zone  14  in order to promote said item. 
     The process of optimising the energy profile is now described with reference to  FIG. 3 . 
     At step S 102 , the user inputs data regarding the food item or items to be placed within a food display zone of the food display cabinet  10 . One or more different items may be placed within an individual display zone (i.e. first zone  12 , second zone  14 , third zone  16 , fourth zone  18 ) though each item must be placed with items which are to be kept, and displayed, at the same temperature. As described previously with reference to  FIG. 2 , the data regarding the food items is inputted using the input device  30 . 
     At step S 104  each item is identified using the data from the input device  30 . In an embodiment, the unique identifier identifying the foodstuff will also identify one or more of a food display zone in which the item is to be placed, a period of time for which the item is to be placed within a food display zone, and the time in which the item is to be placed within a food display zone. In further embodiments, further data may be inputted via the input device  30  which one or more of identify the food display zone and the period of time in which the item is placed within said food display zone. In a further embodiment, the information regarding the particular zone and length of time the item is held within said zone is already held in the database  34 , and accordingly, the scanning of the item using the user input device  30  retrieves such information. 
     Once the item has been identified, along with the food display zone and the period of time said item is to be placed in the zone, optimal temperature profile is identified/calculated for each of the food display zones at step S 106 . The optimal temperature profile for a foodstuff depends on the particular foodstuff, and the relevant safety standards associated with the product. For example, items such as sandwiches are required to be held at a temperature of between 4° C. and 8° C. 
     At step S 108  the system determines for each of the individual food display zones, any transition times which are anticipated during the day. For example, a first food display zone  12  may contain and display warm pastry products between the hours 7.00 am and 11.00 am, which are to be held at a temperature of 50° C. (i.e. in the example between the hours of 7.00 am to 11.00 am warm pastries are offered for sale from food display zone  12 ). After 11.00 am, the first food display zone  12  may be stocked with sandwiches which are to be held at a temperature of 4° C. to 8° C. (i.e. in the above example, after 11.00 am warm pastry products are no longer displayed in the first food display zone  12 , and are replaced by sandwiches). Subsequently, after 4 pm the first food display zone  12  is stocked with crisps which are kept at ambient temperature. Accordingly, the products displayed and offered for sale vary over the course of the day, and the temperature of the first food display zone  12  would change over the course of the day to accommodate the display of different products. The temperatures and times that an individual food display zone changes over time varies according to the individual requirements of the environment in which the system is placed. 
     At step S 108  for all food display zones during the desired time period (e.g. a day) each transition time (i.e. when the time at which the temperature of the individual zone is to change) is determined. 
     At step S 110 , the system calculates an optimum efficient energy transition profile for each transition time determined at step S 108 . The items which remain in a given food display zone at the end of the shelf life time of the item (for example the pastry products which remain unsold at 11.00 am in the above example) are removed from the food display zone and are typically thrown away or placed in a different zone. In order to ensure maximum effectiveness of the food display cabinet/unit  10  in a preferred embodiment the individual food display zones are at the required temperature at the time the new item is placed in the given food display zone. Illustratively, in the above example, the first food display zone  12  would be at the required temperature for sandwiches (i.e. between 4° C. to 8° C.) at 11.00 am. At step S 110 , the optimum energy transition time profile is therefore determined using the calculated transition time. The calculation of the transition time is dependent on the difference in temperatures, the strength of the temperature regulating device  24 , as well as the maximum energy efficiency that the system wishes to attain. 
     Preferably the transition Time Calculation is as below: 
       Δ Tr =( Ht−Lt )/3
 
     where 
     ΔTr is the transition time in minutes 
     Ht is the highest temperature for the zone in Degrees C 
     Lt is the lowest temperature for the zone in Degrees C 
     In further embodiments other methods of determining the transition time may be used. 
     Once the energy transition profiles have been determined, the optimal energy profile for the period of time (e.g. a day) is calculated at step S 112  and inputted to the controller  28 . The controller  28  varies the temperature of the individual food display zones according to the calculated optimum energy profile over the course of the day. As each food display zone further comprises a temperature sensor  26 , the controller  28  is able to maintain the temperatures as required during the course of the day. 
       FIG. 4  shows an example of a typical temperature profile for a first food display zone across the course of a day.  FIG. 4  shows how the temperature varies across the course of a day. 
     In the morning, at approximately the 10:15 the unit is switched on and the temperature is increased to operating temperature of approximately 50° C. at 11:30. Products such as warm soup may be held at this temperature. Between 11:30 and the transition point at 12:45 the temperature is kept approximately constant at 50° C. The variations shown are typical for food display units where the temperature regulating device  24  (in this instance conduction heating via the base heater at  22 ) switches on and off in order to maintain the temperature of the food display zone within the desired range. From the information inputted (i.e. at step S 102  of  FIG. 3 ) it is determined at approximately 13:00 hot food will be placed in the food display zone. Accordingly, between the first transition point (12:45) and 13:00 the temperature of the zone is increased. 
     The temperature is kept at approximately constant temperature (here −75° C.) until the second transition time. From the information inputted at step S 102  it is determined that at 16:00 foodstuffs which are to be held at approximately −55° C. are to be placed in the food display zone. Accordingly at 15:50 the temperature of the food display zone is decreased so that it is at the optimum temperature at 16:00. 
     Tests performed by the inventors have shown that the methodology of the claimed invention may result in significant energy savings. Tests performed over the duration of a typical working day (12 hours) using a varying temperature plan as per the above described process reduces the typical energy consumption of a unit by approximately 25% for a unit that would typically run at 75° C. (test show a reduction in energy consumption from approximately 3.08 kW/h to 2.37 kW/h). 
     As well as reducing the energy consumption of an individual food display unit  10 , the system has further benefits in adding stock management. As the system is designed to ensure that the temperature of the food zones is optimised for a product at a given time (in particular with reference to the transition between temperatures) this information, in an embodiment is also by the computer  32  to manage stock. 
     If the foodstuff in a particular zone is known to have a limited shelf life (e.g. a couple of hours) and that the product is approaching the end of the shelf life the computer is configured to display messages, via the display  36 , to inform a user of the unit (e.g. a member of staff) who may act accordingly. For example, the message may be to reduce the price of a product. 
     Furthermore, the computer  32  is configured to display messages via the display  36  regarding a transition. This would allow members of staff to prepare for the switching of stock. For example, if a foodstuff to be placed in the first food zone  12  is to be prepared and cooked, said preparation and cooking taking  35  minutes, then at an appropriate time messages are displayed to inform the staff to commence preparing and cooking the foodstuff. In a further embodiment, separately or in conjunction with the display  36  an audible alarm may be used. 
     Therefore the system may aide in providing a more efficient transition between foodstuffs for a given food display zone.