Patent Description:
Refrigerated enclosures and refrigerated display cases are common storage solutions for produce and other products requiring refrigeration in supermarkets throughout the world. Some enclosures may be small scale solutions, where a customer can open a door of a refrigerated case to access shelves of produce or reach into an open refrigerated display case. Other enclosures may be large scale solutions, where a customer may enter an enclosed refrigerated environment or large space to access refrigerated products. However, both small and large scale refrigeration systems face challenges in both keeping the product cool while reducing heat transfer into the refrigerated space when either a door or an entrance to the refrigerated space is open to ambient temperatures. Similar refrigerated enclosures / displays are known from <CIT>, <CIT>and <CIT>.

According to the invention, the present disclosure relates to an accessible cooling environment comprising:
a back wall, an opening opposite the back wall, a roof panel, first and second side walls at least partially defining the opening, and an interior space at least partially defined by the back wall, roof panel, and first and second side walls; at least one fan configured to circulate air through the interior space; an evaporator disposed inside the interior space; an air curtain assembly configured to form an air barrier adjacent to the opening, the air curtain assembly including one or more deflectors for separating the air barrier into a first air curtain and a second air curtain; and a diffuser having a plurality of channels and a variable height as the diffuser extends between the first and second side walls.

In a preferred form, the air barrier may include a first air curtain at a first temperature and a second air curtain at a second temperature lower than the first temperature.

In another preferred form, the one or more deflectors of the air curtain assembly may be disposed between the opening and the fan to separate the first and second air curtains.

In another preferred form, the air barrier may include a third air curtain having a temperature lower than the temperature of the second air curtain.

In a preferred form, the temperature of the first air curtain may be in a range of approximately <NUM> degrees Fahrenheit (<NUM>,<NUM> degrees Celsius) to approximately <NUM> degrees Fahrenheit (<NUM> degrees Celsius).

In a preferred form, the temperature of the second air curtain may be in a range of approximately <NUM> degrees Fahrenheit (<NUM>,<NUM> degrees Celsius) to approximately <NUM> degrees (<NUM>,<NUM> degrees Celsius).

In a preferred form, the temperature of the third air curtain may be in a range of approximately <NUM> degrees Fahrenheit (-<NUM>,<NUM> degrees Celsius) to <NUM> degrees Fahrenheit (<NUM>,<NUM> degrees Celsius).

In a preferred form, the first air curtain may be adjacent to the opening, the third air curtain may be adjacent to the interior space, and the second air curtain may be disposed between the first and the third air curtains.

In a preferred form, the at least one sensor may include a first sensor disposed at the input of the evaporator and a second sensor disposed in the coil of the evaporator.

In a preferred form, the one or more processors may be configured to compare sensor data at the input of the evaporator with the sensor data in the coil of the evaporator.

In a preferred form, the one or more processors may be configured to compare sensor data of the at least one sensor.

In a preferred form, the one or more processors may be configured to send a signal to the evaporator to raise the temperature of the evaporator to initiate a defrost cycle.

In a preferred form, a seal may be disposed between the barrier and at least one of the first and second side walls.

In a preferred form, the seal disposed between the barrier and the at least one of the first and second side walls may be a brush seal.

In a preferred form, a seal may be disposed between the barrier and the floor when the barrier is in the closed position.

In a preferred form, the seal disposed between the barrier and the floor may be a bulb seal.

In a preferred form, a barrier may be disposed in the opening and extend between the first and second side walls.

In a preferred form, the barrier may be movable from a closed position, in which the barrier sealingly engages a floor and an open position, in which the barrier is spaced away from the floor.

In a preferred form, a seal disposed between the barrier and at least one of the first and second side walls.

In a preferred form, the seal disposed between the barrier and the floor may be a compressible seal.

In a preferred form, the barrier may at least partially channel air flow of the air barrier.

In a preferred form, the accessible cooling environment may include a defrost system connected to the evaporator.

In a preferred form, the defrost system may include at least one sensor coupled to the evaporator and configured to capture sensor data associated with a temperature of at least one of an input and a coil of the evaporator.

In a preferred form, the at least one sensor includes a first sensor disposed at the input of the evaporator and a second sensor disposed inside of the evaporator.

In a preferred form, the defrost system may include one or more processors.

In a preferred form, the defrost system may include a memory communicatively coupled to the one or more processors and storing executable instructions that, when executed by the one or more processors, may cause the one or more processors to receive sensor data captured by the at least one sensors, analyze the sensor data to identify a status or condition associated with the evaporator, and send a signal to the evaporator to heat or cool based on the status or condition identified.

In a preferred form, an embedded heating element may be disposed adjacent to the opening.

In a preferred form, the air curtain assembly may include a blower and at least one fan of the evaporator.

In a preferred from, the fan may include a blower at least partially disposed outside of the interior space.

In a preferred form, the fan may include multiple fans of the evaporator.

The present disclosure is generally directed to an open-wall cooler ("OWC") unit, also referred herein as an accessible cooling environment unit, an open-walled, temperature-controlled environment, and an open-walled refrigeration unit, which may be a standalone unit or configured in a layout comprising a plurality of OWC units. The OWC unit may replace existing small and large scale refrigeration solutions by providing an energy-efficient refrigerated environment that is easy to construct and provides a comfortable shopping experience for the consumer.

In <FIG>, an OWC unit <NUM> is assembled in accordance with the teachings of the present disclosure. The OWC unit <NUM> is a partially enclosed, refrigerated storage space including a back wall <NUM>, an opening <NUM> opposite the back wall <NUM>, a roof <NUM>, and first and second side walls <NUM>, <NUM> that partially define the opening <NUM>. An interior space <NUM> is defined by a ground or floor surface <NUM>, the back wall <NUM>, roof panel <NUM>, and first and second side walls <NUM>, <NUM>. A barrier <NUM> also at least partially defines the interior space <NUM> and is disposed in the opening <NUM> between the first and second side walls <NUM>, <NUM>. The barrier <NUM> sealingly engages the floor or ground <NUM> when in the closed position, and is movable to an open position (as shown in <FIG>), in which the barrier <NUM> is spaced away from the floor or ground <NUM>. As will be discussed further below, the barrier <NUM> provides the OWC unit <NUM> with both a physical and thermal barrier from the external environment.

The OWC unit <NUM> has a refrigeration system <NUM> that maintains the temperature of the interior, and distributes refrigerated air throughout the interior space <NUM>. The refrigeration system <NUM> includes a condenser <NUM> disposed on the roof <NUM>, an evaporator <NUM> (shown in <FIG>) disposed in the interior space <NUM>, a blower <NUM> disposed on the roof <NUM>, and an insulated duct <NUM> connecting the blower <NUM> and the interior space <NUM> of the OWC unit <NUM>. A control system <NUM> is disposed on the roof <NUM>, the interior space <NUM>, or in the evaporator <NUM>, and is coupled to the refrigeration system <NUM> to monitor, analyze, and control the refrigeration system <NUM> of the OWC unit <NUM>. For example, the control system has a demand defrost cycle that keeps the evaporator <NUM> functioning at high efficiency. The control system <NUM> may be operated remotely or locally to operate the defrost cycle, change temperature or fan speed, or control and/or operate other functions of the refrigeration system <NUM>. The control system <NUM> may include one or more sensors coupled to the evaporator <NUM> or other areas in the interior space <NUM> of the OWC unit <NUM>, one or more processors <NUM>, and a memory <NUM> for storing executable instructions that enables automatic operation of the defrost cycle and/or other features or programs of the refrigeration system <NUM>. While the refrigeration and control systems <NUM>, <NUM> are arranged on (or near) the roof <NUM> of the OWC unit, in other examples, the refrigeration and control systems <NUM>, <NUM> may be arranged differently. For example, the blower <NUM>, the condenser <NUM>, and the control system <NUM> may be disposed on the exterior of the OWC unit <NUM>, on the ground <NUM>, or attached to any of the panels defining the OWC unit <NUM>.

The roof <NUM>, sidewalls <NUM>, <NUM>, and back wall <NUM> of the OWC unit <NUM> of <FIG> are preferably constructed using connected insulated panels. The roof <NUM> may be constructed of one or more insulated panels joined together. Similarly, each of the first and second side walls <NUM>, <NUM> includes a single insulated panel that is connected to the both the roof <NUM> and the back panel <NUM> via insulated frames. The back panel <NUM> may include one or more joined insulated panels that attach to the roof and the first and second sidewalls <NUM>, <NUM>. In one example, the OWC unit <NUM> may have a length (i.e., extending between the first and second side walls <NUM>, <NUM>) of approximately <NUM> feet (<NUM>,<NUM> meters), a height (i.e., extending between the ground surface <NUM> and the roof <NUM>) of approximately <NUM> feet (<NUM>,<NUM> meters), and a width (i.e., measured between the opening <NUM> and the back wall <NUM>) of approximately <NUM> feet (<NUM>,<NUM> meters). However, in other exemplary OWC units <NUM>, these dimensions may vary. For example, the side walls <NUM>, <NUM> and/or back wall <NUM> may include a plurality connected insulated panels depending on the desired size and shape of the OWC unit <NUM>. In other words, the OWC unit <NUM> may be customized. The panels may be connected to each other by a hybrid insulated frame, such as the hybrid frames disclosed in <CIT>, titled "Insulated Structural Members for Insulated Panels and a Method of Making Same," <CIT>, titled "Method of Manufacturing Hybrid Insulation Panel," and <CIT>, titled "Hybrid Insulating Panel, Frame, and Enclosure". In other examples, the frames may be wood, metal, composite, foam, or a combination of materials.

Turning now to <FIG>, a partial OWC unit <NUM> of <FIG> is illustrated. In <FIG>, a portion of an air curtain assembly <NUM> is depicted and includes one or more fans or blowers <NUM> of the evaporator <NUM>, one or more deflectors <NUM>, <NUM>, <NUM>, one or more perforated ceiling plates <NUM>, and one or more back wall plates <NUM>, <NUM> disposed in the interior space <NUM> of the OWC unit <NUM>. However, the air curtain assembly <NUM> also includes the blower <NUM> of <FIG>, which is hidden in <FIG> for illustrative purposes. In this way, air is circulated through the OWC unit <NUM> by the blower <NUM> and/or the fans <NUM> of the evaporator <NUM>. The air curtain assembly <NUM> is configured to form and shape an air barrier <NUM> (in <FIG> and <FIG>) adjacent the opening <NUM> of the OWC unit <NUM> to reduce air exchange across the opening <NUM> and to bathe a product disposed in the interior space <NUM> with constant cold air. The barrier <NUM> also helps guide air flow from the opening <NUM>, against the ground <NUM>, and toward the back wall <NUM> within the interior space <NUM> of the OWC unit <NUM>. At the back wall <NUM>, air is then channeled into a duct <NUM> formed between the back wall <NUM> and the back wall plates <NUM>, <NUM>, where the air may be recirculated through the evaporator <NUM> or through the blower <NUM> and back into the OWC unit <NUM>.

A first and second curved deflectors <NUM>, <NUM> of the air curtain assembly <NUM> are curved turning vanes disposed in the interior space <NUM> adjacent to the roof <NUM> and between the fan <NUM> of the evaporator <NUM> and the opening <NUM> of the unit <NUM>. The two curved deflectors <NUM>, <NUM> create a plenum that channels the air into a first air curtain. The first curved deflector <NUM> forms one side of the plenum and the second curved deflector <NUM> creates the other side of the plenum. The two curved deflectors <NUM>, <NUM> create a sealed channel (like a funnel) where the air from the blower <NUM> flows through it and into the first air curtain. A third deflector <NUM> is an angled plate extending between the first and second side walls <NUM>, <NUM> and disposed between the perforated ceiling plate <NUM> and the roof <NUM>. The deflectors <NUM>, <NUM>, <NUM> are positioned within the flow path of the recirculated air of the OWC unit <NUM> to channel the air into separate pathways and at separate temperatures to create the vertical air barrier <NUM> at the opening <NUM>. The deflectors <NUM>, <NUM>, <NUM> may be metal deflectors, plastic honeycomb diffusers, or a combination of materials. As will be explained in further detail below, the deflectors <NUM>, <NUM>, <NUM> channel air into multiple air curtains where each air curtain has a different temperature to provide a temperature gradient at the opening <NUM> of the OWC unit <NUM> that limits heat exchange at the opening <NUM>.

As shown in <FIG>, a first wall plate <NUM> is spaced from the ground <NUM> and spaced from a second wall plate <NUM>, thereby forming a first opening or slot <NUM> with the ground <NUM> and a second opening or slot <NUM> with the second wall plate <NUM>. Air flows through either the first or second openings <NUM>, <NUM> into the duct <NUM>. The ceiling plate <NUM> allows airflow into the product space of the interior space <NUM> of the OWC unit <NUM>. In operation, the air curtain assembly <NUM> limits air intrusion into the interior space <NUM> of the OWC unit <NUM> and facilitates cooling of the product in the interior space <NUM>. The fans <NUM> of the evaporator <NUM> and the blower <NUM> on the roof <NUM> direct air towards the opening <NUM>, and the deflectors <NUM>, <NUM>, <NUM> divert the air to form a vertical air barrier and to distribute cool air evenly throughout the interior space <NUM>. The air from the air barrier <NUM> then circulates through the back duct <NUM> and either into the duct <NUM> and the blower <NUM> or into an input of the evaporator <NUM>.

As illustrated in a second exemplary OWC unit <NUM> shown in <FIG>, the deflector <NUM> may itself have multiple surfaces that are angled with respect to one another, to further direct air flow in desired directions. For instance, the deflector <NUM> may include inclined surfaces 168a and 168b that are pitched at an angle, lower toward a rear of the OWC unit <NUM> and higher toward a front of the OWC unit <NUM>, with the inclined surfaces 168a, 168b meeting along an apex 168c, such as along a center line of the OWC unit <NUM>, and each of the inclined surfaces 168a, 168b depending downwardly from the apex 168c in a direction toward respective side walls <NUM>, <NUM> of the OWC unit <NUM>. The apex flattens toward the rear of the OWC unit <NUM>.

As shown in <FIG>, air is recirculated through the OWC unit <NUM> according to the exemplary flow diagram. The vertical air barrier <NUM> is formed at the opening <NUM> and includes a first air curtain <NUM>, a second air curtain <NUM>, and a third air curtain <NUM>. The first, second, and third air curtains <NUM>, <NUM>, <NUM> each have a different temperature in a particular temperature range; the third air curtain <NUM> has the lowest temperature of the three air curtains <NUM>, <NUM>, <NUM>. The refrigeration system <NUM> and air curtain assembly <NUM> operate together to maintain the temperature of each air curtain <NUM>, <NUM>, <NUM> in each respective temperature range. While the illustrated example of the air barrier <NUM> includes three air curtains <NUM>, <NUM>, <NUM>, in other examples the air barrier <NUM> may include more or fewer than three air curtains <NUM>, <NUM>, <NUM>. Additionally, while the air barrier <NUM> is oriented to flow across the opening <NUM> in a vertical direction, in other examples, the air barrier may be oriented differently, such as horizontally, or at a different angle, depending on the location of the air curtain assembly <NUM>.

The first air curtain <NUM> is adjacent to the opening <NUM> and has the highest curtain temperature. For example, the temperature of the first air curtain <NUM> is in a range of approximately <NUM> degrees Fahrenheit (<NUM>,<NUM> degrees Celsius) to approximately <NUM> degrees Fahrenheit (<NUM> degrees Celsius), and preferably around <NUM> degrees Fahrenheit (<NUM>,<NUM> degrees Celsius). The blower <NUM> channels air through an opening in the roof <NUM>, into the interior space <NUM> and between the curved deflectors <NUM>, <NUM> to form the first air curtain <NUM>. A honeycomb diffuser assembly <NUM>, which may include one or more diffusers, is disposed at a bottom of the deflectors <NUM>, <NUM> and receives the first and second air curtains <NUM>, <NUM>. The honeycomb assembly <NUM> conditions the air flow to create laminar airflow across the opening <NUM> by reducing turbulence. The air flow forms the first air curtain <NUM> by flowing across the opening <NUM> in a vertical direction. The barrier <NUM> directs air flow from the first air curtain <NUM> into the interior <NUM> of the OWC unit <NUM> and against the ground <NUM>. The air then flows across the ground <NUM> toward the back wall <NUM>, and through the first opening <NUM> of the back wall plate <NUM> and into the back duct <NUM>. A portion of the air from the first curtain <NUM> is then channeled through the duct <NUM> connected to the roof <NUM> and through to the blower <NUM> to be recycled again through the OWC unit <NUM>. The air that forms the first air curtain <NUM> cycles along this path and does not enter the evaporator <NUM>.

The second air curtain <NUM> of the air barrier <NUM> is formed between the first and third air curtains <NUM>, <NUM>. Refrigerated air exiting the outlet fans <NUM> of the evaporator <NUM> enters the interior space <NUM> of the OWC unit <NUM> and forms either the second air curtain <NUM> or the third air curtain <NUM>. The angled and curved deflectors <NUM>, <NUM>, and <NUM> direct the cooled air through a space between the curved deflector <NUM> and an outer edge of the perforated ceiling plate <NUM>, forming the second air curtain <NUM>. In this way, the curved deflectors <NUM>, <NUM> separate the first and second air curtains <NUM>, <NUM> that form the air barrier <NUM> adjacent to the opening <NUM>. The curved deflector <NUM> also shapes the air from the evaporator <NUM> and directs it into the second air curtain <NUM>. A portion of the air being directed into the second air curtain <NUM> splits off and forms the third air curtain <NUM>. The air from the second air curtain <NUM> flows into the honeycomb assembly <NUM> and across the opening <NUM> and into the interior space <NUM> of the OWC unit <NUM>. A portion of the air from the second air curtain <NUM> may reach the ground another portion may flow across a lower portion of the interior space <NUM> (i.e., where stored product will be placed) and through the first opening <NUM> of the back wall plate <NUM> and into the back duct <NUM>, and another portion may flow through the optional second opening <NUM>. The air from the second air curtain <NUM> flows through the back duct <NUM> in a vertical direction and into an intake or input <NUM> of the evaporator <NUM> to be recycled again through the OWC unit <NUM>. The temperature of the second air curtain <NUM> is in a range of approximately <NUM> degrees Fahrenheit (-<NUM>,<NUM> degrees Celsius) to approximately <NUM> degrees Fahrenheit (<NUM>,<NUM> degrees Celsius), and preferably around <NUM> degrees Fahrenheit (<NUM>,<NUM> degree Celsius).

The third air curtain <NUM> is adjacent to the second air curtain <NUM> and the interior space <NUM> of the OWC unit <NUM>. The third air curtain <NUM> has a temperature in a range of approximately <NUM> degrees Fahrenheit (-<NUM>,<NUM> degrees Celsius) to approximately <NUM> degrees Fahrenheit (<NUM>,<NUM> degree Celsius) and preferably around <NUM> degrees Fahrenheit (<NUM> degree Celsius). As such, the third air curtain <NUM> has the lowest temperature of the air barrier <NUM>. Similar to the second air curtain <NUM>, cooled air exiting the evaporator <NUM> is channeled toward the opening <NUM> of the OWC unit <NUM>. The third air curtain <NUM> flows partially across the opening <NUM> and into an upper portion of the interior space <NUM> and through the second opening <NUM> formed by the back wall plates <NUM>, <NUM>. The air then flows into the input <NUM> of the evaporator <NUM> to be recycled again through the OWC unit <NUM>. In addition to the first air curtain <NUM>, a portion of the air from the second and third air curtains <NUM>, <NUM> can be recirculated in normal operations through the blower <NUM> and into the interior space <NUM>.

Turning to <FIG>, the OWC unit <NUM> may include a height-adjustable shelf <NUM>. The height-adjustable shelf <NUM> can be a wire shelf. A plurality of vertically-spaced height adjustment holes <NUM> can be provided along the side walls <NUM>, <NUM>, which allows the connection via bolts of the rail saddle <NUM> to the side walls <NUM>, <NUM>. As illustrated in <FIG>, to facilitate adjustability, each of the shelf support beam <NUM> may be seated in a pair of rail saddles <NUM> with each rail saddle <NUM> being defined by a floor, an end wall from which the pegs or dowels project, and a pair of spaced side wall members, the spaced side wall members and the floor defining a U-shaped channel to receive the shelf support beam <NUM>. The height-adjustable shelf <NUM> advantageously provides a support surface for eye-level retail display of merchandise within the OWC unit, above one or more stacks of palletized products.

The height-adjustable shelf <NUM> is provided with a wing-like curved light/air deflector <NUM>, which serves to protect and direct light from a bulb, such as an elongate LED bulb <NUM>, that is in electrical communication with a power supply for the OWC unit <NUM>. The light <NUM> may be a different light source such as, for example, electroluminescent tape, phosphor crystals, organic light emitting diodes (OLEDs), fiberglass tubing, photovoltaic cells or arrays, neon or other gas filled lights, or other lighting material. In addition to reflecting light toward the region of the OWC unit <NUM> and palletized merchandise below the height-adjustable shelf <NUM>, the wing-like curved light/air deflector <NUM> serves to direct chilled air from second and third air curtains <NUM>, <NUM> to the bottom front of the palletized product in the OWC unit <NUM>, as can be appreciated with reference to <FIG>.

With reference to <FIG>, the honeycomb diffuser assembly <NUM> is assembled in accordance with the teachings of the present disclosure. The honeycomb diffuser assembly <NUM> includes a variable-height honeycomb diffuser <NUM> and a non-variable height diffuser <NUM>. In the illustrated example, the variable-height honeycomb diffuser <NUM> is used in conjunction with one or more non-variable height diffusers or diffuser sections <NUM>, as shown in <FIG>. However, in other examples, the honeycomb diffuser assembly <NUM> may include one or more variable height diffusers and one or more non-variable height diffusers. As used herein, "variable height" refers to one or more different heights measured on a Z-coordinate axis, as shown in <FIG>. The height of the diffuser <NUM> varies along a length of the diffuser <NUM> extending on the X-coordinate axis, or in other words, between the first and second side walls <NUM>, <NUM> of the OWC unit <NUM>. The diffuser <NUM> may be sloped, staggered, corrugated, ridged, or otherwise non-planar on one or more of the top and bottom surfaces. In another example, however, the height of the diffuser may additionally, vary along a width of the diffuser <NUM> extending in the Y-coordinate axis. Additionally, as used herein, "non-variable height" refers to a uniform height measured on the Z-coordinate axis, such that the diffuser has an even, flat, or horizontal top and/or bottom surfaces.

As shown in <FIG>, the honeycomb diffuser assembly <NUM> is disposed immediately rearward of a bottom portion <NUM>, <NUM> of the first and second deflectors <NUM>, <NUM> such that an inlet <NUM>, <NUM> of each diffuser <NUM>, <NUM>, respectively, is proximally located relative to the first and second deflectors <NUM>, <NUM>. As shown in <FIG> and <FIG>, the bottom portions <NUM>, <NUM> of each deflector is staggered relative to the honeycomb assembly <NUM>. In the specific example of <FIG>, the non-variable height diffuser <NUM> is spaced from the bottom portion <NUM> of the first deflector <NUM> and adjacent to the bottom portion <NUM> of the second deflector <NUM>. As shown in <FIG> and <FIG>, the variable-height diffuser <NUM> is spaced from the bottom portion <NUM> of the second deflector <NUM>. So configured, the deflectors <NUM>, <NUM>, <NUM> direct air through channels formed between the first and second deflectors <NUM>, <NUM> and into the inlets <NUM>, <NUM> of the diffusers <NUM>, <NUM>. The diffusers <NUM>, <NUM> shape air flow forcing the air to flow through a plurality of channels <NUM> of the diffusers <NUM>, <NUM>.

As shown more clearly in <FIG>, the plurality of channels <NUM> of the variable-height diffuser <NUM> have a square or rectangular-shaped opening separated, or defined by, a plurality of walls. As shown in <FIG>, the plurality of channels <NUM> are the same or similar in both of the diffusers <NUM>, <NUM>. However, in other examples, the plurality of channels <NUM> may be circular, octagonal, or other polygonal shape with walls separating each channel of various thicknesses.

In <FIG>, the variable and non-variable height diffusers <NUM>, <NUM> are illustrated from an interior-looking-out perspective of the OWC unit <NUM>. Generally speaking, the inlet or top surface <NUM> of the variable-height diffuser <NUM> is nonplanar relative to the planar inlet <NUM> of the non-variable height diffuser <NUM>. However, at the right side of the assembly <NUM> (i.e., adjacent to the first side wall <NUM> of the OWC unit <NUM> in <FIG>), the variable and non-variable diffusers <NUM>, <NUM> initially extend along the X-axis at the same height h<NUM> measured in the Z-coordinate axis. In another example, however, the height of the first and second diffusers <NUM>, <NUM> may never match or align or they may match at the left side (i.e., adjacent the second side wall <NUM> of the OWC unit <NUM>), or between the right and left ends of the diffuser assembly <NUM>. An outlet <NUM> or bottom surface of the variable-height diffuser <NUM> is planar and, in the illustrated example, is co-planar with an outlet <NUM> (<FIG>) or bottom surface of the non-variable height diffuser <NUM>. However, in other examples, the outlet <NUM>, <NUM> of one or more of the diffusers <NUM>, <NUM> may be non-planar, such as, for example, corrugated and/or staggered. In yet further examples, the variable and non-variable diffusers <NUM>, <NUM> may be spaced from each other in a Y-coordinate direction (into the page in <FIG>), or they may be staggered relative to the Z-coordinate axis. The diffusers <NUM>, <NUM> may be separate components, or the diffusers <NUM>, <NUM> are fixedly attached to form a unitary component.

By providing a honeycomb diffuser <NUM> with a plurality of elevations and profiles across the length of the honeycomb (i.e., across the width of the OWC unit <NUM> and/or between the first and second side walls <NUM>, <NUM>), it is found that the honeycomb diffuser <NUM> is better able to attenuate the significantly variable air velocities imparted by the fans 142a, 142b, 142c, 142d, 142e of the evaporator <NUM> (<FIG>). High air velocities, on the order of <NUM> feet per minute (<NUM>,<NUM> meters per minute), are experienced in the center of the air curtain, but significantly lower air velocities are experienced at the far ends of the air curtains (on the order of only about <NUM> to about <NUM> feet per minute (about <NUM>,<NUM> to about <NUM>,<NUM> meters per minute)). The diffuser assembly <NUM> is designed to maximize air distribution across the opening <NUM> of the OWC unit <NUM> based on the airflow properties within the OWC unit <NUM>. While the variable-height honeycomb diffuser <NUM> is illustrated (such as in <FIG>) as having a first region 510a of a first height h<NUM>, a second region 510b of a second height h<NUM> shorter than the first region 510a, and a tapering third region 510c, it is recognized that the topography of the variable-height honeycomb diffuser <NUM> is not limited to that shown. Rather, the topography may be selected to provide optimal airflow uniformity within the OWC unit <NUM> to compensate for fluctuations in evaporator fan output and to achieve a desirable air flow velocity and/or pressure. By improving air velocity through the honeycomb structure of the diffuser <NUM>, it is easier, and more energy efficient, to maintain low air and product temperatures, particularly near the floor.

In <FIG> and <FIG>, the control system <NUM> is illustrated in more detail. The control system <NUM> is disposed on the roof <NUM> (hidden in <FIG>) or in the evaporator <NUM> of the OWC unit <NUM> and is coupled to control a variety of functions of the air curtain assembly <NUM> and/or the refrigeration system <NUM>. For example, the control system <NUM> operates the defrost cycle and includes at least one sensor coupled to the evaporator <NUM> and configured to capture sensor data associated with a temperature at an input <NUM> and/or inside the evaporator <NUM>, such as on a coil of the evaporator <NUM>. The control system <NUM> includes one or more processors <NUM> and a memory <NUM> that is communicatively coupled to the one or more processors <NUM> and stores executable instructions to operate the refrigeration system <NUM>. The executable instructions causes the one or more processors <NUM> to receive the sensor data captured by the one or more sensors, analyze the sensor data to identify a status or condition associated with the evaporator <NUM>, and send a signal to the evaporator <NUM> to heat or cool based on the status or condition identified.

In one example shown in <FIG>, the control system <NUM> includes a first sensor <NUM>, a second sensor <NUM>, a third sensor <NUM> and a conduit <NUM>, or temperature wire, connecting the first, second, and third sensors <NUM>, <NUM>, and <NUM> to the control system <NUM>. The temperature wire <NUM> runs through the front (i.e., the outlet side) of the evaporator <NUM> and through the back of the evaporator <NUM> (i.e., the inlet side). The first sensor <NUM> is in the return airstream before entering the coil at an input <NUM> of the evaporator <NUM>, the second sensor <NUM> is disposed on a suction line <NUM> connecting the evaporator <NUM> to the condenser <NUM>, and the third sensor <NUM> is disposed inside of the evaporator <NUM> and between the coils (i.e., where the ice clears last) of the evaporator <NUM>. So configured, the three temperature sensors <NUM>, <NUM>, <NUM> relay information about the temperatures to the control system <NUM> at various locations on or near the evaporator <NUM> to accurately determine when and how long the defrost cycle should run and to monitor the evaporator <NUM> during the defrost and cooling cycles.

Also shown in <FIG> is a backer <NUM> of the OWC unit <NUM>. The backer <NUM> provides structural support for the OWC unit <NUM> and helps channel air flow through the back duct <NUM>. The OWC unit <NUM> may include a plurality of backers <NUM> spaced apart and along the back wall <NUM> of the OWC unit <NUM>. The backers <NUM> may be positioned to channel air flow from the back duct <NUM> to feed the blower <NUM> (via the duct <NUM>), as shown in <FIG>. Together with the back wall <NUM> and the wall plates <NUM>, <NUM>, the backers <NUM> may define separate plenums formed in the back duct <NUM> to distribute air into the input <NUM> of the evaporator <NUM>. One or more of the backers <NUM> may be "Z" backers having a Z cross-section. The backers <NUM> may extend partially or entirely along a height of the OWC unit <NUM>.

Turning now to <FIG>, the OWC unit <NUM> is shown with the barrier <NUM> in a closed position (<FIG> and <FIG>) and an open position (<FIG> and <FIG>). The barrier <NUM> is a movable plate that serves to both keep air circulating through the interior space <NUM> of the OWC unit <NUM> while also protecting the product stored in the OWC unit <NUM>. In <FIG>, the barrier <NUM> sealingly engages the floor <NUM> to limit heat exchange across the opening <NUM>. As cool air from the air barrier <NUM> flows toward the ground <NUM>, the barrier <NUM> keeps the cool air within the interior space <NUM>. With the barrier <NUM> in the closed position, the opening <NUM> of the OWC unit <NUM> is large enough for a customer to comfortably reach into the OWC unit <NUM> to access the products stored in the interior space <NUM>. In <FIG>, the barrier <NUM> is lifted to an open position to permit restocking of the OWC unit <NUM> with items requiring refrigeration. In particular, the barrier <NUM> may be lifted to a height that permits a forklift to enter the OWC unit <NUM> to deliver pallets of items or remove pallets from the OWC unit <NUM>.

A first seal <NUM> is disposed along a bottom edge <NUM> of the barrier <NUM>, and a second seal <NUM> is disposed on first and second side edges <NUM>, <NUM> of the barrier <NUM>. <FIG> illustrates a magnified view of the first and second seals <NUM>, <NUM> at the bottom edge <NUM> and second side edge <NUM> of the barrier <NUM> when the barrier <NUM> is in the closed position. The first seal <NUM> is a durable seal, such as a bulb seal, having a width substantially similar to a width of the barrier <NUM>, and a length extending along the bottom edge <NUM> of the barrier <NUM>. When the barrier <NUM> is in the closed position, the seal <NUM> compresses under the weight of the barrier <NUM> and seals against the floor <NUM>. When the barrier <NUM> is in the open position, as shown in <FIG> and <FIG>, the seal <NUM> is in an uncompressed configuration. The seal <NUM> is flexible to accommodate any uneven surfaces in the floor <NUM> and may be configured to create a seal when light debris is disposed on the ground <NUM> and in the opening <NUM>. The seal <NUM> is also durable for repeated use in cold temperature environments. The seal <NUM> may be a bulb seal, a brush seal, or other suitable seal, which may be made of foam, vinyl, and rubber, and either in filled or solid configurations.

The second seal <NUM> is disposed between each of the first and second side edges <NUM>, <NUM> of the barrier <NUM> and the first and second sidewalls <NUM>, <NUM>. The second seals <NUM> allow movement of the barrier <NUM> between the open and closed positions, while sufficiently sealing a joint <NUM> between the first and second sidewalls <NUM>, <NUM> and the barrier <NUM>, thereby limiting cool air from escaping the OWC unit <NUM> at the joint <NUM>. The joint <NUM> (i.e., where the barrier <NUM> is coupled to the first and second sidewalls <NUM>, <NUM>) may be a sliding rail, pulley, or other mechanical device that slidably connects the barrier <NUM> to the first and second side walls <NUM>, <NUM>. The joint <NUM> permits an operator or automated pulley or other mechanical system to lift the barrier <NUM> from the closed position to the open position. The barrier <NUM> may remain in the open position by engaging a locking mechanism or other device.

Turning back briefly to <FIG>, an optional heating device <NUM> is shown in dashed lines. The heating device <NUM> is embedded in the OWC unit <NUM> such that the device <NUM> is disposed along the bottom of an opening header <NUM> between the first and second sidewalls <NUM>, <NUM> and a stainless steel jamb guard protecting the outer ends of the first and second sidewalls <NUM>, <NUM> and the opening header <NUM>. The heating device <NUM> is configured to elevate the temperature of the surfaces surrounding the opening <NUM> above a dew point range. The heating device <NUM> may include a heating wire that extends around the opening <NUM> of the OWC unit <NUM>, and in particularly, where heat is removed from the surfaces around the opening <NUM> by the refrigeration system <NUM>. However, in other examples, the heating wire may partially extend around the opening <NUM>, may be placed in targeted areas in segments around the opening <NUM>, may be placed only against the ends of the sidewalls <NUM>, <NUM>, or may be placed only against the door header of the roof panel <NUM>. In one example, the heating device <NUM> includes a ten watt-per-lineal-foot (<NUM> watt-per-lineal-meter) self-regulating heater, such as a Chromalox ® CPR heat trace, and may be controlled by a creep action thermostat, such as a PEPI® creep action thermostat, also embedded behind the stainless steel jamb guard trim of the opening <NUM>. The heater device <NUM> may be locally or remotely controlled, and may be operated separately from the control system <NUM> and separately from operating the barrier <NUM>.

In <FIG>, an exemplary flow diagram for operating the control system <NUM> of an OWC unit <NUM> is shown. At a first block <NUM>, sensor data is continuously (or periodically) collected by at least one sensor coupled to the evaporator <NUM>. For example, the sensors may collect temperature data at the input <NUM> and in the coil of the evaporator <NUM>. At a second block <NUM>, one or more processors <NUM> receive the sensor data captured by the sensors. At a third block <NUM>, the one or more processors <NUM> analyze the sensor data and compare the sensor data to instructions stored in the memory <NUM>. For example, a temperature captured by the at least one sensor may be compared to a temperature associated with a condition or status of the evaporator <NUM> that is stored in the memory <NUM>. The temperature captured may be compared to a threshold temperature stored in the memory <NUM>. In another example, the processor <NUM> measures a difference between the temperature at the input <NUM> of the evaporator <NUM> and the coil of the evaporator <NUM>. If the temperature measured or a temperature difference meets or exceeds a stored threshold, a status or condition associated with the evaporator <NUM> at that threshold temperature is identified and assigned at block <NUM>. Based on that identification, at block <NUM> the control system <NUM> sends a signal to the evaporator <NUM> to initiate defrost.

With respect to a defrost operation, the control system <NUM> operates according to the flow chart of <FIG> to limit ice from forming on the evaporator coil. Ice formation on the evaporator <NUM> can lower the operating efficiency of the evaporator <NUM> and may reduce the ability of the evaporator <NUM> to remove heat from the air. The defrost cycle of the control system <NUM> of the present disclosure periodically adds heat to the evaporator <NUM> to de-ice the coil in order to maintain the lowest average temperature possible inside the OWC unit <NUM>. The defrost function is based on the temperature difference between the evaporator coil and the air entering the evaporator <NUM>. The defrost function of the control system <NUM> measures the temperature difference by monitoring first, second, and third temperature sensors <NUM>, <NUM>, <NUM>. The temperature at various locations near or on the evaporator <NUM> may be monitored over a period of time. If a temperature difference between the evaporator coil and input <NUM> exceeds a temperature difference threshold stored in the memory <NUM>, a defrost cycle is initiated by sending a signal to the evaporator <NUM> to raise the temperature of the coil assembly in the evaporator <NUM>. The defrost function also monitors the coils of the evaporator <NUM> where ice clears last. Once this temperature reaches a certain threshold, then the defrost cycle may stop as that data indicates that the evaporator <NUM> is clear of ice. Additionally, the temperature taken at the suction line <NUM> connecting the evaporator <NUM> and the condenser <NUM> may indicate ice forming on the evaporator <NUM>. For example, during normal operation, heat is transferred to the refrigerant and that heat is read by the second temperature sensor <NUM>. If ice develops on the coils of the evaporator <NUM>, the second temperature sensor <NUM> will not sense any heat getting transferred to the refrigerant as that heat is blocked by the ice buildup. In this case, this temperature sensor <NUM> helps determine when to initiate the defrost cycle. Other sensor configurations and algorithms to run a defrost cycle are possible. The on-demand defrost cycle reduces the number of daily defrosts typical for a refrigeration system, and thereby saves energy. The defrost cycle also runs on an as-needed basis. The control system <NUM> may operate other functions including other sensor and sensor data. In other examples, the control system <NUM> may operate pressure sensors, humidity sensors, and auxiliary temperature sensors.

<FIG> illustrates the OWC unit <NUM> with a plurality of stacked crates or pallets <NUM> assembled in accordance with the teachings of the present disclosure. In <FIG>, a façade <NUM> extends from the roof <NUM> to hide the refrigeration and control systems <NUM>, <NUM>, and may provide an opportunity for a design or advertisement display.

<FIG> illustrates an exemplary OWC unit layout <NUM> including a plurality of OWC units <NUM> assembled in accordance with the teachings of the present disclosure. As shown in <FIG>, a plurality of OWC units <NUM> are assembled in two parallel rows in a back-to-back configuration (i.e., with the back wall <NUM> of an OWC unit <NUM> adjacent to or abutting against a back wall <NUM> of another OWC unit <NUM>) with an OWC unit <NUM> located at each end of the rows. However, other layouts and orientations are possible.

The OWC unit <NUM> of the present disclosure provides an energy-efficient solution for storing and cooling products. Firstly, the air curtain design and barrier <NUM> of the OWC unit <NUM> work together to limit heat exchange across the opening <NUM>, thereby requiring less energy to maintain cooler temperatures. The circulation provided by the air curtain assembly also more evenly distributes the cool air within the interior <NUM> of the OWC unit <NUM>. As a result, the product may be continuously surrounded by refrigerated air, and, in the case of produce, may be evenly chilled and therefore less susceptible to localized damage due to frost. For example, the air curtains <NUM>, <NUM>, <NUM> of the present disclosure are channeled and deflected to flow into different sections or spaces of the interior space <NUM> of the OWC unit <NUM>. For example, the first air curtain <NUM> flows underneath a product closer to the ground <NUM>, the second curtain <NUM> flows into a middle section of a stored product, and the third air curtain <NUM> flows across a top portion of the product.

Secondly, the refrigeration system <NUM> and control system <NUM> also help reduce energy consumption and keep costs low to run an OWC unit. The control system <NUM> may be programmed to run an on-demand defrost cycle to run the evaporator <NUM> more efficiently which consequently extends the operating life of the refrigeration system <NUM>. In addition to the energy efficiency, the refrigeration system <NUM> required for each OWC unit <NUM> is relatively small in comparison to existing cooling solutions. For example, each unit includes a small condenser <NUM>, which reduces noise and occupies less space.

The OWC unit <NUM> of the present disclosure also provides an accessible and low maintenance refrigeration storage solution. The movable barrier <NUM> facilitates stocking and restocking with product and permits easy clean-up by simply moving the barrier <NUM> to an open position. In an open position, an operator may access the crates of products with a forklift and easily clean the ground surrounding the crates. The interior space <NUM> is simple, allowing for simply stacking crates of produce for customer access. In other examples, the OWC unit <NUM> may include shelving, either built-in or provided on rollers, to store and showcase the product. When the barrier <NUM> is in the closed position, the opening <NUM> enables a customer to comfortably reach into the interior <NUM> of the OWC unit <NUM> to grab a product stored within the OWC unit <NUM>. This solution provides a more comfortable shopping experience as the customer does not need to entirely enter a refrigerated room to access the product.

Claim 1:
An accessible cooling environment comprising:
a back wall (<NUM>), an opening (<NUM>) opposite the back wall (<NUM>), a roof panel (<NUM>), first and second side walls (<NUM>, <NUM>) at least partially defining the opening (<NUM>), and an interior space (<NUM>) at least partially defined by the back wall (<NUM>), roof panel (<NUM>), and first and second side walls (<NUM>, <NUM>);
at least one fan (<NUM>) configured to circulate air through the interior space (<NUM>);
an evaporator (<NUM>) disposed inside the interior space (<NUM>);
an air curtain assembly (<NUM>) configured to form an air barrier (<NUM>) adjacent to the opening (<NUM>), the air curtain assembly (<NUM>) including one or more deflectors (<NUM>, <NUM>, <NUM>) for separating the air barrier (<NUM>) into a first air curtain (<NUM>) and a second air curtain (<NUM>); and
a diffuser (<NUM>, <NUM>, <NUM>) having a plurality of channels and a variable height as the diffuser (<NUM>, <NUM>, <NUM>) extends between the first and second side walls (<NUM>, <NUM>).