REFRIGERATOR ILLUMINATION SYSTEM

Abstract

Energy optimized reach in refrigerator overhead illumination system, for decreasing heat transfer from the environment to a reach in refrigerator, the reach in refrigerator having an opening facing upward, the illumination system including at least one refrigerator illuminator for illuminating at least one respective region of the opening, a curved opaque thermo reflective extension surrounding the at least one refrigerator illuminator, the opaque thermo reflective extension being located at a distance above the opening, the inner portion of the opaque thermo reflective extension, which points toward the opening, being made of a substantially low emissivity thermo reflective material, the inner portion reflecting infrared radiation which arrives external to the reach in refrigerator, to a region external to the reach in refrigerator, and an opaque thermo reflective extension fixation mechanism for fixing the at least one refrigerator illuminator, and the opaque thermo reflective extension above the opening.

Description

FIELD OF THE DISCLOSED TECHNIQUE

The disclosed technique relates to refrigerators in general, and to methods and systems for saving energy consumption of a top-open reach-in refrigerator, in particular.

BACKGROUND OF THE DISCLOSED TECHNIQUE

Reach-in refrigerators are open top refrigerators which are mostly used in grocery stores to keep food cold, while allowing the customer easy access to the articles stored in the reach-in refrigerator. Since the top of the reach-in refrigerator is open, heat is transferred from the surrounding, to the reach-in refrigerator, mainly by radiation. The amount of radiation emitted by a body, and the wavelength distribution thereof, is proportional to the temperature of the body, and the emissivity thereof. The total radiative flux throughout a hemisphere form a black surface of area A and absolute temperature T is given by the Stefan-Boltzman law

Q=AσT⁴   (1)

where σ is the Stefan-Boltzman constant. The net radiation balance of the body is equal to the difference between the energies received by the body, and the energies radiated by the body. For example, the Sun radiates toward the Earth, and the Earth toward the Sun. Since the absolute temperature of the Sun is much higher than that of the Earth, the energy received by the Earth is greater than the energy emitted. In case of an open-top reach-in refrigerator, the cold cavity of the reach-in refrigerator can be compared to the Earth, whose temperature is lower than that of the Sun (i.e., the cold cavity is cooler than the objects in the surrounding, which are at ambient temperature). Thus, the radiation balance of the cold cavity is positive. In order to maintain the temperature of the articles located in the reach-in refrigerator, within a desired range, more energy has to be consumed than in the case where no radiation reaches the reach-in refrigerator from the surrounding.

Methods and systems to reduce radiation heat transfer to the reach-in refrigerator, are known in the art. One such method employs a cover which can extended over the opening of the reach-in refrigerator, when the grocery store is closed, in order to prevent radiation energy flow to the reach-in refrigerator. Another such method employs a far infrared low emissivity glass plate (i.e., transparent to visible light), having various shapes, located above the reach-in refrigerator, to prevent infrared radiation from the floor, the ceiling, and the glass cover itself, which is at the ambient temperature, to enter the interior of the reach-in refrigerator The glass plate has an arched surface to reflect infrared radiation from the floor away from the freezer gondola.

U.S. Pat. No. 4,537,040 issued to Ibrahim and entitled “Automated Energy Conserving Cover for Refrigerated Cabinet Access Openings”, is directed to a system for restricting heat and moisture transfer from the ambient air, into a refrigerated display cabinet. The system employs a flexible barrier cover, which can be extended over an access opening of the refrigerated display cabinet, during non-costumer use time periods. The flexible barrier cover is part of a flexible barrier cover assembly which includes a plurality of power transmission parts, such as reels, gears, chains, and motors, to enable automatic extension of the flexible barrier cover over the access opening. The flexible barrier cover excludes the transfer of sensible heat, moisture and radiation energy inflow, from the ambient air, to the refrigerate display cabinet.

U.S. Pat. No. Re. 35,120 issued to Heaney and entitled “Display Type Refrigerator/Freezer Cabinet”, is directed to a transparent insulating structure for reducing heat transfer to a freezer compartment, having a top opening. The transparent insulating structure includes a transparent pane which is coated with an infrared reflecting visible light transmitting coating. The transparent insulating structure is located above the freezer compartment. The infrared reflecting visible light transmitting coating, reflects the infrared radiation which passes through the transparent pane, vertically through the transparent pane, without using electricity, and transmits the visible light through the transparent pane.

U.S. Pat. No. 5,421,170 issued to Sodervall, and entitled “Arrangement Relating to Refrigerator and Freezer Gondolas”, is directed to a method for reducing heat transfer to a freezer gondola, by employing a glass plate with a transparent infrared low emissivity layer. The glass plate is disposed above the freezer gondola at a height which allows access to the freezer gondola, and supported by ties from the ceiling. The glass plate has an arched surface to reflect infrared radiation from the floor away from the freezer gondola.

U.S. Pat. No. 6,558,017 issued to Saraiji et al., and entitled “Lighting System Employing Bi-Directional Optics for Illuminating Product Display Unit”, is directed to illumination of a refrigerator display cabinet. The refrigerator display unit includes a plurality of vertically spaced shelves, and a plurality of lighting units. Each of the lighting units includes a housing, and a support bracket. Each of the lighting units is mounted across a face portion of a respective vertically spaced shelf. The support bracket is attached to the housing. The support bracket conducts heat generated by the lighting unit, from the housing, to the respective vertically spaced shelf. A bottom surface of each of the vertically spaced shelves is coated with a reflective coating, to direct the light rays from the lighting unit, toward the vertically spaced shelf located below.

SUMMARY OF THE DISCLOSED TECHNIQUE

It is an object of the disclosed technique to provide a novel methods and systems for energy saving in open top refrigerators. In accordance with the disclosed technique, there is thus provided an energy optimized reach-in refrigerator overhead thermal barrier, for decreasing heat transfer from the environment to a reach-in refrigerator. The reach-in refrigerator has an opening facing upward. The thermal barrier includes a substantially transparent refrigerator cover, and a refrigerator cover fixation mechanism, for fixing the substantially transparent refrigerator cover above the opening.

The substantially transparent refrigerator cover is located at a distance above the opening. The substantially transparent refrigerator cover may be in the form of an ellipsoid. The inner portion of the substantially transparent refrigerator cover, which points toward the opening, is coated by a substantially low emissivity thermo-reflective material. The inner portion reflects infrared radiation which arrives external to the reach-in refrigerator, to a region external to the reach-in refrigerator. The substantially transparent refrigerator cover transmits visible light emitted by an overhead light source, located above the substantially transparent refrigerator cover, toward the opening.

In accordance with another aspect of the disclosed technique, there is thus provided an energy optimized reach-in refrigerator overhead thermal barrier, for decreasing heat transfer from the environment to a reach-in refrigerator. The reach-in refrigerator has an opening facing upward. The thermal barrier includes a substantially transparent refrigerator cover, and a refrigerator cover fixation mechanism for fixing the substantially transparent refrigerator cover above the opening. The substantially transparent refrigerator cover is located at a distance above the opening. The substantially transparent refrigerator cover may be in the form of an ellipsoid. The inner portion of the substantially transparent refrigerator cover, which points toward the opening, is coated by a substantially low emissivity thermo-reflective material. The inner portion reflects infrared radiation which arrives external to the reach-in refrigerator, to a region external to the reach-in refrigerator. The substantially transparent refrigerator cover transmits visible light emitted by an overhead light source, located above the substantially transparent refrigerator cover, toward the opening.

In accordance with a further aspect of the disclosed technique, there is thus provided an energy optimized reach-in refrigerator overhead illumination system, for decreasing heat transfer from the environment to a pair of reach-in refrigerators. The pair of reach-in refrigerators is located adjacent to one another. Each of the reach-in refrigerators has a respective opening facing upward. The illumination system includes a pair of refrigerator illuminators, a pair of opaque thermo-reflective extensions, and an opaque thermo-reflective extension fixation mechanism for fixing the pair of refrigerator illuminators, the pair of infrared radiation filters, and the pair of opaque thermo-reflective extensions, above the respective opening.

Each respective one of the pair of refrigerator illuminators illuminates the respective opening, and a mid-region between the pair of reach-in refrigerators, in the vicinity of a floor on which the pair of reach-in refrigerators are located. Each respective one of the pair of opaque thermo-reflective extensions surrounds the respective infrared radiation filter. The respective opaque thermo-reflective extension is located at a distance above the respective opening. Each of the opaque thermo-reflective extensions is in the form of an ellipsoid. A respective inner portion of the respective opaque thermo-reflective extension, which points toward the respective opening, is made of a substantially low emissivity thermo-reflective material. The respective inner portion reflects infrared radiation which arrives external to the respective reach-in refrigerator, and from the mid-region, to a region external to the pair of reach-in refrigerators.

In accordance with another aspect of the disclosed technique, there is thus provided an energy optimized reach-in refrigerator overhead illumination system, for decreasing heat transfer from the environment to a pair of reach-in refrigerators, located adjacent to one another. Each of the reach-in refrigerators has a respective opening facing upward. The illumination system includes a refrigerator illuminator, an infrared radiation filter, an opaque thermo-reflective extension, and an opaque thermo-reflective extension fixation mechanism for fixing the refrigerator illuminator, the infrared radiation filter, and the opaque thermo-reflective extension, above the openings.

The infrared radiation filter is located between the refrigerator illuminator and the openings. The opaque thermo-reflective extension is located at a distance above the openings. The refrigerator illuminator illuminates the openings, and a mid-region between the pair of reach-in refrigerators. The infrared radiation filter transmits visible light emitted by the refrigerator illuminator, and substantially blocks infrared radiation emitted by the refrigerator illuminator. The opaque thermo-reflective extension surrounds the infrared radiation filter.

The opaque thermo-reflective extension is in the form of an ellipsoid. An inner portion of the opaque thermo-reflective extension, which points toward the openings, is made of a substantially low emissivity thermo-reflective material. The inner portion reflects infrared radiation which arrives external to the pair of reach-in refrigerators, and from the mid-region, to a region external to the pair of reach-in refrigerators.

In accordance with a further aspect of the disclosed technique, there is thus provided a device for decreasing heat transfer from the environment to a pair of reach-in refrigerators, located adjacent to one another. Each of the reach-in refrigerators has a respective opening facing upward. The device includes an infrared outward reflector. The infrared outward reflector is located between the pair of reach-in refrigerators. The infrared outward reflector reflects infrared radiation which arrives external to the reach-in refrigerators, to a region external to the reach-in refrigerators.

In accordance with another aspect of the disclosed technique, there is thus provided a device for decreasing heat transfer from the environment to a reach-in refrigerator. The reach-in refrigerator has an opening facing upward. The device includes a dehumidifier. The dehumidifier blows substantially dehumidified air through an outlet at a first side-panel of the reach-in refrigerator, into the opening, to form a substantially dehumidified air curtain above the opening.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosed technique will be understood and appreciated more fully from the following detailed description taken in conjunction with the drawings in which:

FIG. 1 is a schematic illustration of a system in perspective, for reducing the thermal load on a top-open reach-in refrigerator, constructed and operative in accordance with an embodiment of the disclosed technique;

FIG. 2 is a schematic illustration of a cross section of the refrigerator cover of the system of FIG. 1;

FIG. 3 is a schematic illustration of an illumination module of the refrigerator cover of FIG. 1;

FIG. 4A is a schematic illustration of a refrigerator, constructed and operative according to another embodiment of the disclosed technique;

FIG. 4B is a schematic illustration of a refrigerator, constructed and operative according to a further embodiment of the disclosed technique;

FIG. 5 is a schematic illustration of a system for reducing the thermal load on a pair of top-open reach-in refrigerators, constructed and operative in accordance with a further embodiment of the disclosed technique;

FIG. 6 is a schematic illustration of a refrigerator cover, which includes an opaque side-panel, whose height is substantially equal to the depth of the refrigerator cover, constructed and operative according to another embodiment of the disclosed technique;

FIG. 7 is a schematic illustration of a refrigerator cover, which includes an opaque side-panel, which covers substantially the entire opening at a side of the refrigerator, between the refrigerator cover and the top of the refrigerator, constructed and operative according to a further embodiment of the disclosed technique;

FIG. 8 is a schematic illustration of a refrigerator cover, which includes a side panel whose first portion is opaque and a second portion thereof is transparent and impervious to infrared radiation, constructed and operative according to another embodiment of the disclosed technique;

FIG. 9A is a schematic illustration of a retroreflector, to prevent radiation originating externally to a pair of refrigerators similar to the refrigerator of FIG. 1, to reach the opening of the refrigerators, constructed and operative according to a further embodiment of the disclosed technique;

FIG. 9B is a schematic illustration of a detail of the retroreflector of FIG. 9A;

FIG. 9C is a schematic illustration in perspective, of the retroreflector of FIG. 9A;

FIG. 10 is a schematic illustration of a refrigerator cover, constructed and operative according to another embodiment of the disclosed technique;

FIG. 11 is a schematic illustration of an assembly of the air filter, heat conveyor, housing, refrigerator illuminator, infrared radiation filter, and the optical assembly of the refrigerator cover of FIG. 3;

FIG. 12 is a schematic illustration in perspective, of the parts which make up one of the modules, of the refrigerator cover of FIG. 1;

FIG. 13 is a schematic illustration in perspective, of an assembly of a section of the refrigerator cover of FIG. 1;

FIG. 14 is a schematic illustration in perspective, of a bottom view of an assembly, of a refrigerator cover similar to the refrigerator cover of FIG. 1, constructed and operative according to a further embodiment of the disclosed technique;

FIG. 15 is a schematic illustration in perspective, of a top view of the refrigerator cover of FIG. 14;

FIG. 16 is a schematic illustration in perspective, of the assembly of the parts of the refrigerator cover of FIG. 14;

FIG. 17 is a schematic illustration of a system to deposit metal on a transparent sheet, which afterwards is formed into the shape of the refrigerator cover of FIG. 10, constructed and operative according to another embodiment of the disclosed technique;

FIG. 18 is a schematic illustration of a system for reducing the thermal load on a top-open reach-in refrigerator, constructed and operative according to a further embodiment of the disclosed technique;

FIG. 19A is a thermal analysis of a pair of refrigerators with no refrigerator cover above the refrigerators;

FIG. 19B is a thermal analysis of a pair of refrigerators with a refrigerator cover located at a distance above, having a geometry of a portion of a cylinder, wherein the inner surfaces of the side panels of the refrigerators of FIG. 4A, are coated with a substantially low emissivity thermo-reflective material ( in this example it is 3%); and

FIG. 19C is a thermal analysis of a pair of refrigerators with a refrigerator cover located at a distance above, having a geometry of an ellipsoid, wherein the inner surfaces of the side panels of the refrigerators of FIG. 4A, are coated with a substantially low emissivity thermo-reflective material.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The disclosed technique overcomes the disadvantages of the prior art by providing an open-top reach-in refrigerator illuminator, with reduced infrared radiation toward the reach-in refrigerator, and with an opaque thermo-reflective extension which covers the entire opening of the open-top reach-in refrigerator. The opaque thermo-reflective extension reflects a wide spectrum of radiation, including visible light and infrared radiation which arrives from a building envelope, or the opaque thermo-reflective extension itself, to a non-insulated open-top cavity of the refrigerator. Thus, the heat transfer from the surrounding to the refrigerator is reduced, and as a result, the thermal load on a heat pump of the refrigerator, to maintain the refrigerator at a selected temperature, is reduced, thereby saving energy.

The opaque material of the opaque thermo-reflective extension, blocks most of the radiation from wide spectrum sources, which is emitted by a building envelop ceiling, walls, windows, and artificial light, thereby reducing the thermal load furthermore. This blocking action is due to the substantially low emissivity of the inner surface of opaque thermo-reflective extension, thereby shifting the radiation balance of the cavity of the reach-in refrigerator, toward a positive value. Additionally, the illuminator includes a heat conveyor and a infrared radiation filter. The heat conveyor conveys the heat dissipated by the illuminator, to the surrounding above the opaque thermo-reflective extension, and the infrared radiation filter blocks the light within the thermal region of the spectrum (i.e., far infrared), which is emitted by the illuminator, and transmits the light in the visible light. The term “emissivity” (also known as “emitance”) herein below, refers to the total radiating power of a real surface, to that of a black surface, at the same temperature.

Reference is now made to FIGS. 1, 2, and 3. FIG. 1 is a schematic illustration of a system in perspective, generally referenced 100, for reducing the thermal load on a top-open reach-in refrigerator, constructed and operative in accordance with an embodiment of the disclosed technique. FIG. 2 is a schematic illustration of a cross section of the refrigerator cover of the system of FIG. 1. FIG. 3 is a schematic illustration of an illumination module of the refrigerator cover of FIG. 1.

System 100 (i.e., energy optimized reach-in refrigerator overhead illumination system), includes a refrigerator cover 102 (i.e., opaque thermo-reflective extension), a refrigerator illuminator 104, a heat conveyor 106, a infrared radiation filter 108, and a fixation mechanism 110 (i.e., opaque thermo-reflective extension fixation mechanism). Refrigerator illuminator 104 is a light source which emits visible light, as well as infrared radiation. Refrigerator illuminator 104 can be an incandescent lamp, fluorescent lamp, mercury vapor lamp, neon lamp, metal halide lamp, high pressure sodium lamp, light emitting diode (LED) light source, tungsten halogen light source, and the like.

Refrigerator cover 102 is made of a substantially low density material (e.g., foamed polymer, polystyrene, polyolefin, polycarbonate, polyethylene, polypropylene, air containing structure, such as thin walled polycarbonate, acrylic plates, or thin wall plates of polycarbonate and acrylic).

Refrigerator cover 102 is made of an opaque material, which includes a metal foil layer, or a metalized polymer layer. Thus, refrigerator cover 102 blocks light in substantially all wavelengths (i.e., visible as well as invisible spectrum), emitted by a light source 112 located above refrigerator cover 102.

Refrigerator cover 102 is in a concave shape, such as an ellipsoid, and the like. The four conic surfaces (i.e., sphere, paraboloid, ellipsoid, and hyperboloid) are described by Equation (2), as known in the art

$\begin{array}{cc}Z=\frac{Y^2/R}{1+\sqrt{\left(K+1\right)Y^2/R^2}}\mathrm{where}& \left(2\right)\\ R=\frac{a^2}{b}\mathrm{and}& \left(3\right)\\ K=\frac{R}{b}-1& \left(4\right)\end{array}$

In case of an ellipsoid, −√<b<∞, 0<a<∞, −∞<R<∞, and 0<K<−1. The constant K herein below, is referred as the “conic constant”.

The center of the concave geometry is located midway between the focal points of the concave geometry. In case of a single reach-in refrigerator, this center is located at the center of a top plane of the opening of the reach-in refrigerator. In case of a pair of reach-in refrigerators, the center is located at the center of a top plane, defining the openings of both reach-in refrigerators, and the focal points (in case of an ellipsoid) are located at the top plane.

An inner surface 114 of refrigerator cover 102 is made of an opaque reflective material, having a substantially low emissivity. For example, inner surface 114 can be coated with a reflective material (e.g., metallic foil, metalized foil, electrolytic coating, such as Chrome, and the like). Hence, depending on the type of the curvature of refrigerator cover 102, inner surface 114 can reflect a far infrared ray, from a relatively hot surface of the floor, in a selected direction, external to opening 116. It is noted that since the emissivity of inner surface 114 is substantially low, the infrared radiation emitted by inner surface 114, is less than in the case of an inner surface having a higher emissivity.

Heat conveyor 106 is a device which transfers heat. Heat conveyor 106 is an active heat transfer device, such as fan, thermoelectric cooler (e.g., Josephson junction, Peltier), heat pump operating according to a heat cycle (e.g., Sterling), and the like. Alternatively, heat conveyor 106 can be a passive heat transfer device, such as heat sink, and the like. Hence, heat conveyor 106 can transfer heat by convection, conduction, radiation, or a combination thereof.

Infrared radiation filter 108 is an optical element which substantially blocks light within the far infrared region of the spectrum, and substantially transmits visible light within the rest of the spectrum. Fixation mechanism 110 is a device which supports refrigerator cover 102, refrigerator illuminator 104, heat conveyor 106, and infrared radiation filter 108, above an opening 116 of a refrigerator 118 (i.e., open-top reach-in refrigerator). In the example set forth in FIG. 1, fixation mechanism 110 is in the form of a plurality of guy wires 120, coupled with refrigerator cover 102 and a ceiling 122. In this case, refrigerator cover 102, refrigerator illuminator 104, heat conveyor 106, and infrared radiation filter 108, hang from ceiling 122 by guy wires 120 by the force of gravity. Alternatively, fixation mechanism 110 can be in the form of a plurality of posts 124, coupled with refrigerator cover 102 and with refrigerator 118. In this case, refrigerator 118 supports the weight of refrigerator cover 102, refrigerator illuminator 104, heat conveyor 106, and infrared radiation filter 108.

Refrigerator illuminator 104 is coupled with refrigerator cover 102 along a longitudinal axis 126 of refrigerator cover 102, such that refrigerator illuminator 104 illuminates opening 116. Infrared radiation filter 108 is coupled with refrigerator cover 102, and located between refrigerator illuminator 104 and opening 116. Infrared radiation filter 108 blocks the light emitted by refrigerator illuminator 104, within the infrared range of the spectrum, thereby preventing the infrared radiation to reach opening 116. In this manner, infrared radiation filter 108 reduces the thermal load on refrigerator 118. Infrared radiation filter 108 transmits the visible light to opening 116, within the rest of the spectrum.

Heat conveyor 106 is coupled with refrigerator cover 102. Heat conveyor 106 transfers the heat dissipated by refrigerator illuminator 104, away from opening 116. Hence, heat conveyor 106 reduces the thermal load on refrigerator 118.

Refrigerator illuminator 104, heat conveyor 106, and infrared radiation filter 108 can be coupled with a housing 128, and housing 128 in turn, can be coupled with refrigerator cover 102. In the example set forth in FIG. 3, heat conveyor 106 is in the form of an electric fan, and housing 128 includes air chambers 130 and 132, and a plurality of air filters 134 and 136. Air chamber 130 is confined by heat conveyor 106 and an illuminator bracket 138 of refrigerator illuminator 104. Illuminator bracket 138 is provided with a plurality of perforations (not shown). Air chamber 132 is confined by illuminator bracket 138 and infrared radiation filter 108. Air filters 134 are located on a periphery of air chamber 130. Air filters 136 are located on a periphery of air chamber 132. The electric fan sucks the air from the surrounding, out to a region above refrigerator cover 102, through air filters 134 and 136, air chambers 130 and 132, and the perforations of illuminator bracket 138. In this manner, the electric fan carries the heat generated by refrigerator illuminator 104, to a region external to refrigerator 118 and opening 116, thereby reducing the heat load on refrigerator 118.

With reference to FIG. 2, inner surface 114 reflects infrared rays 140A which is emitted by a floor 142 on which refrigerator 118 rests, as light rays 140B, to a region external to refrigerator 118. This is provided by selecting a concave geometry having a suitable conic constant, as described herein above. Due to the low emissivity of the thermo-reflective material of inner surface 114, and the selected value of the conic constant of inner surface 114, inner surface 114 prevents infrared rays 140A to enter refrigerator 118 through opening 116, thereby reducing the thermal load on refrigerator 118. It is noted that the infrared rays can originate from the ceiling, and the walls, including windows (not shown), as well as from the floor, and inner surface 114, whose surface temperature is substantially equal to the ambient temperature, and thus much greater than that of the articles present within refrigerator 118.

Refrigerator cover 102 blocks rays 148 emitted by light source 112, and prevents light rays 148 to enter opening 116. The wavelength of light rays 148 can be within the visible range of the spectrum, as well as the invisible range (e.g., far infrared). In this manner, refrigerator cover 102 reduces the heat load on refrigerator 118. Due to the substantially low emissivity of the reflective material of inner surface 114, substantially no infrared radiation is emitted by refrigerator cover 102, which would otherwise enter opening 116.

Refrigerator cover 102 is located at such a distance above opening 116, that a user 146, can have access to articles 150, stored within refrigerator 118. System 100 can further include an optical assembly 144. Optical assembly 144 includes one or more optical elements (not shown), such as lens, collimator, light filter, polarizer, and the like. Optical assembly 144 is located between infrared radiation filter 108, and opening 116. Optical assembly 144 can impart selected optical properties to the light transmitted by infrared radiation filter 108, such as direction, color, polarization, and the like. For example, optical assembly 144 can focus the light on a selected region of opening 116.

Refrigerator cover 102 can further include an air filter (not shown) coupled with heat conveyor 106. In case heat conveyor 106 includes a fan to blow out the warm air due to the heat generated by refrigerator illuminator 104, the air filter filters the air that the fan blows out.

According to another aspect of the disclosed technique, the side panels of the refrigerator are coated with a reflective material, whose emissivity is substantially small, and within the far infrared range of the spectrum. This reflective material, which emits substantially small amounts of infrared radiation, reflects the infrared radiation which reaches the refrigerator from the surrounding, to a region external to the refrigerator, thereby reducing the thermal load on the refrigerator, and saving energy. In case no side panel is employed, the infrared radiation from the side of the refrigerator, which is at the ambient temperature, or above the temperature of the opening of the refrigerator, would reach the inner surface of the refrigerator cover, and would be reflected by the inner surface toward the opening of the refrigerator. Furthermore, since the temperature of the bodies (not shown) at the side of the reach-in refrigerator varies within a substantially large range, these bodies would absorb the infrared radiation from other bodies present in the confinement, and emit the infrared radiation toward the inner surface of the refrigerator cover, as well as the opening of the reach-in refrigerator, and the cold portions of the reach-in refrigerator, and thus increase the thermal load on a heat pump (not shown), of the reach-in refrigerator. It is noted that in case the thermal load on a heat pump (not shown) of refrigerator 118, due to the infrared radiation emitted by refrigerator illuminator 104 is not large, infrared radiation filter 108 can be eliminated from system 100.

Reference is now made to FIGS. 4A, and 4B. FIG. 4A is a schematic illustration of a refrigerator, generally referenced 160, constructed and operative according to another embodiment of the disclosed technique. FIG. 4B is a schematic illustration of a refrigerator, generally referenced 190, constructed and operative according to a further embodiment of the disclosed technique.

With reference to FIG. 4A, each of a top surface 162 and an inner surface 164 of a side panel 166 of refrigerator 160, is coated with a reflective material. The reflective material reflects the infrared rays (not shown), which are received by reach-in refrigerator 160 from the surrounding, to a region external to refrigerator 160, thereby reducing the thermal load on refrigerator 160. The reflective material has a substantially low emissivity, and is made for example, from a multilayer laminate containing aluminum or a metalized foil, and the like. The low emissivity of the reflective material prevents most of far infrared radiation to reach the inner surface of the refrigerator cover, For example, the reflective material can reflect the infrared rays to a reflective inner surface 168 of a refrigerator cover 170, which is fixed above an opening 172 of refrigerator 160. Reflective inner surface 168 in turn reflects the infrared ray, toward a region external to opening 172, thereby reducing the thermal load on refrigerator 160, and saving energy. Reflective surface 168 also jas low emissivity and thus the thermal radiation from it is substantially reduced and thus less infrared energy enters the refrigerator opening 160 Additionally, since the emissivity of the reflective material of top surface 162 is substantially low, top surface 162 reflects only a substantially small amount of the infrared radiation toward the inner surface of the refrigerator cover, which would otherwise be reflected back to opening 172, by the inner surface of the refrigerator cover. The reflective material coating of each of side panels 164 and 166 is made of a low-emissivity material similar to the reflective material of inner surface 114, as described herein above in connection with FIG. 2. Side panel 164 includes a plurality of louvers to allow the cool air to flow toward an inner portion (not shown) of reach-in refrigerator 160.

With reference to FIG. 4B, refrigerator 190 includes side panels 192, and 194. Side panel 192 includes a top surface 196 and an inner surface 198. Each of top surface 196 and inner surface 198 are coated with a reflective material. The reflective material of each of top surface 196 and inner surface 198, reflects infrared rays (not shown) which reach refrigerator 190 from the surrounding (e.g., the inner surface of the refrigerator cover, the ceiling, the walls, the windows, and the floor), to a region external to refrigerator 190, thereby reducing the thermal load on refrigerator 190.

Side panel 194 includes a top surface 200, an outer glass layer 202, an inner glass layer 204, and an infrared radiation filter 206. Top surface 200 is coated with a reflective material. Infrared radiation filter 206 is similar to infrared radiation filter 108, as described herein above in connection with FIG. 3. A space 208 between outer glass layer 202 and inner glass layer 204, is evacuated and at a pressure below the atmospheric pressure (i.e., vacuum), thereby thermally insulating side panel 194 from the environment. Infrared radiation filter 206 transmits visible light toward an inner region 210 of refrigerator 190, and blocks infrared radiation, thereby reducing the thermal load on refrigerator 190.

Reference is now made to FIG. 5, which is a schematic illustration of a system generally referenced 250, for reducing the thermal load on a pair of top-open reach-in refrigerators, constructed and operative in accordance with a further embodiment of the disclosed technique. System 250 includes a pair of refrigerator covers 252 and 254, a pair of refrigerator illuminators 256 and 258, a pair of heat conveyors (not shown), a pair of infrared radiation filters (not shown), a pair of optical assemblies (not shown), and a fixation mechanism 260. Each of refrigerator covers 252 and 254 is similar to refrigerator cover 102 (FIG. 2), as described herein above. Each of refrigerator illuminators 256 and 258 is similar to refrigerator illuminator 104 (FIG. 3), as described herein above. Each pair of the heat conveyors, the infrared radiation filters, and the optical assemblies, is similar to heat conveyor 106 (FIG. 3), infrared radiation filter 108, and optical assembly 144, respectively, as described herein above. Alternatively, a system similar to system 250 can include a single refrigerator cover covering both of the pair of reach-in refrigerators.

In the example set forth in FIG. 5, fixation mechanism 260 includes a plurality of guy wires and mechanical fastening parts, coupled between a ceiling 272 of a confinement, in which a pair of top-open reach-in refrigerators 262 and 264 are located, and refrigerator covers 252 and 254. Each of refrigerator covers 252 and 254 are suspended from the ceiling, with the aid of fixation mechanism 260. Refrigerator illuminator 256, one of the pair of heat conveyors, one of the pair of the infrared radiation filters, and one of the pair of optical assemblies, are coupled with refrigerator cover 252. Refrigerator illuminator 258, the other pair of the heat conveyors, the other pair of the infrared radiation filters, and the other pair of the optical assemblies, are coupled with refrigerator cover 254. Refrigerator covers 252 and 254 are located above openings 266 and 268, of refrigerators 262 and 264, respectively.

One of the pair of the optical assemblies directs the light emitted by refrigerator illuminator 256 toward opening 266 of refrigerator 262. The other pair of the optical assemblies directs the light emitted by refrigerator illuminator 258 toward opening 268 of refrigerator 264. Each of the pair of the optical assemblies are constructed such that the light emitted by each of refrigerator illuminators 256 and 258, illuminates a region 270 located between the pair of refrigerators 262 and 264, which in case of a pair of refrigerators covers devoid of refrigerator illuminators, would be a substantially dark region. Furthermore, each of the pair of refrigerator covers 252 and 254, reflects the infrared radiation arriving from region 270, to a region outside openings 266 and 268, respectively, thereby reducing the thermal load on refrigerators 262 and 264, respectively.

According to another aspect of the disclosed technique, the refrigerator cover includes a side panel to prevent infrared radiation to reach the opening of the refrigerator. The side panel is made of an opaque material, and its height is substantially equal to a depth of the refrigerator cover. This side panel blocks radiation, within the visible range as well as the invisible range of the spectrum, and prevents radiation to enter the opening of the refrigerator. The emissivity of an inner surface of the side panel (i.e., the surface which faces the opening of the refrigerator), is substantially low. Thus, substantially no infrared radiation from the side of the refrigerator, enters the opening of the refrigerator.

Alternatively, the side panel extends from the refrigerator cover, to a top of the refrigerator, and covers the entire opening of the refrigerator, at a side thereof. This side panel is also made of an opaque material, which blocks radiation in substantially all ranges of the spectrum.

Further alternatively, a first portion of the side panel is made of an opaque material, and a second portion thereof is made of a transparent material which blocks infrared radiation. Both sides of the first portion is coated with a substantially low emissivity thermo-reflective material, to substantially block infrared radiation. The height of the side panel along the first portion, is substantially equal to the depth of the refrigerator cover. The height of the side panel along the second portion, is substantially equal to the distance between the lower edge of the refrigerator and the top of the refrigerator. The first portion blocks radiation entirely, while the second portion transmits visible light which originates from the surrounding as well as from the refrigerator illuminator, and blocks infrared radiation which originates from the surrounding. Hence, a user can view the articles located within the refrigerator through the second portion.

Reference is now made to FIGS. 6, 7, and 8. FIG. 6 is a schematic illustration of a refrigerator cover, generally referenced 300, which includes an opaque side-panel, whose height is substantially equal to the depth of the refrigerator cover, constructed and operative according to another embodiment of the disclosed technique. FIG. 7 is a schematic illustration of a refrigerator cover, generally referenced 350, which includes an opaque side-panel, which covers substantially the entire opening at a side of the refrigerator, between the refrigerator cover and the top of the refrigerator, constructed and operative according to a further embodiment of the disclosed technique. FIG. 8 is a schematic illustration of a refrigerator cover, generally referenced 400, which includes a side panel whose first portion is opaque and a second portion thereof is transparent and impervious to infrared radiation, constructed and operative according to another embodiment of the disclosed technique.

With reference to FIG. 6, refrigerator cover 300 includes an opaque side-panel 302, and a plurality of refrigerator illuminators 304 and 306. Opaque side-panel 302 covers a concave surface (not shown) of refrigerator cover 300, along a substantially flat surface substantially perpendicular to a longitudinal axis of the refrigerator, such as longitudinal axis 126 (FIG. 1). The substantially flat surface is located at an extreme side of refrigerator cover 300. An inner surface 316 of opaque side-panel 302 includes a substantially low emissivity thermo-reflective material. Therefore, opaque side-panel 302 blocks rays 308 which originate from the surrounding. Due to the presence of this substantially low emissivity thermo-reflective material, opaque side-panel 302 emits a substantially amount of infrared radiation. In this manner, opaque side-panel 302 prevents rays 308, which can be infrared rays as well as visible light rays, to reach an opening 310 of a refrigerator 312. Since opaque side-panel 302 covers only the concave surface of refrigerator cover 300, light emitted by refrigerator illuminators 304 and 306, can illuminate a region 314 at a side of refrigerator 312. Furthermore, the user can have access to refrigerator 312, from region 314.

With reference to FIG. 7, refrigerator cover 350 includes an opaque side-panel 352, and a plurality of refrigerator illuminators 354 and 356. Opaque side-panel 352 substantially entirely covers a region 358 at a side of a refrigerator 360 (i.e., opaque side-panel 352 extends from an inner surface 362 of refrigerator cover 350, to a top edge 364 of refrigerator 360, in a direction substantially perpendicular to a floor 366 on which refrigerator 360 rests, and along a substantially flat surface). An inner surface (not shown) of opaque side-panel 352, facing an opening 368 of refrigerator 360, includes a substantially low emissivity thermo-reflective material. Therefore, opaque side-panel 352 blocks radiation in substantially the entire spectrum (i.e., prevents visible light as well as infrared radiation to reach opening 368). Opaque-side panel 352 furthermore blocks visible light emitted by refrigerator illuminators 354 and 356.

With reference to FIG. 8, refrigerator cover 400 includes a side panel 402 and a plurality of refrigerator illuminators 404 and 406. Side panel 402 covers substantially entirely, a region 408 at a side of a refrigerator 410, as described herein above in connection with opaque side-panel 352 (FIG. 7). A first portion 412 of side panel 402, covers a concave surface (not shown) of refrigerator cover 400, as described herein above in connection with opaque side-panel 302 (FIG. 6). A second portion 414 of side panel 402 extends from a bottom edge 416 of first portion 412, toward a top edge 418 of refrigerator 410.

First portion 412 is made of an opaque material, thereby blocking radiation within substantially the entire spectrum (i.e., visible light as well as infrared radiation). Second portion 414 is made of a transparent material which transmits visible light, and blocks infrared radiation. Hence, second portion 414 transmits visible light which originates from the surrounding as well as from refrigerator illuminators 404 and 406, while blocking infrared radiation which originates from the surrounding. Visible light emitted by refrigerator illuminators 404 and 406 can illuminate region 408, and furthermore visible light originating from the surrounding can illuminate an opening 420 of refrigerator 410. Furthermore, second portion 414 prevents infrared radiation which originates from the surrounding, to reach opening 420.

Reference is now made to FIGS. 9A, 9B, and 9C. FIG. 9A is a schematic illustration of a retroreflector, generally referenced 450, to prevent radiation originating externally to a pair of refrigerators similar to the refrigerator of FIG. 1, to reach the opening of the refrigerators, constructed and operative according to a further embodiment of the disclosed technique. FIG. 9B is a schematic illustration of a detail of the retroreflector of FIG. 9A. FIG. 9C is a schematic illustration in perspective, of the retroreflector of FIG. 9A.

A pair of refrigerators 452 and 454 are situated side by side. A longitudinal edge 456 of refrigerator 452 makes contact with a longitudinal edge 458 of refrigerator 454, thereby forming a mutual longitudinal edge 460. Retroreflector 450 (i.e., infrared outward reflector) is coupled with mutual longitudinal edge 460. Retroreflector 450 (FIG. 9C) is in the form of a prism whose base is in form of a triangle referenced 462. A base of triangle 462 is referenced 464, and the two sides thereof are referenced 466 and 468. The two surfaces of retroreflector 450 along sides 466 and 468, are referenced 470 and 472, respectively. A plurality of longitudinal saw-toothed indentations 474 (FIG. 9B), are formed on each of surfaces 470 and 472. A cross section of each of longitudinal saw-toothed indentations 474, is in form of equal sided triangle. Longitudinal saw-toothed indentations 474 impart retroreflective properties to retroreflector 450.

A ray 476 (FIG. 9B) which strikes a first surface 478 of a longitudinal saw-toothed indentation 474, reflects from a second surface 480 of longitudinal saw-toothed indentation 474, as a ray 482. Due to the geometry of longitudinal saw-toothed indentation 474, a direction of ray 482 is substantially opposite to that of ray 476 (i.e., ray 482 travels toward a source of ray 476, thereby indicating that retroreflector 450 returns the radiations toward the source). Hence, retroreflector 450 returns radiations (i.e., visible light as well as infrared radiation), toward the source, thereby preventing infrared radiation to reach openings 484 and 486 of refrigerators 452 and 454, respectively, and reducing the thermal load on refrigerators 452 and 454.

Alternatively, saw-toothed indentations 474 can be made of a transparent material, and a plurality of visible images 488 can be placed behind indentations 474, such that each visible image 488 is visible to user 146 who accesses each of refrigerators 452 and 454. The medium presenting each of visible images 488 can be made of an ink bearing medium (e.g., paper, polymeric sheet), dynamic digital display (e.g., e-reader—dynamic digital display which updates the visible image by accessing a database via a network, radio frequency identification device—RFID), static digital display (e.g., organic light emitting diode—OLED, liquid crystal display—LCD). Each of visible images 488 can be an advertisement, include information related to a commodity, such as the price, ingredients, date of manufacture, last date for use, and the like.

It is noted that the infrared outward reflector can be in the form of an elongated concave surface. Alternatively, the infrared outward reflector can include a plurality of corner retroreflectors. It is further noted that each of the surfaces of the infrared outward reflector as described herein above, can be made of a transparent material, to enable the user to view an image located behind the surface.

Reference is now made to FIG. 10, which is a schematic illustration of a refrigerator cover, generally referenced 550, constructed and operative according to another embodiment of the disclosed technique. Refrigerator cover 550 is located on top of openings 552 and 554 of refrigerators 556 and 558, respectively. A light source 560 is located above refrigerator cover 550. Refrigerator cover 550 is made of a transparent material, whose inner surface 562 is coated with a substantially low emissivity thermo-reflective material. This substantially low emissivity thermo-reflective material can be applied to inner surface 562, for example in a vacuum web coating process, as described herein below in connection with FIG. 17.

Due to the transparency of refrigerator cover 550, refrigerator cover 550 transmits the visible light emitted by light source 560, toward openings 552 and 554. Due to the substantially low emissivity thermo-reflective material, refrigerator cover 550 blocks the infrared radiation emitted by light source 560, as well as that emitted by objects from various regions of the confinement in which refrigerators 556 and 558 are located (e.g., the floor, walls, ceiling). Reference is now made to FIG. 11, which is a schematic illustration of an assembly, generally referenced 600, of the air filter, heat conveyor, housing, refrigerator illuminator, infrared radiation filter, and the optical assembly of the refrigerator cover of FIG. 3. Assembly 600 includes an air filter 602, a fan 604, a housing 606, a refrigerator illuminator 608, a infrared radiation filter 610, and an optical assembly 611. Fan 604, housing 606, refrigerator illuminator 608, infrared radiation filter 610, and optical assembly 611 are similar to the fan, housing 128, refrigerator illuminator 104, infrared radiation filter 108, and optical assembly 144, respectively, as described herein above in connection with FIGS. 2, and 3. Air filter 602, fan 604, refrigerator illuminator 608, infrared radiation filter 610, and optical assembly 611, are coupled with housing 606. Infrared radiation filter 610 is located between refrigerator illuminator 608 and optical assembly 611.

Reference is now made to FIGS. 12, and 13. FIG. 12 is a schematic illustration in perspective, of the parts which make up one of the modules, generally referenced 650, of the refrigerator cover of FIG. 1. FIG. 13 is a schematic illustration in perspective, of an assembly of a section of the refrigerator cover of FIG. 1, generally referenced 680.

Module 650 includes a concave shaped part 652, and a reflective material 654. The mechanical properties of concave shaped part 652, and reflective material 654 are similar to that of refrigerator cover 102 (FIG. 1), and the reflective material, respectively, as described herein above. Concave shaped part 652 is manufactured by injection molding, casting, cold molding, compression molding, insert molding, liquid injection molding, multi-shot molding, reaction injection molding, structural foam molding, transfer molding, vacuum forming, stereolithography, and the like. Concave shaped part 652 is coated with reflective material 654, after manufacture of concave shaped part 652. Alternatively, reflective material 654 is integrated with concave shaped part 652 during the manufacturing process of concave shaped part 652. Concave shaped part 652 includes a plurality of ribs 656, which impart mechanical strength to concave shaped part 652.

With reference to FIG. 13, section 680 includes a plurality of modules 682 and 684, a refrigerator illuminator 686, a heat conveyor 688, a infrared radiation filter 690, and an optical assembly 692. Each of modules 682 and 684 is similar to module 650. Refrigerator illuminator 686, heat conveyor 688, infrared radiation filter 690, and optical assembly 692 are similar to refrigerator illuminator 104, heat conveyor 106, infrared radiation filter 108, and optical assembly 144, respectively, as described herein above in connection with FIG. 3. Section 680 is constructed by coupling together modules 682 and 684, at edges 694 and 696 of modules 682 and 684, respectively. This coupling is performed by employing for example, a plurality of snap fits (not shown), mechanical fasteners (not shown—e.g., threaded fasteners, rivets), adhesive, welding process, and the like.

Modules 682 and 684 include cavities 698 and 700, respectively, at edges 694 and 696 thereof, respectively, in order to embody the assembly of refrigerator illuminator 686, heat conveyor 688, infrared radiation filter 690, and optical assembly 692, there between. Refrigerator cover 102 can be constructed by coupling together a plurality of sections similar to section 680, at a plurality of transversal edges (not shown) of a plurality of modules similar to modules 682 and 684, wherein the transversal edges are substantially perpendicular to longitudinal axis 126 (FIG. 1).

Reference is now made to FIGS. 14,15, and 16. FIG. 14 is a schematic illustration in perspective, of a bottom view of an assembly, generally referenced 720, of a refrigerator cover similar to the refrigerator cover of FIG. 1, constructed and operative according to a further embodiment of the disclosed technique. FIG. 15 is a schematic illustration in perspective, of a top view of the refrigerator cover of FIG. 14. FIG. 16 is a schematic illustration in perspective, of the assembly of the parts of the refrigerator cover of FIG. 14.

Assembly 720 includes a refrigerator cover 722, a refrigerator illuminator 724, an illuminator reflector 726, reflective materials 728 and 730, and a infrared radiation filter 732. Refrigerator cover 722, refrigerator illuminator 724, reflective materials 728 and 730, and infrared radiation filter 732, are similar to refrigerator cover 102, refrigerator illuminator 104, the reflective material, and infrared radiation filter 108, respectively, as described herein above in connection with FIGS. 1, 2, and 3.

Refrigerator illuminator 724, illuminator reflector 726, and infrared radiation filter 732 are coupled with refrigerator cover 722. In the example illustrated in FIGS. 14, 15, and 16, refrigerator illuminator 724 has a longitudinal geometry construction. Refrigerator illuminator 724 is located along a median longitudinal axis 736 of refrigerator cover 722. Illuminator reflector 726 is located above refrigerator illuminator 724. Reflective materials 728 and 730 cover an inner surface 734 (FIG. 14) of refrigerator cover 722. Reflective material 728 is located at a first side of refrigerator illuminator 724 and reflective material 730 is located at a second side of refrigerator illuminator 724.

Illuminator reflector 726 is located on top of refrigerator illuminator 724, in order to reflect the light emitted by refrigerator illuminator 724 toward an opening (not shown), of a refrigerator (not shown), located beneath the refrigerator cover. Infrared radiation filter 732 is located below refrigerator illuminator 724, to prevent infrared radiation produced by refrigerator illuminator 724, to reach the opening of the refrigerator.

Reference is now made to FIG. 17, which is a schematic illustration of a system generally referenced 750, to deposit metal on a transparent sheet, which afterwards is formed into the shape of the refrigerator cover of FIG. 10, constructed and operative according to another embodiment of the disclosed technique. System 750 includes a drum 752, a vacuum web coater 754, and a transparent polymer sheet 756. Transparent polymer sheet 756 is wound around drum 752. Vacuum web coater 754 is a device which converts a polymer sheet to a metalized reflective material, by depositing a reflective material, such as gold, aluminum, chromium, mercury, and the like, on a moving polymer sheet. Vacuum web coater 754 operates according to a vacuum web coating process as known in the art. Transparent polymer sheet 756 is made of a small gage (i.e., thin) and flexible polymer.

As drum 752 rotates, transparent polymer sheet 756 is fed into vacuum web coater 754, from a first side 758 of vacuum web coater 754. A transparent sheet 760 is located at a second side 762 of vacuum web coater 754, opposite to first side 758. Transparent sheet 760 is made of a transparent material, such as glass, polymer, and the like. As transparent polymer sheet 756 moves through vacuum web coater 754, vacuum web coater 754 coats transparent polymer sheet 756 with the reflective material. Transparent polymer sheet 756 which is now coated with the reflective material, is attached to transparent sheet 760, for example, by employing an adhesive, welding, and the like. Transparent sheet 760 which now includes transparent polymer sheet 756 after being coated with the reflective material, is formed into the desired concave shape of refrigerator cover 102, as described herein above in connection with FIGS. 1 and 2, by a method known in the art.

Reference is now made to FIG. 18, which is a schematic illustration of a system generally referenced 790, for reducing the thermal load on a top-open reach-in refrigerator, constructed and operative according to a further embodiment of the disclosed technique. System 790 includes a refrigerator cover 792, a pair of reach-in refrigerators 794 and 796, and a plurality of dehumidifiers 798 and 800. Refrigerators 794 and 796 include openings 802 and 804, respectively. Dehumidifier 798 includes an outlet air tubing 806 and a return air tubing 808. Dehumidifier 800 includes an outlet air tubing 810 and a return air tubing 812.

Refrigerator cover 792, reach-in refrigerators 794 and 796, and dehumidifiers 798 and 800, are located in a confinement 814. Refrigerator cover 792, and each of refrigerators 794 and 796 are similar to refrigerator cover 102 and refrigerator 118, respectively, as described herein above in connection with FIGS. 1 and 2. Each of dehumidifiers 798 and 800 is a device which sucks in the air in confinement 814, and blows out an air whose humidity is lower than that of the air in confinement 814. Refrigerator cover 792 is located above refrigerators 794 and 796.

An outlet 816 of dehumidifier 798 is coupled with a first side-panel 818 of refrigerator 794, by outlet air tubing 806. An inlet 820 of dehumidifier 798 is coupled with a second side-panel 822, by return air tubing 808. An outlet 824 of dehumidifier 800 is coupled with a third side-panel 826 of refrigerator 796, by outlet air tubing 810. An inlet 828 of dehumidifier 800 is coupled with a fourth side-panel 830 of refrigerator 796, by return air tubing 812.

Dehumidifier 798 blows out dehumidified (i.e., dry) air into opening 802, through outlet 816. This dehumidified air evaporates, thereby consuming heat from the surrounding, which in turn cools an interior volume 832 of refrigerator 794. In this manner, the thermal load on a heat pump (not shown) of refrigerator 794 is reduced. Dehumidifier 798 sucks in the humidified air through second side-panel 822, return air tubing 808, and inlet 820. The flow of air from first side-panel 818 to second side-panel 822 forms an air curtain above interior volume 832.

Dehumidifier 800 operates in a similar manner. Alternatively, each of the dehumidifiers can be integrated with the respective refrigerator.

Reference is now made to FIGS. 19A, 19B, and 19C. FIG. 19A is a thermal analysis of a pair of refrigerators with no refrigerator cover above the refrigerators. FIG. 19B is a thermal analysis of a pair of refrigerators with a refrigerator cover located at a distance above, having a geometry of a portion of a cylinder, wherein the inner surfaces of the side panels of the refrigerators of FIG. 4A, are coated with a substantially low emissivity thermo-reflective material (in this example it is 3%). FIG. 19C is a thermal analysis of a pair of refrigerators with a refrigerator cover located at a distance above, having a geometry of an ellipsoid, wherein the inner surfaces of the side panels of the refrigerators of FIG. 4A, are coated with a substantially low emissivity thermo-reflective material. The results of this thermal analysis are listed herein below in Table 1.

The thermal analysis detailed in Table 1, referring to each of FIGS. 19A, 19B, and 19C were performed at the following conditions:

• • Ambient temperature: 25 degrees Celsius
  • Temperature of the articles in the refrigerators: −18 degrees Celsius
  • E_OUT denotes the black body irradiation energy of each the refrigerators
  • E_ELECTRIC denotes the electric power in watts required for evacuating the heat entering by radiation, based on Carno heat machine with efficiency of 58%
  • Dimensions of the confinement (e.g., room) in which the refrigerators are located: height 3.5 m, length 12 m, width 4.5 m.
  • Length of the reach-in refrigerators: 10.95 m
  • Radius of the base of the cylinder of FIG. 19B: 2.195 m
  • The length of cord of the portion of the cylinder of the refrigerator cover of FIG. 19B: 3.8 m
  • The distance between the top of the refrigerators to the top of the refrigerator cover of FIG. 19B: 2.195 m
  • Sum of the distances from any point on surface of the ellipsoid of the refrigerator cover of FIG. 19C, to the focal points: 2.4926 m
  • The conic constant K of the ellipsoid of the refrigerator cover illustrated in FIG. 19C, is equal to 0.221216
  • The length of the cord of the ellipsoid of the refrigerator cover of FIG. 19C: 3.8 m
  • The distance between the top surface of the refrigerator to the top of the refrigerator cover of FIG. 19C: 2.041 m
  • E_SAVED denotes the energy saved in each of the cases, compared with the case of FIG. 19A.
  • Q_H/A denotes to the total heat energy by radiation (i.e., excluding conduction and convection) which originates from the surrounding environment of the refrigerator, in each case, in units of W/m²
  • Q_C/A denotes the energy balance of radiation (i.e., excluding conduction and convection) into the refrigerator, which has to be evacuated by heat pump, per unit of area, in units of W/m², in order to keep the temperature of the articles at −18 degrees Celsius.

TABLE 1
						ELLIPSOID
Case	QH/A	EOUT	QC/A	EELECTRIC	ESAVED	ADVANTAGE
FIG. 19A	450	239	211	364	0
FIG. 19B	287	239	81	140	−224
FIG. 19C	320	239	48	83	−281	57

It will be appreciated by persons skilled in the art that the disclosed technique is not limited to what has been particularly shown and described hereinabove. Rather the scope of the disclosed technique is defined only by the claims, which follow.

Claims

1. Energy optimized reach-in refrigerator overhead illumination system, for decreasing heat transfer from the environment to a reach-in refrigerator, the reach-in refrigerator having an opening facing upward, the illumination system comprising: at least one refrigerator illuminator for illuminating at least one respective region of said opening;an curved opaque thermo-reflective extension surrounding said at least one refrigerator illuminator, said opaque thermo-reflective extension being located at a distance above said opening, the inner portion of said opaque thermo-reflective extension, which points toward said opening, being made of a substantially low emissivity thermo-reflective material, said inner portion reflecting infrared radiation which arrives external to said reach-in refrigerator, to a region external to said reach-in refrigerator; andan opaque thermo-reflective extension fixation mechanism for fixing said at least one refrigerator illuminator, and said opaque thermo-reflective extension above said opening.

2. The illumination system according to claim 1, further comprising at least one infrared radiation filter located between a respective one of said at least one refrigerator illuminator and said opening, said at least one infrared radiation filter transmitting visible light emitted by a respective one of said at least one refrigerator illuminator, and substantially blocking infrared radiation emitted by said respective refrigerator illuminator.

3. The illumination system according to claim 1, further comprising at least one heat conveyor coupled with said respective refrigerator illuminator, said at least one heat conveyor transferring the heat dissipated by said respective refrigerator illuminator, to said environment.

4. The illumination system according to claim 3, wherein said at least one heat conveyor is an active heat transfer device.

5. The illumination system according to claim 3, wherein said at least one heat conveyor is a passive heat transfer device.

6. The illumination system according to claim 1, wherein said thermal radiation is a far infrared radiation.

7. The illumination system according to claim 1, wherein said opaque thermo-reflective extension is made of a substantially low density material.

8. The illumination system according to claim 1, wherein said opaque thermo-reflective extension is made of a substantially low density material selected from the list consisting of: foamed polymer;polystyrene;polyolefin;polycarbonate;polyethylene;polypropylene; andair containing structure.

9. The illumination system according to claim 1, wherein said opaque thermo-reflective extension is made of an opaque material.

10. The illumination system according to claim 1, wherein said substantially low emissivity thermo-reflective material is selected from the list consisting of: metallic foil;metalized foil; andelectrolytic coating;

11. The illumination system according to claim 1, wherein said fixation mechanism is coupled with a ceiling in which said illumination system is located.

12. The illumination system according to claim 1, wherein said fixation mechanism is coupled with said reach-in refrigerator.

13. The illumination system according to claim 1, further comprising an optical assembly located between said infrared radiation filter and said opening, said optical assembly imparting at least one optical property to said visible light, to transmit said visible light from said infrared radiation filter toward said opening.

14. The illumination system according to claim 1, wherein an inner surface and a top surface of at least one side panel of said reach-in refrigerator is coated with a side-panel thermo-reflective material, and wherein said side-panel thermo-reflective material reflects said infrared radiation which arrives external to said reach-in refrigerator, to a region external to said reach-in refrigerator.

15. The illumination system according to claim 14, wherein said side-panel thermo-reflective material is made of a multilayer laminate containing an aluminum foil.

16. The illumination system according to claim 14, wherein said side-panel thermo-reflective material is made of a multilayer laminate containing a metalized foil.

17. The illumination system according to claim 1, wherein an inner surface of at least one side panel of said reach-in refrigerator, is in the form of an infrared radiation filter, wherein a top surface of said at least one side panel is coated with said substantially low emissivity thermo-reflective material,wherein said infrared radiation filter substantially transmits said visible light toward an inner region of said reach-in refrigerator, andwherein said infrared radiation filter further substantially blocks said infrared radiation.

18. The illumination system according to claim 1, further comprising an opaque side-panel coupled with said opaque thermo-reflective extension, wherein said opaque side-panel covers a concave surface of said opaque thermo-reflective extension, at an extreme side of said opaque thermo-reflective extension, along a substantially flat surface substantially perpendicular to a longitudinal axis of said opaque thermo-reflective extension, andwherein said opaque side-panel substantially blocks said visible light and said infrared radiation, which arrive external to said reach-in refrigerator.

19. The illumination system according to claim 1, further comprising an opaque side-panel coupled with said opaque thermo-reflective extension, wherein said opaque side-panel substantially entirely covers a region at a side of said reach-in refrigerator, from said inner portion, to a top edge of said reach-in refrigerator, along a substantially flat surface, in a direction substantially perpendicular to a floor on which said reach-in refrigerator is located, andwherein said opaque side-panel substantially blocks said visible light and said infrared radiation, which arrive external to said reach-in refrigerator.

20. The illumination system according to claim 1, further comprising a side panel coupled with said opaque thermo-reflective extension, wherein a first portion of said side panel covers a concave surface of said opaque thermo-reflective extension, at an extreme side of said opaque thermo-reflective extension, along a substantially flat surface substantially perpendicular to a longitudinal axis of said opaque thermo-reflective extension,wherein a second portion of said side panel extends from a bottom edge of said first portion, along said flat surface, toward a top edge of said reach-in refrigerator,wherein said first portion is made of an opaque and substantially low emissivity thermo-reflective material, to substantially block said visible light and said infrared radiation, andwherein said second portion is made of a substantially transparent material which transmits said visible light, and which substantially blocks said infrared radiation.

21. The illumination system according to claim 1, wherein said opaque thermo-reflective extension includes a plurality of opaque thermo-reflective extension modules, and wherein said opaque thermo-reflective extension, is constructed by coupling together said opaque thermo-reflective extension modules.

22. The illumination system according to claim 21, wherein each of said opaque thermo-reflective extension modules, is made by a process selected from the list consisting of: injection molding;casting;cold molding;compression molding;insert molding;liquid injection molding;multi-shot molding;reaction injection molding;structural foam molding;transfer molding;vacuum forming; andstereolithography.

23. The illumination system according to claim 21, wherein each of said opaque thermo-reflective extension modules, is coated with said substantially low emissivity thermo-reflective material after manufacture of each of said opaque thermo-reflective extension modules.

24. The illumination system according to claim 21, wherein said substantially low emissivity thermo-reflective material is integrated with each of said opaque thermo-reflective extension modules, during the manufacture of each of said opaque thermo-reflective extension modules.

25. The illumination system according to claim 1, further comprising an illuminator reflector located above said opaque thermo-reflective extension, along a median longitudinal axis of said opaque thermo-reflective extension, wherein said refrigerator illuminator is located along said median longitudinal axis,wherein said illuminator reflector reflects said visible light emitted by said refrigerator illuminator, toward said opening,wherein a first portion of said substantially low emissivity thermo-reflective material is located at a first side of said refrigerator illuminator, andwherein a second portion of said substantially low emissivity thermo-reflective material is located at a second side of said refrigerator illuminator.

26. The illumination system according to claim 1, wherein said curved opaque thermo-reflective extension is in the form of an ellipsoid.

27. The illumination system according to claim 26, wherein an ellipsoid center of said ellipsoid is substantially located at the center of a top surface of said opening, and wherein two focal points of said ellipsoid are located at said top surface.

28. The illumination system according to claim 1, wherein said inner portion is coated with said substantially low emissivity thermo-reflective material.

29. The illumination system according to claim 1, further comprising a dehumidifier, said dehumidifier blowing substantially dehumidified air through an outlet at a first side-panel of said reach-in refrigerator, toward an inlet at a second side-panel of said refrigerator, said dehumidifier sucking substantially humidified air through said inlet, to form a substantially dehumidified air curtain above said opening.

30. The system according to claim 1 further comprising a dehumidifier blowing substantially dehumidified air through an outlet at a first side-panel of said reach-in refrigerator, into said opening, to form a substantially dehumidified air curtain above said opening.

31. The system according to claim 30, wherein said dehumidifier blows said dehumidified air toward an inlet at a second side-panel of said refrigerator, and wherein said dehumidifier further sucks substantially humidified air through said inlet.

32. Energy optimized reach-in refrigerator overhead thermal barrier, for decreasing heat transfer from the environment to a reach-in refrigerator, the reach-in refrigerator having an opening facing upward, the thermal barrier comprising: a substantially transparent refrigerator cover located at a distance above said opening, said substantially transparent refrigerator cover being in the form of an ellipsoid, the inner portion of said substantially transparent refrigerator cover, which points toward said opening, being coated by a substantially low emissivity thermo-reflective material, said inner portion reflecting infrared radiation which arrives external to said reach-in refrigerator, to a region external to said reach-in refrigerator, said substantially transparent refrigerator cover transmitting visible light emitted by an overhead light source, located above said substantially transparent refrigerator cover, toward said opening; anda refrigerator cover fixation mechanism for fixing said substantially transparent refrigerator cover above said opening.

33. The thermal barrier according to claim 32, wherein said substantially transparent refrigerator cover is made of a substantially low density material.

34. The thermal barrier according to claim 32, wherein said substantially low emissivity thermo-reflective material is selected from the list consisting of: metallic foil;metalized foil;electrolytic coating;glass mirror; andtransparent polymer coated with a reflective material.

35. The thermal barrier according to claim 32, wherein said fixation mechanism is coupled with a ceiling in which said thermal barrier is located.

36. The thermal barrier according to claim 32, wherein said fixation mechanism is coupled with said reach-in refrigerator.

37. The thermal barrier according to claim 32, wherein said substantially transparent refrigerator cover includes a plurality of refrigerator cover modules, and wherein said substantially transparent refrigerator cover, is constructed by coupling together said refrigerator cover modules.

38. The thermal barrier according to claim 32, wherein the focal points of said ellipsoid are substantially located on a top surface of said opening.

39. The thermal barrier according to claim 32, wherein an ellipsoid center of said ellipsoid is substantially located at the center of a top surface of said opening, and wherein two focal points of said ellipsoid are located at said top surface.

40. The thermal barrier according to claim 32, wherein said inner portion is coated with said substantially low emissivity thermo-reflective material, by employing a vacuum web coater.

41. Energy optimized reach-in refrigerator overhead illumination system, for decreasing heat transfer from the environment to a pair of reach-in refrigerators, located adjacent to one another, each of the reach-in refrigerators having a respective opening facing upward, the illumination system comprising: a pair of refrigerator illuminators, each respective one of said pair of refrigerator illuminators illuminating said respective opening, and a mid-region between said pair of reach-in refrigerators, in the vicinity of a floor on which said pair of reach-in refrigerators are located;a pair of opaque thermo-reflective extensions, each respective one of said pair of opaque thermo-reflective extensions surrounding said respective infrared radiation filter, said respective opaque thermo-reflective extension being located at a distance above said respective opening, each of said opaque thermo-reflective extensions being in the form of an ellipsoid, a respective inner portion of said respective opaque thermo-reflective extension, which points toward said respective opening, being made of a substantially low emissivity thermo-reflective material, said respective inner portion reflecting infrared radiation which arrives external to said respective reach-in refrigerator, and from said mid-region, to a region external to said pair of reach-in refrigerators; andan opaque thermo-reflective extension fixation mechanism for fixing said pair of refrigerator illuminators, said pair of infrared radiation filters, and said pair of opaque thermo-reflective extensions, above said respective opening.

42. The illumination system according to claim 41, further comprising a pair of infrared radiation filters, each respective one of said pair of infrared radiation filters being located between said respective refrigerator illuminator, and said respective opening, said respective infrared radiation filter transmitting visible light emitted by said respective refrigerator illuminator, and substantially blocking infrared radiation emitted by said respective refrigerator illuminator.

43. The illumination system according to claim 41, further comprising an infrared outward reflector located between said reach-in refrigerators, said infrared outward reflector reflecting infrared radiation which arrives external to said reach-in refrigerators, to a region external to said reach-in refrigerators.

44. Energy optimized reach-in refrigerator overhead illumination system, for decreasing heat transfer from the environment to a pair of reach-in refrigerators, located adjacent to one another, each of the reach-in refrigerators having a respective opening facing upward, the illumination system comprising: a refrigerator illuminator illuminating said openings, and a mid-region between said pair of reach-in refrigerators;a infrared radiation filter being located between said refrigerator illuminator and said openings, said infrared radiation filter transmitting visible light emitted by said refrigerator illuminator, and substantially blocking infrared radiation emitted by said refrigerator illuminator;an opaque thermo-reflective extension surrounding said infrared radiation filter, said opaque thermo-reflective extension being located at a distance above said openings, said opaque thermo-reflective extension being in the form of an ellipsoid, an inner portion of said opaque thermo-reflective extension, which points toward said openings, being made of a substantially low emissivity thermo-reflective material, said inner portion reflecting infrared radiation which arrives external to said pair of reach-in refrigerators, and from said mid-region, to a region external to said pair of reach-in refrigerators; andan opaque thermo-reflective extension fixation mechanism for fixing said refrigerator illuminator, said infrared radiation filter, and said opaque thermo-reflective extension, above said openings.

45. The illumination system according to claim 44, further comprising an infrared radiation filter being located between said refrigerator illuminator and said openings, said infrared radiation filter transmitting visible light emitted by said refrigerator illuminator, and substantially blocking infrared radiation emitted by said refrigerator illuminator.

46. Device for decreasing heat transfer from the environment to a pair of reach-in refrigerators, located adjacent to one another, each of the reach-in refrigerators having a respective opening facing upward, the device comprising: an infrared outward reflector located between said pair of reach-in refrigerators, said infrared outward reflector reflecting infrared radiation which arrives external to said reach-in refrigerators, to a region external to said reach-in refrigerators.

47. The device according to claim 46, wherein said infrared outward reflector comprises a plurality of elongated retroreflectors.

48. The device according to claim 46, wherein said infrared outward reflector comprises a plurality of corner retroreflectors.

49. The device according to claim 46, wherein said infrared outward reflector comprises at least one concave surface.

50. The device according to claim 46, wherein said infrared outward reflector further comprises an image located behind an infrared reflective surface of said infrared outward reflector, and wherein said infrared reflective surface is made of a substantially transparent material.

51. The device according to claim 46, wherein said infrared radiation infrared radiation source is located within said environment.

52. The device according to claim 46, wherein said infrared radiation source is at least one refrigerator cover located at a distance above said respective opening.

53. The device according to claim 52, wherein said at least one refrigerator cover is in the form of an ellipsoid.

54. The device according to claim 52, wherein said at least one refrigerator cover is made of an opaque material, having a concave geometry, wherein a respective inner portion of said at least one refrigerator cover, which points toward said respective opening, is made of a substantially low emissivity thermo-reflective material,wherein said respective inner portion emits infrared radiation toward said respective opening, andwherein said infrared outward reflector returns said infrared radiation originating from said respective inner surface, back toward said respective inner surface.

55. The device according to claim 52, wherein said at least one refrigerator cover is made of a substantially transparent material, having a concave geometry, wherein a respective inner portion of said at least one refrigerator cover, which points toward said respective opening, is coated by a substantially low emissivity thermo-reflective material,wherein said respective inner portion emits infrared radiation toward said respective opening, andwherein said infrared outward reflector returns said infrared radiation originating from said respective inner surface, back toward said respective inner surface.

56. Device for decreasing heat transfer from the environment to a reach-in refrigerator, the reach-in refrigerator having an opening facing upward, the device comprising: a dehumidifier blowing substantially dehumidified air through an outlet at a first side-panel of said reach-in refrigerator, into said opening, to form a substantially dehumidified air curtain above said opening.

57. The device according to claim 56, wherein said dehumidifier blows said dehumidified air toward an inlet at a second side-panel of said refrigerator, and wherein said dehumidifier further sucks substantially humidified air through said inlet.