Closed refrigerated cabinet

Abstract

A closed refrigerated cabinet (1) comprising at least one closing door (2) including at least one insulating glass unit (20), and an air curtain system (3) adapted to produce an air curtain (30) inside the cabinet and in the immediate vicinity of the insulating glass unit (20), the insulating glass unit (20) comprising at least two glass substrates (21, 22) separated by at least one gas gap, having a front face facing the external environment of the cabinet and a rear face in contact with the interior of the cabinet, and the glass unit comprising a first low-emissivity coating arranged on one face of the glass unit in contact with the gas gap, characterized in that the insulating glass unit (20) comprises a second low-emissivity coating (4) arranged on the rear face of the glass unit, and the cabinet further comprising profiled elements (5) interacting with the air curtain. Figure 1

Description

Title of the invention: Closed refrigerated cabinet

[0001] The invention relates to a refrigerated cabinet or refrigerated enclosure, closed by a transparent glazed opening comprising at least one insulating glazing.

[0002] The invention will be described more particularly with regard to a refrigerated piece of furniture for commercial premises, without however being limited to it.

[0003] A refrigerated display case is used to showcase products for sale at a specific storage temperature. For open (doorless) units, an air curtain is generated on the front to maintain the temperature difference between the refrigerated volume of the unit and the ambient temperature of the store, thus keeping the cold air inside. Such an air curtain, which maintains the cold air within the unit, is often also used for units with doors, the openings of which are frequently opened to access the products. Furthermore, to contribute to the thermal insulation of the unit, a low-emissivity coating typically covers one side of one of the glass substrates of the insulating glazing of the opening panel. This low-emissivity coating blocks infrared radiation emitted from the ambient air of the store.Furthermore, the insulating glazing of a refrigerated display case door may have one of the glass substrates that is heated to prevent condensation or fogging.

[0004] These different solutions, especially when combined, consume energy which it is always desirable to save.

[0005] The invention aims to provide a closed refrigerated cabinet with at least one opening, designed to reduce energy consumption while maintaining the appropriate temperature inside the cabinet. The invention applies to both positive and negative temperature refrigerated cabinets.

[0006] According to the invention, the closed refrigerated cabinet comprises at least one closing opening including at least one insulating glass panel (which extends along a general plane), and an air curtain system adapted to produce an air curtain inside the cabinet and in the immediate vicinity of the insulating glass panel (in a direction (vertical for a vertical cabinet) parallel or substantially parallel to the plane of extension of the insulating glass panel), the insulating glass panel comprising at least two glass substrates separated by at least one gas layer, having a so-called front face facing the external environment of the cabinet and a so-called rear face in contact with the inside of the cabinet and the glass panel comprising a first low-emissivity coating which is arranged on a face of the glass panel in contact with the gas layer (inside the cavity of the insulating glass panel),the furniture being characterized in that the insulating glazing comprises a second low-emissivity coating which is arranged on the back face of the glazing, on the , The substrate is in contact with the interior of the furniture, and the furniture also includes profiled elements that interact with the air curtain (the profiled elements being separate from the shelf label holders included in the furniture). The second low-emissivity coating is in direct contact with the interior environment of the furniture.

[0007] Thus, while it is common for insulating glass in refrigerated cabinets to include a low-emissivity (internal) coating on the inside of the insulating glass (said first low-emissivity coating), the glazing of the invention further comprises, in combination, an additional low-emissivity coating arranged on the face of the glass substrate, which corresponds to the face in direct contact with the interior environment of the cabinet (face 4 for double glazing or face 6 for triple glazing), and profiled elements interacting with the air curtain. It should be noted that, according to a common definition, face 1 of glazing mounted in a closed structure is the face in direct contact with the environment outside the structure.

[0008] The profiled elements allow the air to be guided along the glazing and reduce the airflow (the speed) along the glazing when the opening is closed.

[0009] According to one characteristic, the profiled elements are in the immediate vicinity of the glazing, that is to say are at a distance from the glazing of at most 50 mm, are in particular at a distance between 2 and 50 mm and preferably are at a distance between 5 and 20 mm.

[0010] The inventors have demonstrated that, surprisingly, the energy savings provided by the combination of profiled elements and a low-emissivity coating coupled with insulating glazing on the interior face of the cabinet (rear face of the insulating glazing) are particularly significant for a closed cabinet, far exceeding the combined savings achieved by considering a cabinet comprising either the profiled elements or the low-emissivity coating inside the cabinet. Indeed, the profiled elements contribute to reducing the air velocity along the glazing, thereby lowering the convective heat transfer coefficient hconv, and the second low-emissivity coating, which is external to the insulating glazing but internal to the cabinet, contributes to reducing the radiative heat transfer coefficient hradiatif, ultimately decreasing the thermal transmittance coefficient Ug to a much greater extent than expected.The combination of profiled elements and the low-emissivity coating in contact with the interior of the cabinet provides an unexpected synergy, very effectively lowering the Ug value of the opening and consequently maximizing energy savings. When the opening is closed, which is the case for a large part of the cabinet's operating time (for example, over a 24-hour period), energy savings are guaranteed. In particular, this even allows for a significant reduction in the heating of the insulating glazing when heating elements are present, and it also leads to a reduction in the refrigeration unit's energy consumption. Moreover, the invention allows action to be taken independently of the ventilation control; for existing furniture, it is therefore sufficient to change the opening of the furniture to achieve a reduction in energy consumption.

[0011] The invention also relates to the use in a refrigerated cabinet closed by a closing door, of insulating glazing forming the closing door and comprising in combination a low emissivity coating arranged on the face of the insulating glazing, which is in contact with the interior of the cabinet, and profiled elements arranged in the immediate vicinity of the insulating glazing, preferably substantially inclined with respect to it, in order to reduce the total heat transfer coefficient H (hconv + hradiative) such that it is less than 5 W / m2. K, and even less than 4 W / m2. K.

[0012] In the following description, the terms "horizontal", "vertical", "upper", "lower", "top", "bottom" are used in the context of a normal installation of the furniture, that is to say relating to a vertical notion in relation to a flat horizontal floor on which the furniture would be placed.

[0013] According to one feature, the emissivity of the rear face of the insulating glazing and interior to the furniture, having the second low emissivity coating, is less than 0.3, in particular less than 0.05, preferably less than 0.03.

[0014] In particular, the insulating glazing comprises two or three glass substrates, in particular each 4 mm thick, and a gas layer between two substrates, in particular argon, with a thickness of between 10 and 16 mm, in particular between 10 and 12 mm for a freezer as a refrigerated unit and between 14 and 16 mm for a refrigerator as a refrigerated unit. According to one feature, the face of the glazing having the first low-emissivity coating (the first low-emissivity coating being arranged on one of the faces of the substrates in contact with the gas layer) has an emissivity of at most 0.05, or even at most 0.03, and even better at most 0.01.

[0015] According to one feature, the second low-emissivity coating is a stack of thin films, in particular comprising at least one metallic layer based on silver or metallic alloy, or at least one layer (which is not metallic) of a transparent conductive oxide (TCO), in particular of the ITO (tin-doped indium oxide) or SnO2:F type.

[0016] According to one characteristic, the second low-emissivity coating has a thickness between 50 and 150 nm.

[0017] According to one feature, each of the profiled elements is inclined with respect to a plane parallel to the so-called extension plane of the insulating glazing (with respect to the vertical in a tall cabinet) and with respect to the direction of air intake, which is parallel to the extension plane of the glazing (the air curtain is parallel to the extension plane of the glazing). In particular, the profiled elements are inclined towards the inside of the cabinet. relative to the direction of air intake, in order to create deflectors to divert the direction of the air towards the inside of the furniture. According to one characteristic, each of the profiled elements has two opposing end edges (whose connecting surface corresponds to the plane of inclination of the profiled element and the edges are therefore in offset vertical planes), one of the edges being closer to the glazing while the other edge is further from the glazing, the inclination of each of the profiled elements is such that the end edge closest to the glazing is located on the side of the air intake.In particular, when the refrigerated unit is vertical with vertically extending insulated glazing and the air intake is from bottom to top, each of the profiled elements is inclined, converging towards the interior of the unit (and towards the top of the glazing), and has a so-called lower edge and an opposite edge called the upper edge. The edge closest to the glazing is the lower edge, while the upper edge is furthest from the glazing.

[0018] Advantageously, each of the profiled elements is inclined relative to the so-called extension plane of the insulating glazing at an angle q between 20 and 30°, preferably of the order of 25°.

[0019] According to one feature, each of the profiled elements has a cross-section comprising two opposing principal faces that are parallel or substantially parallel, one of the faces interacting directly with the air curtain, and both faces being inclined relative to the plane of the insulating glazing. In particular, the cross-section of the profiled element is the portion separating the two opposite end edges of the profiled element.

[0020] According to one characteristic, each of the profiled elements (being inclined with respect to the so-called extension plane of the insulating glazing) is at a distance from the insulating glazing between 2 and 50 mm, preferably between 2 and 20 mm, in particular each of the profiled elements being inclined so as to present a point furthest from the glazing (its furthest end edge) which is at most 50 mm.

[0021] In a preferred example, each of the profiled elements has a width (direction perpendicular to the length of the profiled element and distance separating the two end edges) of 50 mm and is inclined at 20° to the plane of the insulating glazing, having a first end closest to the glazing (its nearest end edge) which is 5 mm away and a second opposite end (its furthest end edge and in the direction of the interior of the furniture) which is 20 mm away from the glazing.

[0022] According to one characteristic, each of the profiled elements extends longitudinally in the direction perpendicular to the direction of air supply (i.e., along the horizontal for a vertical piece of furniture and therefore along the width of the glazing, direction perpendicular to the height).

[0023] According to one feature, each of the profiled elements has a cross-section (the cross-section corresponds to the transverse dimensions to the length of the profile) that is flat or substantially flat. The cross-section is defined by two opposing principal faces and two opposing end edges connecting the two faces. A "flat cross-section" is understood to be a cross-section that has the same width from one edge to the opposite edge, and a "substantially flat cross-section" is understood to be a cross-section that has the same width from one end edge to the opposite end edge, without having a prominent convex shape. According to one feature, the distance separating the two opposite faces (thickness of the profiled element) is at most 5 mm, in particular 1 mm.

[0024] Consequently, each of the profiled elements has, in particular, two opposing principal faces and two opposing end edges connecting the principal faces, the principal faces being flat or substantially flat. In particular, the profiled elements do not need to have an aerodynamic profile (with a pronounced camber on one of the faces). This notably simplifies the manufacture of the profiled elements. The inventors have demonstrated, contrary to expectations, that a flat (and non-aerodynamic) shape is suitable in combination with the inclination of the profiled elements.

[0025] Preferably, each of the profiled elements has an oblong cross-section, in particular rectangular, diamond, or elliptical (if the profiled element has the shape of an ellipse, its small axis is at most 5mm).

[0026] In particular, each of the profiled elements has an oblong cross-section whose length (distance separating the two opposite edges) is at most 50 mm.

[0027] According to one feature, each of the profiled elements includes fastening parts that project from a so-called longitudinal face of the profiled element. In particular, each of the profiled elements extends longitudinally while the fastening parts are located at the terminations of the profiled element or located at various points along the profiled element.

[0028] According to one feature, the opening includes a frame around the insulating glazing and the furniture includes shelves, the profiled elements being fixed to the glazing (to the so-called internal glass substrate of the insulating glazing) and / or to the frame and / or to the shelves.

[0029] According to one characteristic, each of the profiled elements is made of transparent glass and / or transparent plastic material such as polymethyl methacrylate.

[0030] According to one characteristic, the furniture is positive or negative cold and forms a vertical piece of furniture.

[0031] The present invention is now described by means of purely illustrative and in no way limiting examples of the scope of the invention, and from the accompanying illustrations, in which: - [Fig.l] represents a schematic cross-sectional and side view of an example embodiment according to the invention of a closed refrigerated vertical cabinet, with an airflow circulating from bottom to top. - [Fig.2] corresponds to another example of the realization of a closed refrigerated vertical cabinet with an airflow circulating from top to bottom. - [Fig.3] is a detailed schematic cross-sectional view of the glazing and a profiled element fixed to the glazing according to the realization of [Fig.1]. - [Fig.4] is a partial perspective view of an example of the realization of a profiled element of the furniture of the invention. - [[Fig.5]] is a partial schematic top view of the furniture according to an example of the realization of fixing a profiled element. - [[Fig.6]] corresponds to [Fig.5] according to another example of fixing a profiled element. - [[Fig.7]] is an enlarged schematic top view of one edge of the furniture showing yet another example of fixing a profiled element. - [[Fig.8]] is a schematic view showing another example of fixing a profiled element, the latter being fixed to a shelf of the furniture with air circulating from top to bottom.

[0032] The figures are schematic and not to scale to facilitate reading.

[0033] The refrigerated and closed cabinet 1 of the invention, illustrated in Figures 1 and 2, is as follows: for example, a vertical display unit for a shop.

[0034] The refrigerated cabinet 1 comprises a cabinet body 10 whose internal volume is refrigerated at positive or negative temperatures, and a closing door 2 which includes insulating glazing 20 whose internal substrate 21 facing the interior of the cabinet is made of glass. The refrigerated cabinet 1 includes an air curtain system 3 adapted to produce an air curtain 30 inside the cabinet and in the immediate vicinity and parallel to the door 2.

[0035] According to the invention, the refrigerated cabinet 1 comprises, in combination, on the one hand, a low emissive coating 4 coupled to the insulating glazing and in contact with the interior of the cabinet, preferably disposed over the entire face of the internal glass substrate 21, inside the cabinet, and on the other hand, profiled elements 5 for guiding and stabilizing the air curtain 3, which are arranged in the immediate vicinity of the opening 2.

[0036] The air curtain system 3, which is known per se, comprises at least one fan (not shown) and one heat exchanger (not shown), as well as an air supply vent 11 and an air return vent 12 inside the cabinet for the air circulation. In the vertical unit 1, the air supply vent 11 can be at the upper end and the air recovery vent 12 is located at the lower end, as illustrated in [Fig.1], providing an airflow in the direction of bottom to top, or the air supply vent 11 and the air recovery vent 12 are located respectively at the lower end and upper end, as illustrated in [Fig.2], providing an airflow in the direction of top to bottom.

[0037] The opening 2 comprises an insulating and transparent glazing unit 20 and a frame 2' that surrounds and supports the glazing unit 20. The frame 2' is movably fixed, preferably by pivoting, to the body 10 of the unit. The insulating glazing unit 20 comprises at least two glass substrates, internal 21 and external 22, and a gas layer 23. The glass substrates are held parallel and spaced apart by a spacer (not shown here), preferably transparent, arranged around the entire periphery of the substrates. The glazing unit 20 may be double-glazed (two glass substrates) or triple-glazed (three glass substrates). The insulating glazing unit 20 has a front face in contact with the external environment and a rear face in contact with the interior of the unit when the opening is closed. The front face is face 1 and the rear face is face 4 for double glazing 20 or face 6 for triple glazing.

[0038] The glass substrates 21 and 22 are, for example, rectangular in shape. Alternatively, they may have other geometries such as square, round, oval, etc. The glass substrates 21 and 22 are preferably flat; alternatively, they may be curved. The glass substrates 21 and 22 are preferably made of tempered glass. The thickness of each of the glass substrates is between 2 and 5 mm, and is preferably 3 or 4 mm in order to minimize the overall weight of the glazing and optimize light transmission.

[0039] The gas gap 23 has a thickness of at least 4 mm and is adapted according to the desired performance of the Ug thermal transmittance coefficient, but not exceeding 16 mm, or even 20 mm. The gas gap 23 consists of air or, preferably, to enhance the insulation level of the glazing, of a noble gas, chosen from argon, krypton, xenon, or a mixture of these different gases, with a filling rate of at least 85%. For an even better Ug coefficient, a filling with at least 92% krypton or xenon is preferred.

[0040] The spacer providing the spacing between the glass substrates is preferably of low thermal conductivity, having a linear thermal transmittance coefficient of at most 1 W / mK, preferably less than 0.7 W / mK, and even less than 0.4 W / mK.

[0041] The insulating glazing includes a first low-emissivity coating 23' which is on one of the faces of the glazing inside the cavity of the insulating glazing (face 2 or 3 for double glazing), in contact with the gas layer.

[0042] The insulating glazing further comprises a second low-emissivity coating 4 which is arranged on the outer face of the internal substrate 21 of the insulating glazing 20 of the opening (face 4 for double glazing or face 6 for triple glazing), the face which is the one in direct contact with the interior of the furniture. The low-emissivity coating 4 is a stack of thin films, in particular comprising one or more silver layers surrounded by dielectric layers, or layers based on doped metal oxide such as SnO2:F or tin-doped indium oxide (ITO). The low-emissivity coating 4 has, for example, a thickness between 60 and 140 nm.

[0043] The insulating glazing 20 with its low emissivity coating 4 has in particular an emissivity of 0.03.

[0044] The air curtain system 3 provides an air curtain 30 along the internal substrate 21 of the sash. The air curtain 30 cooperates with the profiled elements 5. The profiled elements 5 are in the immediate vicinity of the sash 2, in particular at a distance of approximately 2 mm to 50 mm from the sash 2. The profiled elements 5 ([Fig.3] and [Fig.4]) form longitudinal and substantially parallel flat surfaces, which are inclined with respect to the extension plane of the insulating glazing 20. The profiled elements 5 extend lengthwise transversely to the direction of the (vertical) airflow of the air curtain 30 and parallel to the sash 2 (in its closed position), i.e. here along the width of the sash 2 (horizontal direction). The profiled elements 5 have two opposing main faces 50 and 51 and two opposing edges, a lower end 52 and an upper end 53, connecting the two main faces. Each of the profiled elements 5 has a flattened cross-section.The thickness of a profiled element, or the distance separating the two opposite faces 50 and 51, is in particular at most 5 mm, and is, for example, 1 mm. Advantageously, one of the faces of the profiled element does not need to be curved according to an aerodynamic profile. The inventors have shown that a flat profile of the profiled element, or even if it is elliptical but with a minor axis not exceeding 5 mm (which constitutes a substantially flat surface), combined with an angular inclination relative to the vertical of the opening so as to provide a reflector that directs the air curtain 30 towards the interior of the furniture opposite the opening, gives very high-performance results.

[0045] Each profiled element 5 is inclined relative to the plane of the insulating glazing, converging towards the interior of the cabinet to deflect or reflect the air curtain 30 towards the interior of the cabinet. The profiled element is inclined upwards or downwards depending on the direction of arrival of the air curtain. When the air curtain arrives from below, with the air supply vent 11 being in the lower part of the cabinet ([Fig. 1]), The profiled elements 5 are inclined upwards and converge towards the interior of the unit. When the air curtain arrives from above, with the air supply vent 11 located at the top of the unit ([Fig. 2] and [Fig. 8]), the profiled elements are inclined downwards and converge towards the interior of the unit. The inclination is such that the main faces 50 and 51 form an angle θ ([Fig. 3]) with the vertical or the plane of the glazing, between 20 and 30°, preferably around 25°. The leading face 50 of the profiled element ([Fig.3]), the face in direct contact with the arrival of the air curtain flow, is therefore inclined and is such that, when the air flow goes from bottom to top ([Fig.1]), the lower end edge 52 is closest to the glazing while the upper end edge 53 is furthest from the glazing.Conversely, the opposite leading face 51 of the profiled element, the face in direct contact with the incoming air curtain flow, is therefore inclined such that, when the airflow is from top to bottom ([Fig. 2]), the upper end edge 53 is closest to the glazing while the lower end edge 52 is furthest from the glazing. In the example of [Fig. 3], the profiled element has a width, the distance from edge 52 to the opposite edge 53, of 50 mm, and the lower edge 52 is 5 mm from the insulating glazing and the upper edge 53 is 20 mm from the insulating glazing. The air curtain, for example, has a velocity of 1 m / s. In Figures 1 and 2, the profiled elements 5 are close to the glazing 20. In [Fig.[8] The profiled element 5 shown is fixed to a shelf 1' (to the end label holder of the shelf), the profiled element 5 being inclined towards the inside of the furniture; the air coming from the upper part of the furniture implies that the profiled element is inclined converging inwards and towards the lower part of the furniture.

[0046] Depending on the type of attachment to the furniture, the profile elements 5 include suitable attachment means (in terms of type, position, and number). For example, the profile elements 5 include spaced attachment supports 54, either near the ends of a profile element or located in several places. The attachment supports 54 extend transversely to the longitudinal direction of the profile elements 5. The attachment supports 54 are integral with one of the faces, such as the face 51 opposite the face 50, which is intended to reflect the air curtain. The attachment supports 54 are integrated as a single unit into the body of a profile element, for example, by the manufacturing process of the profile elements, such as molding, or are attached, for example, by clipping or gluing.

[0047] The profiled elements 5 can be fixed: - on the furniture ([Fig.5]), for example on the side walls of the body 10 of the furniture, for example by screwing or clipping, and / or on the label holders of the shelves 1' of the furniture ([Fig.8]), for example by clipping, and / or - on the 2' frame of the opening ([Fig.6]), for example by gluing or screwing, and / or - on the glazing 20 ([Fig.7]), for example via a support 54 clipped onto the vertical edges of the glazing and sandwiched between the glazing 20 and the frame 2' of the opening.

[0048] The profiled elements 5 and the fixing supports 54 are preferably made of a transparent material such as glass or transparent plastic.

[0049] The inventors have demonstrated that the combination, on the one hand, of the low-emissivity coating 4 arranged on the insulating glazing and on a face turned towards the inside of the furniture, and on the other hand, of the profiled elements 5, in particular arranged in the immediate vicinity of the insulating glazing and inclined relative to the plane of the glazing and towards the inside of the glazing so as to serve as a deflector for the air curtain, makes it possible to minimize the total heat transfer coefficient H (sum of the convective heat transfer coefficient hconv and the radiative heat transfer coefficient hradiatif) such that it is less than 10 W / m2.K, or even less than 7 W / m2.K, and even less than 4 W / m2.K.

[0050] Calculations of the total heat transfer coefficient H were carried out and grouped in Table 1 below in order to compare furniture: - equipped with the second low-emissivity layer on face 4 or lacking this second low-emissivity layer, providing a face 4 emissivity of 0.03 (with layer) or 0.84 without layer, and - including or not profiled elements 5, the profiled elements extending over the entire width of the insulating glazing, having a width of 50 mm and having a flat diamond section shape of 1 mm thickness according to the greatest thickness of separation of the opposite faces 50 and 51.

[0051] Emissivity is measured according to the protocol described in standard NF EN 12898 (2019).

[0052] The total heat transfer coefficient H is calculated as the sum of the convective heat transfer coefficient hconv and the radiative heat transfer coefficient hradiatif. The convective heat transfer coefficient hconv and the radiative heat transfer coefficient hradiatif are calculated in the usual way using known mathematical formulas for these coefficients and from measurements of the heat flux, chosen here to be measured on face 1, the temperature of the glazing on face 4, the temperature of the glazing on face 1, and the temperatures inside and outside the cabinet. The heat flux is measured by flux sensors at several locations on the glazing on face 1 and by averaging the measurements. The temperature on face 1 is obtained using a thermocouple on face 1.The temperature on side 4 is measured by a thermocouple on side 4, or is estimated from the flux measured on side 1 and the temperature measured on side 1, or from the aforementioned measurements on side 4 on the one hand, and from side 1 on the other, comparing these measurements to validate their consistency. Finally, the internal temperature. The furniture temperature is an average of the temperatures measured at several locations on the furniture surfaces.

[0053] [Tables] Total heat transfer coefficient H in W / m².K for the unit without profiled elements. Total heat transfer coefficient H in W / m².K for the unit with profiled elements. Emissivity of surface 4 of the glazing = 0.84 10.3 6.5 Emissivity of surface 4 of the glazing = 0.03 8.8 3.7

[0054] It is observed that the use of a low-emissivity coating does indeed reduce the total heat transfer coefficient H by 1.5 W / m².K, or 15% (the coefficient decreases from 10.3 to 8.8) of a piece of furniture. However, by combining low-emissivity glazing with the aforementioned profiled elements of the invention, the reduction in the total heat transfer coefficient H between a piece of furniture with only low-emissivity glazing and the piece of furniture of the invention is 5.1 W / m².K, representing a very significant reduction of more than 50%.

[0055] Furthermore, it has been shown that the combination according to the invention of insulating glazing with a low-emissivity coating and the presence of profiled elements has an impact on the thermal transmittance coefficient Ug of the insulating glazing. In particular, Table 2 below shows comparative values ​​of the thermal transmittance coefficient Ug for two pieces of furniture with insulating glazing, respectively, without a second low-emissivity coating (glazing emissivity of 0.84) and with the second low-emissivity coating (glazing emissivity of 0.03), and a piece of furniture without profiled elements (hconv of 10 W / m².K) and a piece of furniture with profiled elements (hconv of 3 W / m².K). The calculation of the thermal transmittance coefficient Ug corresponds, as is known, to the ratio between the heat flux density in W / m² (heat flux passing through the surface of the glazing) and the difference in air temperature between the outside and inside of the furniture.The heat flux density is measured in a known manner by a heat flux sensor.

[0056] [Tables2] Ug value for furniture without profiled elements (hc onv = 10 W / m².K) Ug value for furniture with profiled elements (hconv = 3 W / m².K) Emissivity of glazing = 0.84 1.30 1.19 Emissivity of glazing = 0.03 1.26 0.99

[0057] The profiles alone reduce the Ug thermal transmittance coefficient by 0.11 W / m².K, and the low-emissivity coating alone reduces it by 0.04 W / m².K. It is observed that the combination of the profiles and the low-emissivity coating reduces the Ug by 0.31 W / m².K. This combination provides an unexpected synergy whose effect is greater than the sum of each reduction in the Ug thermal transmittance coefficient when considering the profiles alone and the second low-emissivity coating alone (profiles considered separately from the second low-emissivity coating, i.e., 0.11 + 0.04 = 0.15). The unit of the invention ultimately generates energy savings in the operation of the refrigerated unit.

Claims

Demands

1. Closed refrigerated cabinet (1) comprising at least one closing opening (2) including at least one insulating glazing (20), and an air curtain system (3) adapted to produce an air curtain (30) inside the cabinet and in the immediate vicinity of the insulating glazing (20), the insulating glazing (20) comprising at least two glass substrates (21, 22) separated by at least one gas layer (23), having a front face facing the external environment of the cabinet and a rear face in contact with the interior of the cabinet and the glazing comprising a first low-emissivity coating (23') which is arranged on a face of the glazing in contact with the gas layer, characterized in that the insulating glazing (20) comprises a second low-emissivity coating (4) which is arranged on the rear face of the glazing, and the cabinet further comprises profiled elements (5) interacting with the air curtain.

2. Refrigerated cabinet according to claim 1, characterized in that the emissivity of the rear face of the insulating glazing and interior to the cabinet, having the second low emissivity coating (4), is less than 0.3, in particular less than 0.05, preferably less than 0.

03.

3. Refrigerated cabinet according to any one of the preceding claims, characterized in that the second low-emissivity coating (4) has a thickness between 50 and 150 nm.

4. Refrigerated cabinet according to any one of the preceding claims, characterized in that each of the profiled elements (5) is inclined with respect to a plane parallel to the so-called extension plane of the insulating glazing and with respect to the direction of air inlet which is parallel to the extension plane of the glazing, and each of the profiled elements (5) has two opposite end edges (52, 53), one of the edges being closer to the glazing while the other edge is further from the glazing, the inclination of each of the profiled elements is such that the end edge closest to the glazing is located on the side of the air inlet.

5. Refrigerated cabinet according to the preceding claim, characterized in that when the refrigerated cabinet (1) is vertical with vertically extending insulating glazing and the air intake direction being from bottom to top, each of the profiled elements (5) is inclined, converging towards the interior of the cabinet, and has a so-called lower edge (52) and a opposite edge called upper (53), the end edge closest to the glazing being the lower edge (52) while the upper edge (53) is furthest from the glazing, and when the refrigerated cabinet (1) is vertical with insulating glazing extending vertically and the direction of air supply being from top to bottom, each of the profiled elements (5) is inclined converging towards the interior of the cabinet and has an edge called lower (52) and an opposite edge called upper (53), the end edge closest to the glazing being the upper edge (53) while the lower edge (52) is furthest from the glazing.

6. Refrigerated cabinet according to any one of the preceding claims, characterized in that each of the profiled elements (5) is inclined with respect to the so-called extension plane of the glazing at an angle between 20 and 30°, preferably of the order of 25°.

7. Refrigerated cabinet according to any one of the preceding claims, characterized in that each of the profiled elements (5) extends longitudinally and has a flat or substantially flat section.

8. Refrigerated cabinet according to any one of the preceding claims, characterized in that each of the profiled elements (5) is at a distance from the insulating glazing between 2 and 50 mm, preferably between 2 and 20 mm, in particular each of the profiled elements being inclined so as to have a point furthest from the glazing which is at most 50 mm.

9. Refrigerated cabinet according to any one of the preceding claims, characterized in that each of the profiled elements (5) comprises fixing parts (54) which project from a so-called longitudinal face (51) of the profiled element, in particular, each of the profiled elements (5) extending longitudinally while the fixing parts (54) are located at the terminations of the profiled element or located at different places along the profiled element.

10. Refrigerated cabinet according to any one of the preceding claims, characterized in that the opening (2) comprises a frame (2') around the insulating glazing (20) and the cabinet (1) comprises shelves (1'), the profiled elements being fixed to the glazing and / or the frame and / or the shelves.

11. Refrigerated cabinet according to any one of the preceding claims, characterized in that each of the profiled elements (5) is made of transparent glass and / or transparent plastic material such as polymethyl methacrylate.

12. Refrigerated cabinet according to any one of the preceding claims, characterized in that it is positive or negative cold and forms a vertical cabinet.

13. Use in a closed refrigerated cabinet (1) with a closing door (2), of insulating glazing (20) forming the closing door and comprising in combination a low-emissivity coating (4) arranged on the face of the insulating glazing, which is in contact with the interior of the cabinet, and profiled elements (5) arranged in the immediate vicinity of the insulating glazing, preferably substantially inclined with respect to it, to reduce the total heat transfer coefficient H such that it is less than 5 W / m2.K, and even less than 4 W / m2.K.

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