The present invention relates to refrigerating apparatuses, particularly refrigerators, for example for domestic use. In particular, the present invention relates to refrigerators provided with two (or more) fresh-food sub-compartments, designed to operate at different ranges of temperatures.

It is widely known that fresh foods have to be properly stored not to be spoiled and preserving their nutritional qualities. It is also widely known that different foods have different storing requirements; as an example vegetables can be better and longer preserved if they are kept at temperature near zero Celsius degrees, while cheese can be stored for relatively long periods of time at temperatures near ambient temperature (at least in a cold or temperate climate).

It is also known that most foods loose, partly or fully, their nutritional qualities if they froze (an example are, again, the vegetables) preventing the possibility of storing them in a freezer. Thus, the foods are to be stored in a fresh-food compartment of a refrigerator.

Refrigerators with two (or more) fresh-food compartments operating at different temperature have been developed, achieving an enhanced storing capability, thanks to the different storage temperature ranges, allowing for store different kinds of food in an optimal way.

Several refrigerator types with fresh-food compartments kept at different ranges of temperature have been developed. Usually, refrigerators with two fresh-food compartments have one compartment which operates in the range of temperatures typical of refrigerators (e.g., from +3°C up to +7°C), and another compartment operating in a lower range of temperatures, typically near zero Celsius degrees, typically from 0°C to +3°C.

An easy way to obtain fresh-food compartments operating at different ranges of temperature is providing one evaporator for each compartment. This solution, though ensuring good performances, increases the cost of the refrigerator to a market uncompetitive extent. Another solution is to draw cold air from a freezer provided in the refrigerator (when the refrigerator is integral with a freezer in a so-called combined refrigerator structure) and feed it to the low-temperature fresh-food compartment. This solution, using air at very low temperatures (typically from-18°C to -27°C), may damage the stored food if not properly designed and operated. A further solution may be to use one evaporator shared with the other compartment(s).

Purpose of the present invention is to provide a cost-effective refrigerator with one or more low temperature compartments, for storing food safely for relative long periods of time.

One aspect of the present invention relates to a refrigerating apparatus, particularly for home use. The refrigerator comprises a first fresh-food sub-compartment for storing fresh foods at a first range of temperatures, at least a second fresh-food sub-compartment for storing fresh foods at a second range of temperatures lower than the first range of temperatures, a panel separating the first and second fresh-food sub-compartments, an evaporator for commonly refrigerating both the first and second fresh-food sub-compartments - the evaporator being mounted at the rear of the refrigerator and being separated from the fresh-food sub-compartments by a rear panel - and a main fan, provided in a rear wall and passing through the rear panel, for sucking air from the first fresh-food sub-compartment and blowing the same in an interspace and through the evaporator to be cooled down; said air returns into the first fresh-food sub-compartment and reaches the second fresh-food sub-compartment through apertures formed by the rear panel. The refrigerating apparatus further comprises a secondary fan adapted to suck air from the first fresh-food sub-compartment and to blow it into the second fresh-food sub-compartment in order to raise the temperature thereof.

Preferred features of the method are set forth in the dependent claims.

The separation panel has a substantially step-like shape, and comprises a first horizontal portion, a second horizontal portion at a higher level compared to the first horizontal portion, and an upright portion joining the first and second horizontal portions; the secondary fan is mounted on the separation panel in correspondence of the upright portion thereof.

The separation panel comprises or is made of a thermal insulating material for thermally insulating the first fresh-food sub-compartment from the second fresh-food sub-compartment.

The rear panel has lateral apertures into the first fresh-food sub-compartment and a bottom aperture into the second fresh-food sub-compartment.

The panel is formed so as to leave at least a frontal gap and/or a rear gap between the separation panel and a refrigerating compartment door, and between the separation panel and the rear panel, respectively.

The refrigerating apparatus further comprises a control unit for activating the main fan on a regular basis, with a first frequency depending on a prescribed maximum temperature selectable by a user.

The refrigerating apparatus further comprises a first temperature sensor for detecting a temperature in the first fresh-food sub-compartment, a control unit being configured for activating the main fan upon the detection, by the first temperature sensor, of a temperature higher than a prescribed maximum temperature, selectable by a user.

The refrigerating apparatus further comprises a second temperature sensor for detecting a temperature in the second fresh-food sub-compartment, the control unit being configured for activating the secondary fan upon the detection, by the second temperature sensor, of a temperature lower than a minimum temperature.

The control unit is configured for activating the secondary fan on a regular basis, with a second frequency depending on the minimum temperature.

The control unit is configured for activating the secondary fan when a difference, sensed by the first temperature sensor between the prescribed maximum temperature and a predetermined temperature difference is equal to, or lower than the minimum temperature.

The secondary fan is so oriented that the air blown by the secondary fan at least partly stops the air blown by the main fan and out-coming from the apertures of the rear panel into the second fresh-food compartment.

The prescribed maximum temperature in the first fresh-food sub-compartment ranges from +3°C to +7°C.

The minimum temperature in the second fresh-food sub-compartment ranges from 0°C to +3°C.

A method of storing fresh foods, comprising the steps of providing a refrigerator compartment, comprising a first and a second fresh-food sub-compartments; providing a panel for separating the first and the second fresh-food sub-compartments; providing an evaporator; providing a rear panel for separating the evaporator from the first and the second fresh-food sub-compartments; providing apertures in the rear panel for allowing fluid communication between the evaporator and the first and the second fresh-food sub-compartments; providing a main fan communicating with the evaporator and the first fresh-food sub-compartment; providing a secondary fan communicating with the first fresh-food sub-compartment and the second fresh-food sub-compartments; activating the main fan for keeping the temperature of the first fresh-food sub-compartment beneath a maximum temperature, and activating the secondary fan for keeping the temperature of the second fresh-food sub-compartment above a minimum temperature.

These, and others, features and advantages of the solution according to the present invention will be better understood with reference to the following detailed description of some embodiments thereof, provided for illustrative and not restrictive purposes, to be read in conjunction with the attached drawings. In this regard, it is expressly intended that the drawings are not necessarily to scale and that, unless specified otherwise, they simply aim to conceptually illustrate the structures and procedures. In particular:

• Figure 1 shows schematically a front view of a refrigerator, shown without doors, according to an embodiment of the present invention.
• Figure 2 shows schematically a sectional view of the refrigerator of Figure 1 along line II-II.

With reference to the drawings, in Figure 1 there is shown a frontal view of a refrigerator 100, without doors, according to an embodiment of the present invention. In particular, the refrigerator 100 is a so-called combined refrigerator, being provided with a freezer compartment 105 in a same casing 110 that comprises a fresh-food compartment 115. The fresh-food compartment 115 is divided in a first fresh-food sub-compartment 120 and a second fresh-food sub-compartment 125, separated by a panel 130, preferably capable of providing thermal insulation. A main fan 135 is provided in the first fresh-food sub-compartment 120, preferably, albeit not limitatively, near the top of a rear wall 140. Embedded in the rear wall 140 and in correspondence with the main fan 135 an evaporator 145 (shown with dotted line) is provided. The evaporator 145 extends vertically for most of the height of the first fresh-food sub-compartment 120 and has a lower portion 150 located in correspondence with the second fresh-food sub-compartment 125. A secondary fan 155 is associated with the panel 130. Preferably, the panel 130 has a substantially step-like shape, with a first horizontal portion 130a, of prevalent extension, a second horizontal portion 130b, closer to the rear wall 140 and at a higher level with respect to the first panel portion 130a, and an upright portion 130c joining the first and second horizontal portions 130a and 130b. The secondary fan 155 is mounted on the panel 130 in correspondence of the upright portion 130c thereof. In alternative embodiments of the invention, not shown, the panel separating the first and second fresh-food sub-compartments may be shaped differently, for example may be flat, and the secondary fan may be mounted horizontally on it.

Figure 2 shows schematically a sectional (on an axis II-II shown in Figure 1) view of the refrigerator 100 of Figure 1. As can be seen, a rear panel 160 defines an interspace 165 with the rear wall 140 and separates the evaporator 145 from the fresh-food compartment 115. The main fan 135 passes through the rear panel 160 and reaches the interspace 165. Additionally, the rear panel 160 has a smaller width than the rear wall 140 leaving lateral apertures 170 running along the vertical sides of the rear wall 140 of the fresh-food compartment 115 for a length preferably, albeit not limitatively, corresponding to the length of the evaporator 145. The panel 160 extends, in the vertical direction, for almost the entire height of the first fresh-food sub-compartment 120, and also in an upper portion of the second fresh-food sub-compartment 125. Therefore, the lateral apertures 170 extend, for a main part thereof, in the first fresh-food sub-compartment 120 and, in a shorter part thereof, in the second fresh-food sub-compartment 125.

Another aperture 175 is defined at the lower end of the rear panel 160, still between the panel 160 and the rear wall 140, into the second fresh-food sub-compartment 125. Thanks to the lateral apertures 170 and the bottom aperture 175, a fluid communication between the evaporator 145 and the fresh-food compartment 115 is created. The aperture 175 is preferably placed in front of the secondary fan 155.

In further embodiments of the invention, not shown, the rear panel 160 may be substituted by alternative rear panels provided with holes or with a grid-like structure for creating a fluid communication between the evaporator and the fresh-food compartment 115.

Moreover, the first horizontal portion 130a of the panel 130 has such a length that leaves a frontal gap 177 between a front door 178 of the fresh-food compartment 115 and the panel 130 itself. Additionally or in alternative, a rear gap 179 can be provided between the rear panel 160 and the second horizontal portion 130b of the panel 130. Furthermore, additional apertures (not shown) may be provided in the first and second horizontal portions 130a, 130b as well as in the upright portion 130c of the panel 130.

The operation of the refrigerator 100 is managed by a refrigerator control unit 180. A first temperature sensor 185 and a second temperature sensor 190 can be provided in the first fresh-food sub-compartment 120 and in the second fresh-food sub-compartment 125, respectively, for allowing the refrigerator control unit 180 to monitor the temperatures in both the fresh-food sub-compartments 120 and 125.

Referring now to both Figure 1 and Figure 2, the operation of the refrigerator 100 will be described. The main fan 135 and the evaporator 145 are actuated by the refrigerator control unit 180 to keep the first fresh-food sub-compartment 120 below a prescribed maximum temperature T, typically selected by a user; in more detail, the prescribed maximum temperature T is typically adjustable by means of, for example, a well known in the art thermostat (not shown in figures) in a range of temperatures that goes from +3°C to +7°C. During its operation, the main fan 135 sucks air from the first fresh-food sub-compartment 120 and blows it into the interspace 165, where the air is cooled by the evaporator 145. The cooled air then partly returns into the first fresh-food sub-compartment 120 through the apertures 170 extending in first fresh-food sub-compartment 120 and partly reaches the second fresh-food sub-compartment 125 through the aperture 175 and the apertures 170 extending in second fresh-food sub-compartment 125. In this way, the temperature of the first fresh-food sub-compartment 120 is lowered until brought under the prescribed maximum temperature T selected by the user. Once such condition is reached, the evaporator 145 and the main fan 135 are the switched off.

At the same time, the temperature of the second fresh-food sub-compartment 125 is lowered. In particular, the temperature of the second fresh-food sub-compartment 125 is brought to a temperature lower than that of the first fresh-food compartment 120. In more detail, thanks to the stratification tendency of the air (cold air, being denser, is heavier, and thus stays in a lower position than warmer air) cold air tends to remain confined in the second fresh-food sub-compartment 125; in addition, cold air in the bottom of the first fresh-food sub-compartment 120 tends to fall into the second fresh-food compartment 125 through the frontal and rear gaps 177,179.

Also, due to the structural design of the second fresh-food sub-compartment 125 (which is smaller than the first fresh-food sub-compartment 120 and thermally insulated therefrom by the panel 130, the latter preferably comprising or being made of at least one high insulating material), when the refrigerator door is opened, the exchange of heat with the outside environment is smaller compared to that taking place in respect of the first fresh-food sub-compartment 120.

Furthermore, the second fresh-food sub-compartment 125 is located above the freezer compartment 105, which is at a very low temperature, so no heat enters into the sub-compartment 125 from the bottom thereof.

Nevertheless, the air reaching the second fresh-food sub-compartment 125 through aperture 175 and the lower part of apertures 170 is colder than the air reaching the first fresh-food sub-compartment 120 through the upper part of apertures 170 because the first runs along the whole evaporator 145 before leaving the interspace 165. Even when the evaporator 145 and the main fan 135 are turned off, for the above-mentioned stratification tendency, colder air (as the evaporator remains at a low temperature for a relatively long period after it is turned off) tends to flow into the second fresh-food sub-compartment 125 through aperture 175 and through the apertures 170 extending in the bottom part of rear panel 160.

The panel 130 prevents air from the two fresh-food sub-compartments 120 and 125 to mix to such an extent as to reach a common temperature (higher for the second fresh-food sub-compartment 125 and lower for the first fresh-food sub-compartment 120 than the selected values).

The refrigerator control unit 180 may also actuate the main fan 135 and the evaporator 145 periodically (e.g., using cycles of activation of a predetermined duration with a frequency dependent on the temperature selected by the user), or by monitoring the temperature in the first fresh-food sub-compartment 120 by means of the first temperature sensor 185 provided inside thereof (i.e., actuating the evaporator 145 and the main fan 135 whenever a temperature is detected that is above the prescribed maximum temperature T).

The secondary fan 155 is actuated by the refrigerator control unit 180 in such a way as to keep the temperature of the second fresh-food sub-compartment 125 within a prescribed temperature range and, in particular, above a predetermined minimum temperature Tm; in more detail, the minimum temperature Tm is typically comprised in a food-safety range of temperatures that goes from 0°C to +3°C. The secondary fan 155 sucks air from the first fresh-food sub-compartment 120 and blows it into the second fresh-food sub-compartment 125. Such air has a higher temperature than the air in the second fresh-food sub-compartment 125, for the reasons discussed above; therefore, blowing air from the first fresh-food compartment 120 into the second fresh-food compartment 125 allows raising the temperature in the second fresh-food sub-compartment 125 (to an extent that depends on the activation time of the secondary fan 155). Additionally, airflow generated by the secondary fan 155 contrasts an opposite airflow generated by actuating the main fan 135 and entering into the second fresh-food compartment 125 through the apertures 170 (at the lower portion of panel 160) and the aperture 175. Advantageously, the secondary fan 155 may be designed for generating the airflow in such a way as to at least partly or fully stop the opposite airflow coming from the interspace 165, preventing it to further cool down the second fresh-food sub-compartment 125, until its temperature has risen above the minimum temperature. In such an operating condition (both the fans 135 and 155 turned on) the air exits from the second fresh-food sub-compartment 125 through the frontal and rear gaps 177, 179. On the contrary, when the main fan 135 is off and the secondary fan 155 is actuated the air flows from the second fresh-food sub-compartment 125 into the first fresh-food sub-compartment 120 through the frontal and rear gaps 177, 179 and also through the apertures 170, after being blown backward by the secondary fan 155 into the interspace 165 through aperture 175.

The control unit may actuate the secondary fan 155 whenever a temperature equal to, or lower than the minimum temperature Tm is detected by means of the second temperature sensor 190 provided inside the second fresh-food sub-compartment 125.

Alternatively, the second fresh-food sub-compartment 125 is designed to have a temperature lower than the prescribed maximum temperature T of the first fresh food sub-compartment 120 of a fixed temperature difference ΔT (e.g., 4°C). Thus, the secondary fan can be activated periodically by the control unit 180 (i.e., using cycles of fan activation of a predetermined duration with a frequency dependent on the prescribed maximum temperature T) to prevent the temperature in the second fresh-food sub-compartment 125 from dropping below 0°C, only when the prescribed maximum temperature T of the first fresh food sub-compartment 120 is set at relatively low values (e.g., between +3 and +4°C) by the user. For example, when the prescribed maximum temperature T is set between +7 and +5°C, the temperature in the second fresh-food sub-compartment 125 stays in the range between +3 and +1°C, so the secondary fan 155 is always off. On the contrary when the prescribed maximum temperature T is set between +3 and +4°C the temperature in the second fresh-food sub-compartment 125 could drop in the range between -1 and 0°C, so the secondary fan 155 will be periodically actuated to keep it above 0°C. It should be appreciated that in this case there is no need of the second temperature sensor 190, relative wiring and corresponding circuitry in the control unit 180 to manage said second temperature sensor 190, leading to a cost reduction.

The present invention has been here described with reference to embodiments thereof, but it should be understood that various omissions, substitutions and changes in the form and details as well as other embodiments are possible without departing from the scope of the present invention; moreover, it is expressly intended that specific elements and/or method steps described in connection with any disclosed embodiment of the invention may be incorporated in any other embodiment as a general matter of design choice.