Air ventilation system, recreational vehicle having same and air ventilating method

Abstract

An air ventilation system (10) for a recreational vehicle (20) is provided. The system (10) comprises a first air ventilation unit (30) comprising a refrigerant evaporator (32) and a pair of first flaps (34) configured to fluidly connect the refrigerant evaporator (32) to an inside (22) of the recreational vehicle (20) and ambient air (24). The system (10) further comprises a second air ventilation unit (40) comprising a refrigerant condenser (42) and a pair of second flaps (44) configured to fluidly connect the refrigerant condenser (42) to the inside (22) of the recreational vehicle (20) and ambient air (70b). The first pair of flaps (34) and the second pair of flaps (44) are configured to transport heat via the refrigerant evaporator (32) from the inside (22) of the recreational vehicle (20) in a first operation mode and to transport heat via the refrigerant condenser (42) to the inside (22) of the recreational vehicle (20) in a second operation mode. Also provided are a recreational vehicle (20) having the system (10) and a method for ventilating air in a recreational vehicle (20).

Description

[0001] AIR VENTILATION SYSTEM, RECREATIONAL VEHICLE HAVING SAME AND AIR VENTILATING METHOD

[0002] This invention relates to an air ventilation system, a recreational vehicle with such an air ventilation system and a method for ventilating air in a recreational vehicle.

[0003] In general, confined spaces in which persons are expected to spend their time, have to be provided with ventilation units to ensure an appropriate supply with warm respectively cold air for the persons within the confined space. Any confined space that at least temporarily accommodates persons and has an air volume that needs to be supplied with warm respectively cold air is encompassed by the present invention. Examples of such confined spaces may be the inside of a building as a whole, the respective rooms of a building or the inside of any kind of transportation means, such as planes, trains or vehicles. In particular though, this holds for relatively limited confined spaces as it is the case for example in recreational vehicles like campers, caravans or mobile homes. Supplying a confined space with warm respectively cold, i.e. , conditioned air, is usually done with an airconditioning unit, AC, configured to heat up or cool down an air stream that passes through it. The AC can be switched between heating and cooling, but usually is optimized for cooling. Further, in order to get a good and complete temperature distribution by a conditioned air flow, the cold air flow should be let in at the top of the volume. For heating it is the other way around, i.e., the AC should be arranged at the bottom of the confined space to get a good distribution of warm air inside the confined space. So far, the known air conditioning units have thus been optimized for on one of two possible modes, i.e., either cooling or heating. Switching the ACs to the other mode then comes at the cost of reduced performance respectively higher energy consumption.

[0004] In view of this problem, it is the scope of the present invention to provide an air conditioning system which allows both heating and cooling of a confined space, in particular the confined space of a recreational vehicle, while the performance of the air conditioning system is not reduced when switching between heating and cooling.

[0005] This scope is achieved by the air ventilation system according to claim 1 . Preferable modifications thereof are presented in the dependent claims. While the invention is presented in the following for the inside of a recreational vehicle, it is to be understood that the invention is just as well applicable to any kind of confined space that has to be supplied with conditioned air. Hence, the following example of an recreational vehicle is not restricting the possible scope of the invention. According to a first aspect of the present invention, an air ventilation system for a recreational vehicle like a camper, a caravan or a mobile home, is provided. The air ventilation system comprises a first air ventilation unit comprising a refrigerant evaporator and a pair of first flaps. The first pair of flaps are configured to fluidly connect the refrigerant evaporator to an inside of the recreational vehicle and ambient air. The first air ventilation unit may have openings to provide a fluid passage between the inside of the recreational vehicle and ambient air. The inside of the recreational vehicle may be a confined space of the recreational vehicle filled with air of certain conditions, such as temperature, oxygen level and / or humidity. Ambient air may be any air surrounding the recreational vehicle. The first air ventilation unit may be configured to guide an airflow from the inside of the recreational vehicle to ambient air and vice versa. The refrigerant evaporator forms part of a refrigerant cycle of the recreational vehicle and is configured to evaporate a refrigerant liquid flowing therethrough. Evaporating, i.e., changing the phase state of the refrigerant liquid from fluid to gaseous, requires an amount of heat which is taken from the air flowing through the first air ventilation unit and is delivered to the refrigerant liquid by the evaporator. In other words, after passing the refrigerant evaporator, the air flowing through the first air ventilation unit is cooled down. The first pair of flaps may be arranged adjacent to the openings of the first air ventilation unit and may be movable to cover respectively uncover said openings such that a fluid passage for air flowing through the first air ventilation in a specific direction is provided.

[0006] The air ventilation system further comprises a second air ventilation unit comprising a refrigerant condenser and a pair of second flaps configured to fluidly connect the refrigerant condenser to the inside of the recreational vehicle and ambient air. The second air ventilation may be designed and arranged analogously to the first air ventilation unit. The second air ventilation unit may be positioned at a different location than the first air ventilation unit. For example, the first air ventilation unit may be positioned on a roof of the recreational vehicle, while the second air ventilation unit may be positioned on a floor of the recreational vehicle. Other arrangements of the first and second air ventilation unit are also possible. The refrigerant condenser forms part of a refrigerant cycle of the recreational vehicle and is configured to condense a refrigerant liquid flowing therethrough. Condensing, i.e., changing the phase state of the refrigerant liquid from gaseous to fluid, requires an amount of heat which is taken from the refrigerant liquid and is delivered to the air flow flowing through the second air ventilation unit by the refrigerant condenser. In other words, after passing the refrigerant condenser, the air flowing through the second air ventilation unit is heated up. The first and second air ventilation unit may form a split air conditioning unit, wherein the evaporator unit and the condenser unit are separated and arranged spaced apart from each other and form a refrigerant cycle. The evaporator unit and the condenser unit are connected by a refrigerant connection. A refrigerant compressor may be arranged in one of the first or the second air ventilation unit. Likewise, the pair of second flaps may be designed and arranged analogously to the first pair of flaps. The first pair of flaps and the second pair of flaps are configured to transport heat via the refrigerant evaporator from the inside of the recreational vehicle in a first operation mode and to transport heat via the refrigerant condenser to the inside of the recreational vehicle in a second operation mode. The first pair of flaps are thus controllable such that in the first operation mode air from the inside of the recreational vehicle is cooled down by the refrigerant evaporator and transported back to the inside of the recreational vehicle. Likewise, the second pair of flaps are controllable such that in the first operation mode ambient air may be heated up by the refrigerant condenser but is not transported to the inside of the recreational vehicle. Instead, said heated air is transported back to the surrounding of the recreational vehicle. As a consequence, the inside of the recreational vehicle is cooled down.

[0007] Analogously, in the second operation mode the first pair of flaps are controllable such that ambient air may be cooled down by the refrigerant evaporator but is not transported to the inside of the recreational vehicle. Instead, said cooled air is transported back to the surrounding of the recreational vehicle. Likewise, in the second operation mode, the second pair of flaps are controllable such that air from the inside of the recreational vehicle is heated up by the refrigerant condenser and is transported back to the inside of the recreational vehicle. As a consequence, the inside of the recreational vehicle is heated up.

[0008] With the first and second air ventilation unit operating in the first and second operation mode, a heat-pump for the recreational vehicle is created. Specifically, the first pair of flaps optimize the first air ventilation unit for cooling and the second pair of flaps optimize the second air ventilation unit for heating. Additionally, a split AC unit is created, wherein the evaporator unit and the condenser unit are separated apart and can be placed at optimal positions for cooling respectively heating. Consequently, the air ventilation system provides for an optimal cooling as well as heating of the inside of the recreational vehicle and at the same time works efficiently in both operation modes.

[0009] Preferably, in the first operation mode the first pair of flaps is configured to fluidly connect the refrigerant evaporator to the inside of the recreational vehicle and the second pair of flaps is configured to fluidly connect the refrigerant condenser to ambient air. In this optimized cooling mode, it is ensured that the inside air of the recreational vehicle is properly cooled, while at the same time no heated air is guided inside the recreational vehicle. This configuration improves the cooling efficiency of the system.

[0010] Preferably, in the second operation mode the first pair of flaps is configured to fluidly connect the refrigerant evaporator to ambient air and the second pair of flaps is configured to fluidly connect the refrigerant condenser to the inside of the recreational vehicle. In this optimized heating mode, it is ensured that the inside air of the recreational vehicle is properly heated, while at the same time no cooled air is guided inside the recreational vehicle. This configuration improves the heating efficiency of the system. Preferably, in a third operation mode of the air ventilation system the first pair of flaps is configured to fluidly connect the refrigerant evaporator to the inside of the recreational vehicle and the second pair of flaps is configured to fluidly connect the refrigerant condenser to the inside of the recreational vehicle. In this optimized dry mode, cabin air from the inside of the recreational vehicle transporting a lot of humidity is cooled down at the refrigerant evaporator and hence its humidity level drops. At the same time the such cooled air is heated up at the refrigerant condenser and hence a pleasant temperature is kept inside the recreational vehicle. This configuration improves the drying efficiency of the system.

[0011] Preferably, in a fourth operation mode at least one of the first pair of flaps and the second pair of flaps is configured to fluidly connect the inside of the recreational vehicle to ambient air. In this optimized air-inlet mode the at least one of the first and second air ventilation unit provides a fluid passage such that ambient air can be transported into the inside of the recreational vehicle. Thus, the inside of the recreational vehicle can be provided with fresh ambient air. Alternatively or additionally, an overheating or undercooling of the inside of the recreational vehicle can be avoided.

[0012] Preferably, the system further comprises a sensor to measure a parameter indicative of the air quality of the inside of the recreational vehicle. The first pair of flaps and the second pair of flaps are operated depending on the measurement of the sensor. The sensor may be any electronic device capable of detecting at least one parameter. There may be a variety of sensors configured to measure a variety of parameters and / or a variety of different values of the same parameter. The parameter indicative of the air quality inside the recreational vehicle may be indicative of at least one of an air temperature inside the recreational vehicle, an air humidity inside the recreational vehicle, an air pressure inside the recreational vehicle, an oxygen level inside the recreational vehicle or a carbon monoxide level inside the recreational vehicle. With the sensor, operation of the air ventilation system may be optimized to the needs of a user of the system and / or to meet any kind of security standards. For example, the sensor may detect an air temperature inside the recreational vehicle below a predetermined temperature threshold set by the user. Then the second pair of flaps may be controlled to fluidly connect the refrigerant condenser to the inside of the recreational vehicle as well as to ambient air. The fresh ambient air flowing to the inside of the recreational vehicle may be heated up correspondingly. In another example, the sensor may detect an oxygen level inside the recreational vehicle below a predetermined oxygen threshold according to security standards. Then the first and the second pair of flaps may both be controlled to fluidly connect the inside of the recreational vehicle to ambient air. The fresh ambient air flowing to the inside of the recreational vehicle may thus be enriched with oxygen.

[0013] Alternatively or additionally to the above, the first and second pair of flaps may be operated independently of the operation of the refrigerant evaporator and / or condenser. For example, the first and / or second pair of flaps may be controlled by a control unit of the recreational vehicle to route fresh ambient air inside and / or outside the recreational vehicle even if the first respectively second air ventilation unit is currently not running. This enables to purge the recreational vehicle in case of an emergency, for example when a leakage of flammable refrigerant is detected (by the sensor). In such a case, the first and second air ventilation units will not be operable properly due to the refrigerant leakage. With the inventive concept, the inside of the recreational vehicle can nevertheless be fluidly connected to ambient air. It is to be understood that other emergency situations can also be prevented, such as an accumulation of gas inside the recreational vehicle.

[0014] Preferably, the first air ventilation unit is arranged outside the recreational vehicle and is fluidly connected to a third air ventilation unit arranged inside the recreational vehicle. The first air ventilation unit may be fluidly connected to ambient air while the third air ventilation unit may be fluidly connected to the cabin air inside the recreational vehicle. The first pair of flaps may be configured to cover and uncover the fluid connection between the first air ventilation unit and the third air ventilation unit. Alternatively or additionally, the first pair of flaps may be configured to cover and uncover the fluid connection of the first air ventilation unit with ambient air and the fluid connection of the third air ventilation unit with the inside of the recreational vehicle. Arranging the first air ventilation unit outside the recreational vehicle has the advantage that the in general noisy evaporator unit of the split AC is removed from the inside of the recreational vehicle. Thus, the noise level inside the recreational vehicle is reduced.

[0015] Preferably, the system further comprises refrigerant pipes fluidly connecting the first air ventilation unit and the second air ventilation unit. The pipes transport refrigerant fluid between the refrigerant evaporator, the refrigerant condenser and the refrigerant compressor. Hence, a refrigerant cycle is formed by the refrigerant pipes. By providing the refrigerant pipes, the first air ventilation unit and the second air ventilation unit can be positioned freely on the recreational vehicle. Thus, adjustability of the air ventilation system is improved.

[0016] Preferably, the system further comprises a pipe system fluidly connected to the second air ventilation unit and extending at least partly inside the recreational vehicle. The pipe system may be configured to distribute the heated air from the refrigerant condenser inside the recreational vehicle. For example, the pipe system may extend along a floor and / or underneath a table of the recreational vehicle. The pipe system improves the heating efficiency of the system.

[0017] Preferably, the system further comprises additional heating means fluidly connected to at least one of the first air ventilation unit and the second air ventilation unit. The additional heating means may be directly connected to the first respectively second air ventilation unit. For example, the first respectively second air ventilation unit may have an opening to which the additional heating means are attached. Alternatively, the additional heating means may be indirectly connected to the first respectively second air ventilation unit. For example, the additional heating means may be integrated into a pipe system fluidly connected to the first respectively second air ventilation unit. The additional heating means further improve the heating performance of the system.

[0018] Preferably, the additional heating means comprise a heat exchanger arranged inside the second air ventilation unit and fluidly connected to the refrigerant condenser. A heat exchanger is any device which transfers heat, i.e., thermal energy, from a thermal source to a working fluid. The heat exchanger may be incorporated into a housing of the second air ventilation unit and may be directly or indirectly connected to the refrigerant condenser. The heat exchanger enables to use the air heated up by the refrigerant condenser for an additional heating purpose. Hence, the usability of the system is improved.

[0019] Preferably, the heat exchanger is fluidly connected to a water tank for providing warm water and / or hot air to the inside of the vehicle. The water tank may provide warm water to water taps, a shower and / or additional water facilities inside the recreational vehicle. Alternatively or additionally, the water tank may store thermal energy for heating up the inside of the recreational vehicle. The heat exchanger may transfer heat produced at the refrigerant condenser to water stored inside the warm water tank. The heat may be transferred via heat pipes or comparable heat transfer arrangements. With the heat exchanger and the warm water tank, the air ventilation system can also be used for providing warm water to the recreational vehicle. Hence, the efficiency of the system is further improved.

[0020] Preferably, the heat exchanger and / or the water tank are retrofittable to the system. For example, the second air ventilation unit may be provided with an insert for the heat exchanger. Alternatively or additionally, the second air ventilation unit may be provided with an outlet for fluidly connecting the water tank thereto. By retrofitting the heat exchanger and / or the warm water tank, the air ventilation system can be customized according to the user’s needs.

[0021] Preferably, the heat exchanger is operable in the first operation mode of the system. The first operation mode of the system is the cooling mode in which the second pair of flaps are controllable such that ambient air may be heated up by the refrigerant condenser and may be transported back to the surrounding of the recreational vehicle. With the heat exchanger, said heated air may be used for additional heating purposes even when heat is transported from the inside of the recreational vehicle.

[0022] Preferably, the additional heating means comprise a heating device arranged in the inside of the recreational vehicle and fluidly connected to the refrigerant condenser. The heating device may be any electrical device configured to produce heat. The heating device may be arranged adjacent to the second air ventilation unit, respectively the refrigerant condenser. Alternatively or additionally, the heating device may be arranged spaced apart from the refrigerant condenser and fluidly connected thereto via heat pipes or the like. The air heated up by the refrigerant condenser may be provided to the heating device. The heating device may be used to additionally heat up the inside of the recreational vehicle, for example in harsh winter conditions.

[0023] Preferably, the heating device is operated electrically or by gas. The heating device may be provided with air heated up by the refrigerant condenser and may further heat up said air to raise the temperature inside the recreational vehicle. By operating the heating device electrically or by gas, the system can be customized according to the user’s needs.

[0024] Preferably, the system further comprises a pipe system fluidly connected to the second air ventilation unit and extending at least partly to the inside of the recreational vehicle. The additional heating means comprise a plurality of heating devices arranged inside the pipe system and fluidly connected to the refrigerant condenser. The pipe system may be configured to distribute the heated air from the refrigerant condenser inside the recreational vehicle. For example, the pipe system may extend along a floor or underneath a table of the recreational vehicle. The pipe system may consist of a plurality of fluidly connected pipes. Each of the plurality of heating devices may be arranged inside one of the plurality of pipes accordingly. Alternatively, the pipe system may consist of a single pipe, whereas the plurality of heating devices may be arranged inside said pipe one after another. By arranging a plurality of heating devices inside the pipe system, the heating efficiency of the system is improved.

[0025] According to a second aspect of the present invention, a recreational vehicle, in particular a camper, caravan or mobile home, comprises the above described air ventilation system.

[0026] Thus, it is possible to take advantage of the above described technical effects achieved with the air ventilation system in a recreational vehicle.

[0027] According to a third aspect of the invention, a method for ventilating air in a recreational vehicle is provided. The method comprises the steps of attaching a first air ventilation unit to the recreational vehicle, the first air ventilation unit comprising a refrigerant evaporator and a pair of first flaps configured to fluidly connect the refrigerant evaporator to an inside of the recreational vehicle and ambient air; and attaching a second air ventilation unit to the recreational vehicle, the second air ventilation unit comprising a refrigerant condenser and a pair of second flaps configured to fluidly connect the refrigerant condenser to the inside of the recreational vehicle and ambient air.

[0028] The first pair of flaps and the second pair of flaps are controlled in a first operation mode to transport heat via the refrigerant evaporator from the inside of the recreational vehicle. The first pair of flaps and the second pair of flaps are further controlled in a second operation mode to transport heat via the refrigerant condenser to the inside of the recreational vehicle. The first and second air ventilation units are formed as described with respect to the first aspect of the invention. Likewise, the first and second air ventilation units are configured to perform the method steps of the third aspect of the present invention. Thus, the technical effects described with regard to the first aspect are also applicable for the method according to the third aspect.

[0029] As said above, the invention is applicable to any kind of confined space, such as the inside of buildings, specific rooms of a building, the cabin of a plane or the carts of a train. All of the above described features are suited to provide for the technical effects with arbitrarily delimited air volumes, independent of the particular application context. Hence, the above and in the following described specific embodiment of an recreational vehicle does not limit the application possibilities of the present invention in any way. Rather, the specific embodiment of a recreational vehicle serves as an illustrative example of the general inventive concept.

[0030] The above and other features of the invention will become more apparent from the following detailed description of preferred, non-limiting exemplary embodiments of the present invention, with reference to the accompanying drawings, in which:

[0031] Fig. 1 is a generic overview of an air ventilation system for a recreational vehicle according to one exemplary embodiment of the present invention;

[0032] Fig. 2 shows the system of Fig. 1 in a first operation mode;

[0033] Fig. 3 shows the system of Fig. 1 in a second operation mode;

[0034] Fig. 4 shows the system of Fig. 1 in a third operation mode;

[0035] Fig. 5 shows the system of Fig. 1 in a fourth operation mode;

[0036] Fig. 6 shows the system of Fig. 3 with an additional heat exchanger and a water tank;

[0037] Fig. 7 shows the system of Fig. 2 with an additional heat exchanger and a water tank;

[0038] Fig. 8 is a detailed view of the additional heat exchanger of Figs. 6 and 7

[0039] Fig. 9 shows the system of Fig. 3 with an additional heating device; and

[0040] Fig. 10 shows the system of Fig. 3 with a plurality of additional heating devices. Fig. 1 shows an air ventilation system 10 for a confined space. In the embodiment of Fig. 1 , the confined space is depicted as a recreational vehicle 20, more specifically a caravan. However, the system 10 is not limited to a recreational vehicle, but is also applicable to any other kind of confined space like e.g. a room inside a building, the cabin of an airplane, the passenger compartment of a train, a bus, a camper, a mobile home or any other kind of confined space in general. To ease discussion, it is however referred to a recreation vehicle 20 in the following.

[0041] The inside 22 of the recreational vehicle 20 is filled with air of certain conditions, such as a specific temperature, humidity respectively oxygen level. The inside 22 of the recreational vehicle 20 is a confined space in which persons are expected to spend their time. Therefore, the inside 22 has to be provided with ventilation units to adjust the air conditions such that the accommodated persons feel comfortable. In particular, the inside 22 of the recreational vehicle 20 can be fluidly connected to ambient air 24 surrounding the recreational vehicle 20 to provide for a fresh air supply. Said ambient air 24 however has to be cooled or heated, depending on the conditions inside the recreational vehicle 20 and the persons preferences.

[0042] For this purpose, the air ventilation system 10 comprises a first air ventilation unit 30 and second air ventilation unit 40. Both air ventilation units 30, 40 are fluidly connected to the inside 22 of the recreational vehicle 20 as well as to ambient air 24. Thus, an air flow between the inside 22 and ambient air 24 is provided by the first and second air ventilation units 30, 40. The air ventilation units 30, 40 are configured to change the conditions of the air of the inside 22 of the recreational vehicle 20, in particular its temperature.

[0043] To do so, the first air ventilation unit 30 comprises a refrigerant evaporator 32. The refrigerant evaporator 32 forms part of a refrigerant cycle of the recreational vehicle 20, in which a refrigerant fluid is subjected to phase transitions from fluid to gaseous and vice versa. The amount of thermal energy required for respectively becoming available in said phase transitions is used for cooling down respectively heating up an air stream fluidly connected to the refrigerant liquid. The refrigerant evaporator 32 in particular changes an aggregate state of the refrigerant liquid from fluid to gaseous. The amount of energy needed for this phase transition is taken from an air stream guided along the evaporator 32. In consequence, the temperature of said air stream drops, i.e., the air stream is cooled down by the evaporator 32.

[0044] The first air ventilation unit 30 further comprises a pair of first flaps 34 configured to fluidly connect the refrigerant evaporator 32 to the inside 22 of the recreational vehicle 20 and ambient air 24. In other words, the first pair of flaps 34 enable an air stream to pass from ambient air 24 along the refrigerant evaporator 32 to the inside 22 and vice versa. The first pair of flaps 34 can take an open position and a closed position, which will be described in detail with reference to Figs. 2 to 5. The first air ventilation unit 30 further comprises a first fan 36, first air inlets 38a, 38b and first air outlets 39a, 39b. The first air inlets 38a respectively outlets 39a are fluidly connected to ambient air 24. The first air inlets 38b respectively outlets 39b are fluidly connected to the inside 22 of the recreational vehicle 20. The first fan 36 is configured to guide an air stream entering the first air ventilation unit 30 via the first air inlets 38a, 38b towards the refrigerant evaporator 32. Further, the first fan 36 is configured to guide an air stream from the refrigerant evaporator 32 towards the first air outlets 39a, 39b, such that said air stream can leave the first air ventilation unit 30.

[0045] In the embodiment of Fig. 1 , the first air ventilation unit 30 is arranged outside the recreational vehicle 20 and hence forms an outside air unit. The first air ventilation unit 30 is fluidly connected to a third air ventilation unit 31 arranged inside the recreational vehicle. The third air ventilation unit 31 hence forms an inside air unit. The first air inlets 38b and first air outlets 39b facing the inside 22 of the recreational vehicle 20 fluidly connect said inside 22 to the third air ventilation unit 31 and also to the first air ventilation unit 30. Arranging the first air ventilation unit 30 outside the recreational vehicle 20 has the advantage that the generally noisy components such as the first fan 36 and the refrigerant evaporator 32 are not protruding into the inside 22 of the recreational vehicle 20. Therefore, the persons accommodated inside the recreational vehicle 20 are not disturbed by the working sound of these components.

[0046] For heating purposes, the second air ventilation unit 40 comprises a refrigerant condenser 42. The refrigerant condenser 42 also forms part of the refrigerant cycle of the recreational vehicle 20 and is configured to change an aggregate state of the refrigerant liquid from gaseous to fluid. The amount of energy needed taken from this phase transition is transferred to an air stream guided along the condenser 42. In consequence, the temperature of said air stream rises, i.e., the air stream is heated up by the condenser 42.

[0047] The second air ventilation unit 40 further comprises a pair of second flaps 44 configured to fluidly connect the refrigerant condenser 42 to the inside 22 of the recreational vehicle 20 and ambient air 24. In other words, the second pair of flaps 44 enable an air stream to pass from ambient air 24 along the refrigerant condenser 42 to the inside 22 and vice versa. The second pair of flaps 44 can take an open position and a closed position, which will be described in detail with reference to Figs. 2 to 5.

[0048] The second air ventilation unit 40 further comprises a second fan 46, second air inlets 48a, 48b and second air outlets 49a, 49b. The second air inlets 48a respectively outlets 49a are fluidly connected to ambient air 24. The second air inlets 48b respectively outlets 49b are fluidly connected to the inside 22 of the recreational vehicle 20. The second fan 46 is configured to guide an air stream entering the second air ventilation unit 40 via the second air inlets 48a, 48b towards the refrigerant condenser 42. Further, the second fan 46 is configured to guide an air stream from the refrigerant condenser 42 towards the second air outlets 49a, 49b, such that said air stream can leave the second air ventilation unit 40. As is depicted in Fig. 1 , the first and second air ventilation units 30, 40 are spaced apart from one another. In particular, the first air ventilation unit 30 is positioned on a roof top of the recreational vehicle 20 and the second air ventilation unit 40 is positioned on a floor of the recreational vehicle 20. Hence, air being cooled down by the refrigerant evaporator 32 of the first air ventilation unit 30 as described above is distributed on top of the air volume inside the recreational vehicle 20. The cold air falls to the ground and a good temperature distribution is achieved inside the recreational vehicle 20. Moreover, air being heated up by the refrigerant condenser 42 of the second air ventilation unit 40 as described above is distributed beneath the air volume inside the recreational vehicle 20. The hot air rises and a good temperature distribution is achieved inside the recreational vehicle 20.

[0049] The separated air ventilation units 30, 40 are connected by refrigerant pipes 50 to provide the evaporator 32 and the condenser 42 with refrigerant liquid. Moreover, a refrigerant compressor (not depicted) is arranged in one of the first and second air ventilation units 30, 40. With the evaporator 32, the condenser 42, the compressor and refrigerant pipes 50 a refrigerant cycle is formed in the recreational vehicle 20.

[0050] The air ventilation system 10 of Fig. 1 also comprises a pipe system 60 which is fluidly connected to the second air ventilation unit 40. In particular, the second air outlet 49b of the second air ventilation unit 40 is fluidly connected to an inlet of the pipe system 60 such that air heated up by the refrigerant condenser 42 is transported into the pipe system 60. The pipe system 60 is configured to transport the hot air coming from the second air ventilation unit 40 and extends along the floor of the inside 22 of the recreational vehicle 20. The pipe system 60 thus distributes the hot air inside the recreational vehicle 20.

[0051] With reference to Figs. 2 to 5, different operation modes of the air ventilation system 10 are described.

[0052] Fig. 2 shows the air ventilation system 10 of Fig. 1 in a first operation mode, a so-called cooling mode. In this operation mode the first of pair of flaps 34 and the second pair of flaps 44 are configured to transport heat via the refrigerant evaporator 32 from the inside 22 of the recreational vehicle 20.

[0053] In more detail, the first pair of flaps 34 are in an open position in which the first air inlet 38a and the first air outlet 39a fluidly connecting the first air ventilation unit 30 to ambient air 24 are covered by the first flaps 34. Likewise, in said open position, the first air inlet 38b and the first air outlet 39b fluidly connecting the first air ventilation unit 30 to the inside 22 of the recreational vehicle 20 are uncovered by the first flaps 34, i.e. , the first air ventilation unit 30 is fluidly connected to the inside 22 of the recreational vehicle 20.

[0054] In the cooling mode, the open position of the first pair of flaps 34 enables entry of cabin air 70 (depicted with solid arrows) from the inside 22 of the recreational vehicle 20 and having a certain temperature into the first air ventilation unit 30. The cabin air 70 comes in contact with the refrigerant evaporator 32 and hence is cooled down as described above to cool air 72. Said cool air 72 (depicted with dotted arrows) then re-enters the inside 22 of the recreational vehicle 20 due to the open position of the first pair of flaps 34.

[0055] On the other hand, the second pair of flaps 44 is in a closed position in the first operation mode or cooling mode depicted in Fig. 2. In the closed position of the second pair of flaps 44, the second air inlet 48a and the second air outlet 49a fluidly connecting the second air ventilation unit 40 to ambient air 24 are uncovered by the second flaps 44. Likewise, in said closed position, the second air inlet 48b and the second air outlet 49b fluidly connecting the second air ventilation unit 40 to the inside 22 of the recreational vehicle 20 are covered by the first flaps 44, i.e. , the second air ventilation unit 40 is fluidly connected to ambient air 24.

[0056] In the cooling mode, the closed position of the second pair of flaps 44 enables entry of ambient air 24 into the second air ventilation unit 40. The ambient air 24 comes in contact with the refrigerant condenser 42 and hence is heated up as described above to hot air 74. However, due to the closed position of the second pair of flaps 44, said hot air 74 (depicted with dash-dotted arrows) does not enter the inside 22 of the recreational vehicle 20. Instead, the hot air 74 is transported back to the outside of the recreational vehicle 20.

[0057] Consequently, due to the specific positions of the first and second pair of flaps 34, 44 in the first operation or cooling mode, the temperature of the cabin air 70 drops, i.e., the inside 22 of the recreational vehicle 20 is cooled down.

[0058] Fig. 3 shows the air ventilation system of Fig. 1 in a second operation mode, a so-called heating mode. In this operation mode the first of pair of flaps 34 and the second pair of flaps 44 are configured to transport heat via the refrigerant condenser 42 to the inside 22 of the recreational vehicle 20.

[0059] In more detail, the first pair of flaps 34 are in a closed position in which the first air inlet 38a and the first air outlet 39a fluidly connecting the first air ventilation unit 30 to ambient air 24 are uncovered by the first flaps 34. Likewise, in said closed position, the first air inlet 38b and the first air outlet 39b fluidly connecting the first air ventilation unit 30 to the inside 22 of the recreational vehicle 20 are covered by the first flaps 34, i.e., the first air ventilation unit 30 is fluidly connected to ambient air 24.

[0060] In the heating mode, the closed position of the first pair of flaps 34 enables entry of ambient air 24 into the first air ventilation unit 30. The ambient air 24 comes in contact with the refrigerant evaporator 32 and hence is cooled down as described above to cool air 72. However, due to the closed position of the first pair of flaps 34, said cool air 72 does not enter the inside 22 of the recreational vehicle 20. Instead, the cool air 72 is transported back to the outside of the recreational vehicle 20. On the other hand, the second pair of flaps 44 is in an open position in the second operation or heating mode depicted in Fig. 3. In the open position of the second pair of flaps 44, the second air inlet 48a and the second air outlet 49a fluidly connecting the second air ventilation unit 40 to ambient air 24 are covered by the second flaps 44. Likewise, in said open position, the second air inlet 48b and the second air outlet 49b fluidly connecting the second air ventilation unit 40 to the inside 22 of the recreational vehicle 20 are uncovered by the first flaps 44, i.e., the second air ventilation unit 40 is fluidly connected to the inside 22 of the recreational vehicle 20.

[0061] In the heating mode, the open position of the second pair of flaps 44 enables entry of cool air 72 into the second air ventilation unit 40. The cool air 72 comes in contact with the refrigerant condenser 42 and hence is heated up as described above to hot air 74. Due to the open position of the second pair of flaps 44, said hot air 74 is then transported to the inside 22 of the vehicle 20. In the embodiment of Fig. 3, the hot air 74 coming from the refrigerant condenser 42 is transported into the pipe system 60 and extends therein.

[0062] Consequently, due to the specific positions of the first and second pair of flaps 34, 44, the temperature of the cool air 72 inside the cabin rises, i.e., the inside 22 of the recreational vehicle 20 is heated up.

[0063] Fig. 4 shows the air ventilation system of Fig. 1 in a third operation mode, a so-called dry mode. In this operation mode the first of pair of flaps 34 and the second pair of flaps 44 are both in their respective open positions as described above. Hence, the first and second air ventilation unit 30, 40 are both fluidly connected to the inside 22 of the recreational vehicle 20.

[0064] In the dry mode, the open position of the first pair of flaps 34 enables to cool down cabin air 70 as described above to cool air 72 and re-entering said cool air 72 into the inside 22 of the recreational vehicle 20. Likewise, the open position of the second pair of flaps 44 enables to heat up cool air 72 from the inside 22 of the recreational vehicle 20 as described above to hot air 74 and re-entering said hot air 74 into the inside 22 of the recreational vehicle 20, in particular the pipe system 60.

[0065] Consequently, due to the specific positions of the first and second pair of flaps 34, 44, the humidity level of the cabin air 70 drops, i.e., the inside 22 of the recreational vehicle 20 is dried. At the same time, the such dried air is kept at a given temperature.

[0066] Fig. 5 shows the air ventilation system of Fig. 1 in a fourth operation mode, a so-called air-inlet mode. In this operation mode, the first of pair of flaps 34 are in their closed position and the second pair of flaps 44 are in an intermediate position. In their intermediate position, the second pair of flaps 44 are positioned such that the second air ventilation unit 40 is fluidly connected to the inside 22 of the recreational vehicle 20. Additionally, the second pair of flaps 44 are positioned such that a given amount of fresh air 76 (depicted with small dashed arrows) from outside of the recreational vehicle 20 enters the second air ventilation unit 40 and thus the inside 22 of the recreational vehicle 20. Hence, people accommodated inside the recreational vehicle can be provided with fresh air 76.

[0067] It is to be understood that in a non-depicted variant of the fourth operation or air-inlet mode also the second pair of flaps 44 could be in their closed position and the first pair of flaps 34 could be in an intermediate position as described above. In this configuration, the fresh air 76 enters the inside 22 of the recreational vehicle 20 through the first air ventilation unit 30.

[0068] As shown in Fig. 5, the air ventilation system 10 comprises an optional sensor 52. The sensor 52 is configured to measure a parameter indicative of the air quality of the inside 22 of the recreational vehicle 20. In the embodiment of Fig. 5, the sensor measures a temperature of the inside 22 of the recreational vehicle 20. In other examples, the sensor 52 measures a humidity level of the cabin air 70, an oxygen level of the cabin air 70 or a carbon monoxide level of the cabin air 70.

[0069] When the sensor 52 is present, the first and second pair of flaps 34, 44 are operated depending on the parameter measured by the sensor 52. In the embodiment of Fig. 5, the sensor 52 measures a temperature of the inside 22 of the recreational vehicle 20 and transmits the temperature to a nondepicted controller of the air ventilation system 10. If the temperature measured by the sensor 52 crosses a pre-determined threshold, the controller changes the intermediate position of the second pair of flaps 44 such that the amount of fresh air 76 entering the inside 22 of the recreational vehicle 20 is regulated accordingly. With the sensor 52, operation of the first and second pair of flaps 34, 44 can be adjusted to a user’s needs.

[0070] As described above, the proposed air ventilation system 10 provides a split air-conditioning (AC) unit for a recreational vehicle 20. The split AC unit is separated into a cooling unit (the first air ventilating unit 30 having the refrigerant evaporator 32) and a heating unit (the second air ventilating unit 40 having the refrigerant condenser 42). With the first and second pair of flaps 34, 44, the split AC unit can be optimized for both cooling and heating purposes. Moreover, due to the different operation modes (the respective open, closed and intermediate positions of the first and second pair of flaps 34, 44), the system functions as a heat pump for the recreational vehicle 20. Finally, as the evaporator 32 and the condenser 42 are also distributed between the first and second air ventilation unit 30, 40, the number of parts necessary to realize the presented concept is reduced compared to a regular AC system consisting of two fully equipped AC units. The air ventilation system 10 presented above can be optionally furnished with additional heating means, as will described with reference to Figs. 6 to 10.

[0071] Fig. 6 shows the system 10 of Fig. 3 in the second operation mode (the heating mode) in a first variation of the embodiment described above. In Fig. 6, the system 10 further comprises a heat exchanger 80 and a water tank 90.

[0072] The heat exchanger 80 is arranged inside the second air ventilation unit 40 and is fluidly connected to the refrigerant condenser 42. As depicted in Fig. 6, the heat exchanger 80 is placed inside the stream of hot air 74 coming from the condenser 42. The heat exchanger 80 is configured to transfer the thermal energy of the hot air 74 to a transport fluid such as water. The transferred heat is then usable for any thermal process.

[0073] In the embodiment of Fig. 6, the heat exchanger 80 is connected via a heat pipe 81 to a water tank 90. The water tank 90 is arranged on the inside 22 of the recreational vehicle 20 and contains a given amount of water. The heat exchanger 80 transfers thermal energy from the hot air 74 inside the second air ventilation unit 40. Said thermal energy is provided, via the heat pipe 81 , to the water tank 90 to rise the temperature of the water inside the tank 90. The heated water inside the tank 90 can then be used for cooking, cleaning, showering or any other tasks requiring hot water.

[0074] Fig. 7 shows the system 10 of Fig. 2 in the first operation mode (the cooling mode) in a second variation of the embodiment described above. In Fig. 7, the system 10 also comprises the heat exchanger 80 and the water tank 90 of Fig. 6.

[0075] In Fig. 7, the heat exchanger 80 is also arranged inside the second air ventilation unit 40 and is positioned adjacent to the refrigerant condenser 42. The heat exchanger 80 is configured to transfer heat via the heat pipe 81 to the water tank 90. The water inside the water tank 90 is heated up by the heat exchanger 80 as described above.

[0076] Due to the optimized operation of the system 10 for cooling and the arrangement of the heat exchanger 80 inside the second air ventilation unit 40, the heat exchanger 80 also works in the first operation mode (cooling mode). Hence, with the heat exchanger 80 and the water tank 90, warm water is also available when the inside 22 of the recreational vehicle 20 is cooled down.

[0077] In a further variation of the embodiment described above, the heat exchanger 80 and / or the water tank 90 are retrofittable to the air ventilation system 10, as will be described with reference to Fig. 8. Fig. 8 shows a detailed view of the heat exchanger 80 and the water tank 90 shown in Figs. 6 and 7. As shown in Fig. 8, the heat exchanger 80 is arranged inside the second air ventilation unit 40 adjacent to the refrigerant condenser 42. Thus, the heat exchanger 80 is positioned inside the heating cycle of the second air ventilation unit 40, where cool air 72 (shown with dotted arrows) from outside the second air ventilation unit 40 is heated up by the refrigerant condenser 42 to hot air 74. Said hot air 74 (shown with dash-dotted arrows) is then transported to the heat exchanger 80. The heat exchanger 80 absorbs some of the thermal energy of the hot air 74 and transports said thermal energy via the heat pipe 81 to the water tank 90. Hence, the hot air 74 loses some temperature and a stream of cabin air 70 leaves the second air ventilation unit 40.

[0078] The thermal energy taken from the stream of hot air 74 by the heat exchanger 80 is subjected to the water inside the water tank 90 to raise the temperature of said water. The heated water forms part of a warm water circuit 92 of the recreational vehicle 20.

[0079] As is depicted in Fig. 8, the heat exchanger 80 and the water tank 90 can be constructed as an upgrade kit 94. The upgrade kit 94 may contain the heat exchanger 80, the water tank 90 or both of the heat exchanger 80 and the water tank 90. The upgrade kit 94 is retrofittable to the air ventilation system 10. The second air ventilation unit 40 may comprise an upgrade slot (not depicted) to receive the heat exchanger 80 as described with reference to Figs. 6, 7 and 8.

[0080] Fig. 9 shows the system 10 of Fig. 3 in the second operation mode (the heating mode) in a third variation of the embodiment described above. In Fig. 9, the system 10 further comprises an additional heating device 82. The heating device 82 is arranged on the inside 22 of the recreational vehicle 20 and is fluidly connected to the refrigerant condenser 42.

[0081] The heating device 82 of Fig. 9 is placed inside the pipe system 60 fluidly connected to the second air ventilation unit 40. The heating device 82 is operated electrically or by gas. As is depicted in Fig. 9, the heating device 82 additionally heats up the cabin air 70 coming from the refrigerant condenser 42 to hot air 74. Said hot air 74 is then transported through the pipe system 60 and enters the inside 22 of the recreational vehicle 20. It is to be understood that the heating device 82 can be arranged arbitrarily inside the recreational vehicle 20.

[0082] Consequently, the additional heating device 82 as shown in Fig. 9 improves the heating efficiency of the air ventilation system 10, in particular in harsh winter conditions.

[0083] Fig. 10 shows the system 10 of Fig. 3 in the second operation mode (the heating mode) in a fourth variation of the embodiment described above. In Fig. 10, the system 10 further comprises a plurality of additional heating devices 84. The pipe system 60 comprises a plurality of heat pipes. Each one of the plurality of heating devices 84 is arranged inside one of the heat pipes of the pipe system 60.

[0084] The plurality of heating devices 84 are fluidly connected to the refrigerant condenser 42. The plurality of heating devices 84 are operated electrically or by gas. As is depicted in Fig. 10, the heating devices 84 additionally heat up the cabin air 70 coming from the refrigerant condenser 42 to hot air 74. Said hot air 74 is then transported further through the pipe system 60 and enters the inside 22 of the recreational vehicle 20. It is to be understood that the plurality of heating devices 84 can also be placed next to each other inside a single pipe of the pipe system 60. Other arrangements of the plurality of heating devices 84 are also possible.

[0085] Consequently, the plurality of heating devices 84 as shown in Fig. 10 improves the heating efficiency of the air ventilation system 10, in particular in harsh winter conditions.

[0086] Finally, it is highlighted that the present invention not just refers to the illustrated and described air ventilation system 10, but the present invention refers also to any kind of delimited air volume that accommodates persons and hence should be conditioned, e.g., the individual rooms of a house. In particular, the present invention refers also to recreational vehicles 20 like campers, caravans, mobile homes or any vehicle or building being provided with the air ventilation system 10. The invention also refers to a method for providing and operating the above described air ventilation system 10 in the first and second operation mode.

[0087] The above described configurations are preferred but provide merely exemplary embodiments of the present invention. Hence, the described configurations of the present invention do not limit the achieved scope of protection as defined by the appended set of claims. A skilled artisan will be able to imagine various modifications of the above described configurations without contravening the basic concept of the present invention and / or leaving the scope of protection as defined by the appended set of claims.

[0088] REFERENCE SIGNS air ventilation system vehicle / recreational vehicle inside of recreational vehicle ambient air first air ventilation unit third air ventilation unit refrigerant evaporator first pair of flaps first fan a, 38b first air inlets a, 39b first air outlets second air ventilation unit refrigerant condenser second pair of flaps second fan a, 48b second air inlets a, 49b second air outlets refrigerant pipes sensor pipe system cabin air cool air hot air fresh air heat exchanger heat pipe heating device plurality of heating devices water tank warm water circuit upgrade kit

Claims

CLAIMS1 . An air ventilation system (10) for a recreational vehicle (20), the system (10) comprising: a first air ventilation unit (30) comprising a refrigerant evaporator (32) and a pair of first flaps (34) configured to fluidly connect the refrigerant evaporator (32) to an inside (22) of the recreational vehicle (20) and ambient air (24); a second air ventilation unit (40) comprising a refrigerant condenser (42) and a pair of second flaps (44) configured to fluidly connect the refrigerant condenser (42) to the inside (22) of the recreational vehicle (20) and ambient air (70b), characterized in that the first pair of flaps (34) and the second pair of flaps (44) are configured to transport heat via the refrigerant evaporator (32) from the inside (22) of the recreational vehicle (20) in a first operation mode and to transport heat via the refrigerant condenser (42) to the inside (22) of the recreational vehicle (20) in a second operation mode.

2. The air ventilation system (10) of claim 1 , characterized in that in the first operation mode the first pair of flaps (34) is configured to fluidly connect the refrigerant evaporator (32) to the inside (22) of the recreational vehicle (20) and the second pair of flaps (44) is configured to fluidly connect the refrigerant condenser (42) to ambient air (24).

3. The air ventilation system (10) of claim 1 or 2, characterized in that in the second operation mode the first pair offlaps (34) is configured to fluidly connect the refrigerant evaporator (32) to ambient air (24) and the second pair of flaps (44) is configured to fluidly connect the refrigerant condenser (42) to the inside (22) of the recreational vehicle (20).

4. The air ventilation system (10) of any of the preceding claims, characterized in that in a third operation mode the first pair of flaps (34) is configured to fluidly connect the refrigerant evaporator (32) to the inside (22) of the recreational vehicle (20) and the second pair of flaps (44) is configured to fluidly connect the refrigerant condenser (42) to the inside (22) of the recreational vehicle (20).

5. The air ventilation system (10) of any of the preceding claims, characterized in that in a fourth operation mode at least one of the first pair of flaps (34) and the second pair offlaps (44) is configured to fluidly connect the inside (22) of the recreational vehicle (20) to ambient air (24).

6. The air ventilation system (10) of claim 5, characterized in that the system (10) further comprises a sensor (52) configured to measure a parameter indicative of the air quality of the inside (22) of the recreational vehicle (20), wherein the first pair of flaps (34) and the second pair of flaps (44) are operated depending on the measurement of the sensor (52).

7. The air ventilation system (10) of any of the preceding claims, characterized in that the first air ventilation unit (30) is arranged outside the recreational vehicle (20) and is fluidly connected to a third air ventilation unit (31) arranged inside (22) the recreational vehicle (20).

8. The air ventilation system (10) of any of the preceding claims, characterized in that the system (10) further comprises refrigerant pipes (50) fluidly connecting the first air ventilation unit (30) and the second air ventilation unit (40).

9. The air ventilation system (10) of any of the preceding claims, characterized in that the system (10) further comprises a pipe system (60) fluidly connected to the second air ventilation unit (40) and extending at least partly into the inside (22) of the recreational vehicle (20).

10. The air ventilation system (10) of any of the preceding claims, characterized in that the system (10) further comprises additional heating means (80, 82, 84) fluidly connected to at least one of the first air ventilation unit (30) and the second air ventilation unit (40).11 . The air ventilation system (10) of claim 10, characterized in that the additional heating means (80, 82, 84) comprise a heat exchanger (80) arranged inside the second air ventilation unit (40) and fluidly connected to the refrigerant condenser (42).

12. The air ventilation system (10) of claim 11 , characterized in that the heat exchanger (80) is fluidly connected to a water tank (90) for providing warm water and / or hot air to the inside (22) of the recreational vehicle (20).

13. The air ventilation system (10) of claim 11 or 12, characterized in that the heat exchanger (80) and / or the water tank (90) are retrofittable to the system (10).

14. The air ventilation system (10) of any of the claims 11 to 13, characterized in that the heat exchanger (80) is operable in the first operation mode of the system (10).

15. The air ventilation system (10) of any of claims 10 to 14, characterized in that the additional heating means (80, 82, 84) comprise a heating device (82) arranged in the inside (22) of the recreational vehicle (20) and fluidly connected to the refrigerant condenser (42).

16. The air ventilation system (10) of claim 15, characterized in that the heating device (82) is operated electrically or by gas.

17. The air ventilation system (10) of any of claims 10 to 16, characterized in that the system (10) further comprises a pipe system (60) fluidly connected to the second air ventilation unit (40) and extending at least partly into the inside (22) of the recreational vehicle (20); and that the additional heating means (80, 82, 84) comprise a plurality of heating devices (84) arranged inside the pipe system (60) and fluidly connected to the refrigerant condenser (42).

18. A recreational vehicle (20) comprising the air ventilation system (10) of any of the preceding claims.

19. A method for ventilating air in a recreational vehicle (20), the method comprising the steps of: attaching a first air ventilation unit (30) to the recreational vehicle (20), the first air ventilation unit (30) comprising a refrigerant evaporator (32) and a pair of first flaps (34) configured to fluidly connect the refrigerant evaporator (32) to an inside (22) of the recreational vehicle (20) and ambient air (24); attaching a second air ventilation unit (40) to the recreational vehicle (20), the second air ventilation unit (40) comprising a refrigerant condenser (42) and a pair of second flaps (44) configured to fluidly connect the refrigerant condenser (42) to the inside (22) of the recreational vehicle (20) and ambient air (24), characterized bycontrolling the first pair of flaps (34) and the second pair of flaps (44) in a first operation mode to transport heat via the refrigerant evaporator (32) from the inside (22) of the recreational vehicle (20); and controlling the first pair of flaps (34) and the second pair of flaps (44) in a second operation mode to transport heat via the refrigerant condenser (42) to the inside (22) of the recreational vehicle (20).

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