FIELD OF THE INVENTION

The present invention relates in general to ventilation systems for buildings. In particu lar, however, not exclusively, the present invention concerns room-based heat recovery ventilation devices and systems.

BACKGROUND

There are known room-based heat recovery ventilation systems in which there is one opening in the exterior wall of the room and a counterflow heat exchanger arranged to exchange heat between two channels extending inside the ventilation device and through the one opening. Furthermore, in some other known attempts, the ventilation device can include reversable fans for interchanging between suction and exhaust, thus cycling air in and out of the room in an alternating manner.

There are some drawbacks in the known ventilation devices especially related to the circulation of air inside the room since the air is flowing in and out of the room essen tially through a single point, that is, through the position of the opening in the exterior wall.

SUMMARY

An objective of the present invention is to provide a room-based ventilation system, such as of a building, and a building. Another objective of the present invention is that the room-based ventilation system and the building provide better circulation of air inside the room or rooms.

The objectives of the invention are reached by a room-based ventilation system and a building as defined by the respective independent claims.

According to a first aspect, a room-based ventilation system for providing ventilation to a room, such as of a building. The system comprises a first outlet channel and a second outlet channel, wherein first ends of the first and second outlet channels are adapted for connecting to room outlets, the room outlets being spaced apart at least by a first dis tance, and the first and second outlet channels, respectively, define at least one first opening to be arranged into the room. The room-based ventilation system further com prises first air flowing means arranged to cause flow of air between the first ends and the first openings, respectively, wherein the system is configured so that air is flowing, by the first air flowing means, substantially simultaneously towards the first end in one of the outlet channels and away from the first end in other one of the outlet channels. Still further, the room-based ventilation system comprises at least two heat storage ele ments arranged into the outlet channels for recovering heat from and for providing heat to air flowing in the outlet channels.

In various embodiments, the heat storage element may function, for example, so that air is blown from the hotter side, such as from inside the room, through a certain heat storage element or structure which the heats that element or structure up. Then, in addition, at least in some embodiments, at certain temperature threshold or based on timing, the air flow is reversed to regain that heat which has been stored into the element or structure, for example, by blowing air from outside (assuming here that air is cooler outside) into the room. Thus, in some embodiments, the heat storage element may be functionally static, notwithstanding the changing temperature thereof and/or the amount of heat being stored therein. The heat storage element may be of metal, for instance, which can easily store and/or release heat. The heat storage element may alternatively be of non-metal material.

Furthermore, the room-based ventilation system may, optionally, also comprise second air flowing means for causing air circulation inside the room.

The second air flowing means may be integrated into the same ventilation unit or device, such as having a housing, as one or both of the first air flowing means, or may be com prised in a separate ventilation unit or device. There may be an air circulation channel into which the second air flowing means are arranged to.

The room-based ventilation system may comprise a control unit configured to control operation of the first air flowing means, and, optionally, also the second air flowing means. The controlling may refer to regulating the amount of flow of air, such as rota tional speed of fan, and/or adjust position of nozzle or nozzles or the like, and/or con trolling the direction of the flow caused by the air flowing means.

In various embodiments, the control unit may be configured to determine and/or estimate efficiency of the system in real time, for example, in a sub-second range, or every second or so, or every minute, or every 2 or 5 minutes, using input data from the sensors, such as, from temperature and/or carbon dioxide sensors. Other sensory data may also be used, such as speed and/or power of the air flowing means. Furthermore, the control unit may be configured to control, directly or at least indirectly, the efficiency. For example, if the level of carbon dioxide in the room has increased, the system may be controlled to operate so that the level of carbon dioxide is decreased, even if this means lowering the efficiency.

In various embodiments, the room-based ventilation system may be configured to oper ate the first air flowing means cyclically, wherein said cyclically includes at least chang ing directions of air flows in the outlet channels. Thus, for example, the air can be sucked into the room via the first outlet channel and pushed out of the room via the second outlet channel for one period, and then vice versa for another period.

It is to be understood that the cyclical operation as used herein may also include periods of not operating the first air flowing means. For example, there may be one period of providing fresh air via the first outlet channel and pushing out air via the second outlet channel, and then some time, such as from more zero to few seconds or even minutes, such as 5 minutes, during which the first air flowing means are not operated, and then a time period of reversed air flow in the outlet channels. Similar applies also to the second air flowing means.

In various embodiments, the cyclical operation refers essentially to the fact that the di rection of air flow in the outlet channels is being reversed from time to time. Thus, the heat storage element in the first outlet channel sometimes encounters fresh air from out side the room and in other times said heat storage element encounters air coming from inside the room.

In various embodiments, the cyclical operation may be automatically configured to be from 8 seconds up to 40 minutes. In some embodiments, the cyclical operation may be configured to be performed with time periods in the range of 70 seconds up to 40 minutes.

Alternatively or in addition, the room-based ventilation system may comprise carbon dioxide determining means for determining amount of carbon dioxide in the room. In some embodiments, the second air flowing means may be arranged to cause air flowing in an air circulation channel of the system, and, thus, the carbon dioxide determining means may be arranged to the air circulation channel for determining the amount of carbon dioxide.

Alternatively or in addition, the room-based ventilation system may comprise tempera ture determining means arranged to determine air temperature in the first and second outlet channels at side of the first ends relative to the heat storage element. Alternatively or in addition, the room-based ventilation system may comprise humidity determining means arranged to determine air humidity in the first and second outlet channels at side of the first ends relative to the heat storage element.

In some embodiments, the time period of the cyclical operation may be selected based on the determination of at least one of the following: temperature by the temperature determining means, humidity by the humidity determining means, the amount of carbon dioxide in air in the air circulation channel. This applies, in some cases, also to the peri ods, if any, of the non-operation of the first, and optionally the second, air flowing means.

The room-based ventilation system may be configured to determine ambient tempera ture at both of the first ends, and, based on the determined ambient temperatures, control operation of the first air flowing means. This may entail providing air flow into the room via the first outlet channel if there is higher ambient temperature than the room temper ature at the first end of first outlet channel and if heating is desired. Alternatively or in addition, the determined ambient temperatures may be utilized by providing air flow into the room via the first outlet channel if there is a higher ambient temperature at the first end of first outlet channel than at the first end of the second outlet channel, and if heating is desired. Similar applies, in both cases as described above, also if the ambient temperature is lower at the first end of first outlet channel compared to the other point, and if cooling is desired.

In various embodiments, the first distance may be at least one meter, preferably at least 1.5 meters. In various embodiments, the first distance may be at most 5, or even 10 or 15 meters.

The room-based ventilation system may comprise communication means, such as wire less and/or wired communication means, arranged to transmit control and/or data signals to and from the control unit to control operation of the first air flowing means. Further more, the room-based ventilation system may be arranged to transmit control and/or data signals to and from the control unit to control operation of the second air flowing means.

In some embodiments, the first outlet channel, one of the first air flowing means, one of the heat storage elements may be comprised in a first ventilation device, and the second outlet channel, other one of the first air flowing means, other one of the heat storage elements may be comprised in a second ventilation device, wherein the first and second ventilation devices are physically separate devices. In some embodiments, the second air flowing means, and optionally the air circulation channel, may also be comprised in one of the first and second ventilation devices, or be a separate unit/device.

In some other embodiments, the first and the second outlet channels, the first air flowing means, and the heat storage elements may be comprised in a third ventilation device. Still further, the second air flowing means, and optionally the air circulation channel, may also be comprised in the third ventilation device.

In some embodiments, the third ventilation device may further comprise the second air flowing means and the air circulation channel, the air circulation channel comprising two second openings at opposite ends of the air circulation channel, and wherein the system is configured so that air is arranged to flow in the same direction at the first and second openings on same half of the third ventilation device with respect to a longitudi nal direction of the third ventilation device. Furthermore, the system may include a sec ond distance between the two second openings, wherein the second distance is at least one meter, preferably at least 1.5 meters, or even at least two meters. Furthermore, the second distance may be at most 5 meters, or even 10 or 15 meters. Alternatively or in addition, the first openings may be arranged between the at least two second openings in a longitudinal direction of the third ventilation device.

In various embodiments, the first ventilation device, the second ventilation device, and/or the third ventilation device may have the following dimensions: a longitudinal direction in the range of 0.5 meters to 5 meters, a depth direction in the range of 0.05 to 0.5 meters, and a height direction in the range 0.05 to 0.5 meters.

In some embodiments, the air circulation channel may be defined by a housing of the first, the second, or the third ventilation device. Thus, the housing may define substan tially closed volume between the ends of the air circulation channel. There may be the first and second outlet channels residing also within the housing of the ventilation de vice, and thus in some cases essentially within the circulation channel. In some other embodiments, the air circulation channel in the ventilation device may be defined by a separate conduit, such as extending through the device.

According to a second aspect, a building is provided. The building comprises one or several rooms, wherein at least one of the rooms, or the only room, comprise(s) at least two outlets in an exterior wall thereof and spaced apart by at least a first distance, and a room-based ventilation system in accordance with the first aspect, wherein the first and the second outlet channels of the room-based ventilation system are connected, prefera bly at or by the first ends thereof, to the room outlets, respectively. The present invention provides a room-based ventilation system and a building. The present invention provides advantage over known solutions in that the circulation of air inside the room is improved. The system has higher heat recovery efficiency via dynam ically adjusting the length, direction and logic of recuperative cycles. The heat storage can be used in optimal way to provide maximal possible energy savings within each recuperative cycle.

Furthermore, as efficiency may be determined in real time, by 1 second periods, using sensory input, which enables reaching very high efficiency in many cases. When people are present in the room, the heat recovery efficiency can be automatically adjusted as lowering of the level of carbon dioxide takes preference over the efficiency. Further, dynamic switching between heat recovery mode and utilising beneficial temperatures in outside by switching to simple unidirectional continuous ventilation flow enables system to postpone heating and/or cooling for significant periods of time.

Various other advantages will become clear to a skilled person based on the following detailed description.

The expression "a plurality of’ may refer to any positive integer starting from two (2), that is being at least two. The terms “first”, “second”, etc. are herein used to distinguish one element from another element, and not to specially prioritize or order them, if not otherwise explicitly stated.

The exemplary embodiments of the present invention presented herein are not to be in terpreted to pose limitations to the applicability of the appended claims. The verb "to comprise" is used herein as an open limitation that does not exclude the existence of also unrecited features. The features recited in the dependent claims are mutually freely com- binable unless otherwise explicitly stated.

The novel features which are considered as characteristic of the present invention are set forth in particular in the appended claims. The present invention itself, however, both as to its construction and its method of operation, together with additional objectives and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF FIGURES

Some embodiments of the invention are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings. Figures 1 A and IB illustrate schematically buildings in which a room-based ventilation system according to an embodiment can be utilized.

Figures 2A and 2B illustrate schematically a room-based ventilation system according to an embodiment.

Figures 3A-3C illustrate schematically a room-based ventilation system according to an embodiment.

Figures 4A-4C illustrate schematically a room-based ventilation system according to an embodiment.

Figures 5A-5C illustrate schematically a room-based ventilation system according to an embodiment.

DETAILED DESCRIPTION OF SOME EMBODIMENTS

Figures 1A and IB illustrate schematically buildings 100 in which a room-based venti lation system 50 can be utilized. As can be seen in Fig. 1 A, the building 100 may include one or several rooms in at least one floor (such as shown in Fig. 1 A) or in several floors (see Fig. IB). At least one of the rooms may, preferably, comprise an exterior wall of the building 100, that is, the opposite side of the exterior wall with respect to the room is outside the building 100. The ventilation system 50 may thus be arranged to draw in air from the outside and into the room, and also to remove air from the room and to the outside, thereby providing ventilation of the room.

Figure 1 A further illustrates that there may be at least two room outlets 110 for the room- based ventilation system 50, the room outlets 110 being spaced apart by a first distance 111. Furthermore, the first distance 111 may be at least one meter, preferably at least 1.5 meters. The first distance 111 may be at most 5 meters.

The ventilation units 10, such as comprising ventilation devices, of the system 50 may be arranged to be in connection with the two room outlets 110 having the first distance 111 therebetween. For example, first ends of the first and second outlet channels of the system 50 and/or the ventilation units 10 of the system 50 may be connected to the two room outlets 110.

Still further, alternatively or in addition, Fig. 1 A illustrates an optional separate air cir culation unit 125 or device 125 which comprise air flowing means for causing air circulation inside the room. Alternatively, the air flowing means may be integrated into one or both of the ventilation units 10 in the room.

Figures 2A and 2B illustrate schematically a room-based ventilation system 50. The system 50 may comprise a first outlet channel 11 and a second outlet channel 12, wherein first ends 15A, 15B of the first and second outlet channels 11, 12 may be adapted for connecting to room outlets 110, which preferably extend through an exterior wall/struc- ture of the building 100, the room outlets 110 being spaced apart at least by a first dis tance 111. Furthermore, the first and second outlet channels 11, 12 may, respectively, define at least one first opening 16 A, 16B to be arranged into the room. The first air flowing means 13 A, 13B, such as fan(s) or pump(s), or the like, may be arranged to cause flow of air between the first ends 15 A, 15B and the first openings 16 A, 16B, re spectively. The system 50 may be configured so that air is flowing, by the first air flow ing means 13 A, 13B, substantially simultaneously towards the first end 15 A, 15B in one of the outlet channels 11, 12 and away from the first end 15 A, 15B in other one of the outlet channels 11, 12. Still further, the room-based ventilation system 50 may comprise at least two heat storage elements 20 A, 20B arranged into the outlet channels 11, 12 for recovering heat from and for providing heat to air flowing in the outlet channels 11, 12.

The room-based ventilation system 50 may also, optionally, comprise at least one second air flowing means 14 A, such as fan(s) or pump(s), or the like, for causing air circulation inside the room. In addition, optionally, the second air flowing means 14A may be ar ranged to cause air flowing in an air circulation channel 17 of the system 50.

As can be seen in Figs. 2A and 2B, the room-based ventilation system 50 may comprise at least two separate devices, that is, a first ventilation device 121 and a second ventila tion device 122. In addition, the second air flowing means 14B may be comprised in one of the first and second ventilation devices 11, 12, or may be still a separate air circulation unit 125 or device 125, such as shown in Figs. 2A and 2B.

The room-based ventilation system 50 may preferably comprise a control unit 1000 con figured to control operation of the first air flowing means 13A, 13B. The control unit 1000 may be comprised in the first 121 or the second ventilation device 122, or be a separate unit or device. Furthermore, it is to be understood that the each of the devices 121, 122 (and also 125) may comprise a control subunit (not shown) which is at least arranged to establish communication connection and, optionally, further configured to provide control capabilities in said device. The room-based ventilation system 50 may preferably comprise communication means, such as wireless and/or wired communication means, arranged to transmit control and/or data signals to and from the control unit 1000 to control operation of the first air flowing means 13 A, 13B, and optionally the second air flowing means 14A, and/or between the units or devices 121, 122, 125 thereof and the control unit 1000.

The room-based ventilation system 50 may preferably be arranged to transmit control and/or data signals to and from the control unit 1000 to control operation of the second air flowing means 14 A.

The room-based ventilation system 50 may preferably be configured to operate the first air flowing means 13 A, 13B cyclically with time periods in the range of 8, or 70, seconds up to 40 minutes, wherein said cyclically includes at least changing directions of air flows in the outlet channels 11, 12. The cycling can provide improved net exchange efficiency for the ventilation.

The room-based ventilation system 50 may also comprise carbon dioxide determining means (not shown) for determining amount of carbon dioxide in the room. The second air flowing means 14A may be arranged to cause air flowing in an air circulation channel 17 of the system 50, and the carbon dioxide determining means may then be arranged to the air circulation channel 17.

Furthermore, the carbon dioxide determining means may further or alternatively be uti lized to detect intruders or broken windows. For example, if the room should be empty and the carbon dioxide level is still rising, it may be concluded that there is a person without a permission inside the room. On the other hand, alternatively or in addition, the carbon dioxide determining means may be utilized to detect if a window of the room is broken or left open based on the measured level of carbon dioxide.

The room-based ventilation system 50 may also comprise temperature determining means (not shown) arranged to determine air temperature in the first and second outlet channels 11, 12 at side of the first ends 15A, 15B relative to the heat storage element 20 A, 20B.

The room-based ventilation system 50 may also comprise humidity determining means (not shown) arranged to determine air humidity in the first and second outlet channels 11, 12 at side of the first ends 15 A, 15B relative to the heat storage element 20 A, 20B. Preferably, the time period of the cyclical operation may be selected based on the deter mination of at least one of the following: temperature by the temperature determining means, humidity by the humidity determining means, the amount of carbon dioxide in air in the air circulation channel 17.

The room-based ventilation system 50 may also be configured to determine ambient temperature at both of the first ends 15 A, 15B, and, based on the determined ambient temperatures, control operation of the first air flowing means 13 A, 13B. This may entail providing air flow into the room via the first outlet channel if there is higher ambient temperature than the room temperature at the first end of first outlet channel and if heat ing is desired. Alternatively or in addition, the determined ambient temperatures may be utilized by providing air flow into the room via the first outlet channel if there is a higher ambient temperature at the first end of first outlet channel than at the first end of the second outlet channel, and if heating is desired. Similar applies, in both cases as de scribed above, also if the ambient temperature is lower at the first end of first outlet channel compared to the other point, and if cooling is desired.

Regarding the dimensions of the first and second ventilation devices 121, 122 in accord ance with various embodiments, they may have the following dimensions: a longitudinal direction in the range of 0.5 meters to 1.7 meters, preferably from about two to about 1.1 meters, a depth direction in the range of 0.05 to 0.5 meters, preferably about 0.2 meters, and a height direction in the range 0.05 to 0.5 meters, preferably about 0.2 me ters.

Figures 3A-3C illustrates schematically a room-based ventilation system 50. Figs. 3A and 3B are sectional views. As can be seen, the first and the second outlet channels 11, 12, the first air flowing means 13A, 13B, and the heat storage elements 20A, 20B are comprised in a third ventilation device 123, that is, integrated into a single unit or device.

As can be seen, the longitudinal direction 19 of the device 123 is shown in Fig. 3A, however, in Fig. 3B, the longitudinal direction 19 is extending towards and/or away from the viewer. Fig. 3C shows the third ventilation device 123 from a perspective view from a viewing point inside the room. As can be seen, the ventilation device 123 may be installed above the window opening 107, if any, and to the upper part of the wall, such as even substantially to the comer between the inner surface of the exterior wall 105 and the inner surface of the ceiling 102 of the room.

As shown in Figs. 3A and 3B, for example, the ventilation device 123 may comprise a first outlet channel 11 and a second outlet channel 12. First ends 15 A, 15B of the first and second outlet channels 11, 12 are arranged for connecting to outlets 110 of the room- based ventilation system 50. The outlets 110 are spaced apart by a first distance 111. The first and second outlet channels 11, 12 respectively define at least one first opening 16A, 16B, such as being at the opposite end of the channels 11, 12 with respect to the first ends 15 A, 15B, or alternatively being at least a distance way from the first ends 15 A, 15B, such as having therebetween at least a portion of the heat storage element 20 of the device 123. Furthermore, first air flowing means 13A, 13B, such as fan(s) or pump(s), or the like, are arranged, such as selectively by controlling the operation thereof, to cause flow of air between the first ends 15 A, 15B and the first openings 16 A, 16B, respectively. Thus, air may be arranged to flow towards the first end 15 A, 15B in one of the outlet channels 11, 12 (e.g., the first channel 11 in Fig. 3A) and away from the first end in other one of the outlet channels 11, 12 (the second channel 12 in Fig. 3A).

The ventilation device 10 may further comprise the heat storage elements 20A, 20B arranged to recover heat from air flowing in the one of the outlet channels 11, 12 and to heat air flowing in the other one of the outlet channels 11, 12. Still further, the ventilation device 123 may comprise an air circulation channel 17 defining at least two second openings 18 A, 18B having a second distance 21 between them, and, optionally, com prising second air flowing means 14A, such as fan(s) or pump(s), or the like, for causing flow of air in the circulation channel 17 between the at least two second openings 18 A, 18B. As is evident based on Figs. 3A-3C, the air flows in the outlet channels 11, 12 do not, preferably, mix relative to each other within the channels 11, 12. Also, the air flow in the circulation channel 17 is separate with respect to air flows in the outlet channels 11, 12.

The ventilation device 123 may be operated so that the direction of the flows in the first and second outlet channels 11, 12 and/or in the circulation channel 17 may be changed and the flow of air increased or decreased as desired by operating the first 13 A, 13B and, optionally, second air flowing means 14A. The air flowing means 13A-14A may be controlled independently of each other by the control unit 1000 in the device 123 or by a separate control device 1000.

Furthermore, the third ventilation device 123, such as the first and second ventilation devices 121, 122 in Figs. 2A and 2B, may comprise a housing 22. The housing 22 may enclose the components of the device(s) 121-123 inside of the housing 22, or alterna tively, the housing 22 may be a cover basically hiding the components of the device 121- 123 when installed onto the inner surface of the exterior wall 105. As visible in Fig. 3C, there may be an opening or gap 23 (the opening or gap 23 is emphasized by the dashed line drawn along the inner surface of the ceiling 102), or openings, or even a nozzle or nozzles, arranged for allowing the air to flowing into and out of the outlet channels 11, 12 and the circulation channel 17.

In various embodiments, such as in the one illustrated in Figs. 3A-3C, the circulation channel 17 is defined by a separate conduit. Alternatively, the circulation channel 17 may be defined by the housing 22 of the ventilation device 123.

Optionally, the ventilation device 123 may be configured so that air is arranged to flow in the same direction at the first and second openings 16 A, 16B, 18 A, 18B on same half of the ventilation device 123 with respect to the longitudinal direction 19 of the ventila tion device 123. In the situation being illustrated in Figs. 3 A and 3C, this means that the direction of the flow is in the same direction in openings 16A and 18A with respect to each other, and in openings 16B and 18B with respect to each other. Thus, the circulation of air is being amplified within the room. In other embodiments, the direction of flows may be different.

In some preferable embodiments, the ventilation device 123 may comprise carbon diox ide determining means for determining amount of carbon dioxide in air in the circulation channel 17. The carbon dioxide determining means may be utilized to control the venti lation device 123 to provide fresh air so as to keep the level of carbon dioxide in the room low enough.

In various preferable embodiments, the ventilation device 123 may comprises tempera ture determining means arranged to determine air temperature in the first and second outlet channels 11, 12 at side of the first ends 15A, 15B with respect to the heat storage element 20. Alternatively or in addition, the ventilation device 123 may comprise hu midity determining means arranged to determine air humidity in the first and second outlet channels 11, 12 at side of the first ends 15A, 15B with respect to the heat storage element 20. The ventilation device 10 may thus be configured to operate the first air flowing means 13A, 13B and, optionally, the second air flowing means 14A, based on the temperature and/or humidity values determined by the temperature and/or humidity determining means.

In various embodiments, the ventilation device 123 may be configured to operate the first air flowing means cyclically such as described hereinbefore. The cyclic operation may include cycling for a time period in the range of 70 seconds up to 40 minutes, for instance. In some embodiments, the time period may be selected based on the determination of at least one of the following: temperature by the temperature determin ing means, humidity by the humidity determining means, the amount of carbon dioxide in air in the circulation channel 17. Thus, shorter periods may be utilized if there is not much ventilation and/or heating/cooling needed into the room. Longer periods may be utilized if there is a higher demand for the ventilation and/or heating/cooling.

Furthermore, the ventilation device 10 may be configured to determine ambient temper ature at both of the first ends 15 A, 15B, and, based on the determined ambient tempera tures, operate the first air flowing means 13 A, 13B, such as in cyclic manner. For exam ple, when the room needs heating and sun shines onto one of the outlets 110, air may be drawn in into the room from that outlet continuously (and out from the other outlet), enabling room to be heated. Further still, blowing air continuously in one direction sim ulates an open window situation. The same principle works with cooling, particularly at night time/early mornings.

Regarding the dimensions of the ventilation device 10 in accordance with various em bodiments, the second distance 21 may be at least one meter, preferably at least 1.5 meters, or even at least two meters. Furthermore, the second distance may be at most 5 meters. In various embodiments, alternatively or in addition, the third ventilation device 123 may have the following dimensions: a longitudinal direction in the range of 0.5 meters to 5 meters, preferably from about two to about 3.5 meters, a depth direction in the range of 0.05 to 0.5 meters, preferably about 0.2 meters, and a height direction in the range 0.05 to 0.5 meters, preferably about 0.2 meters.

In various embodiments, the housing 22 of the third ventilation device 123 may be ar ranged to extend across the room along the inside surface of the exterior wall 105, such as shown in Fig. 3C.

Figures 4A-4C illustrate schematically a room-based ventilation system 50. The system 50 may be substantially similar to the one shown in Figs. 3A-3C, however, in this case the air circulation channel 17 is defined by the housing 22, that is, there is not separate air circulation channel 17.

Figures 5A-5C illustrate schematically a room-based ventilation system 50. The system 50 may be substantially similar to the one shown in Figs. 3A-3C or Figs. 4A-4C, how ever, in this case essentially the opening or gap 23, such as shown in Figs. 3B, 3C, 4B, and 4C but there are openings, such as having ventilation grates or nozzle or the like, via which the air flows. Regarding the embodiments of the present invention, filters, such as air filters, may be utilized to filter the air flowing in and/or by the system 50.