Built-in type outdoor unit for air conditioner

Abstract

 The present invention discloses an outdoor unit (10) installation system which can minimize reduction of heat exchange efficiency between adjacent outdoor units in an apartment building or commercial building in which a plurality of front suction/discharge type outdoor units for an air conditioner are installed, and which can minimize interferences between the front suction/discharge type outdoor units installed in each house of the large apartment building. The outdoor unit installation system installs a plurality of outdoor units (10) on plurality of floors.; Each of the outdoor units includes: an outdoor unit casing having one surface facing the outside opened and the other surfaces closed; a compressor (20) installed in the outdoor unit casing, for compressing a refrigerant gas supplied from an indoor unit through pipe lines; an air-cooled condenser (30) installed in the outdoor unit casing, for condensing the refrigerant gas supplied from the compressor; and a cooling fan installed in the outdoor unit casing for sucking outdoor air through the opened surface, and externally discharging air heat-exchanged in the air-cooled condenser through the opened surface. Here, discharge directions of air from the cooling fans of each outdoor unit are distant directions from the most adjacent outdoors.

Description

TECHNICAL FIELD

[0001] The present invention relates to an outdoor unit for an air conditioner, and more particularly to, a built-in type outdoor unit for an air conditioner.

BACKGROUND ART

[0002] An air conditioner implying a cooler, a heater or both of them is classified into a window type and a split type. in the case of the cooler, a split type air conditioner includes an indoor unit installed indoors for cooling a room, and an outdoor unit coupled to the indoor unit through refrigerant pipe lines and installed outdoors to contact air, for performing condensation heat exchange between outdoor air and a refrigerant gas in a condenser as a cooling medium, and supplying the condensed refrigerants to an evaporator of the indoor unit through the refrigerant pipe lines. The indoor unit is comprised of the evaporator for performing cooling heat exchange for evaporating the refrigerants and absorbing evaporation heat from indoor air, and a ventilating fan for circulating indoor air, and the outdoor unit is comprised of a compressor for compressing the refrigerant gas and supplying the compressed gas to the condenser, the air-cooled condenser for condensing the refrigerant gas supplied from the compressor, and a cooling fan for forcibly ventilating outdoor air to the air-cooled condenser to cool and condense the refrigerant gas. The compressor, the air-cooled condenser and the cooling fan of the outdoor unit are installed in an outdoor unit casing composing the outer appearance. The conventional hexahedral outdoor unit casing has an air suction unit for sucking air to the air-cooled condenser at its three sides, and an air discharge unit for externally discharging air absorbing condensation heat from the refrigerant gas by the heat exchange in the air-cooled condenser on its top surface.

[0003] However, the conventional outdoor unit for the air conditioner is restricted in installation spaces due to high density and strict environment regulations of cities, and increases civil applications due to noise and heat. Especially, in a common residential area such as large-scaled apartment buildings, the outdoor units must be installed in indoor verandas to improve the appearance and prevent noise.

[0004] In order to solve the foregoing problems, Japanese Laid-Open Patent Application 6-101873 suggests an air conditioner mounted building where an indoor unit of an air conditioner is installed indoors or adjacent to a room intended to be air-conditioned, and an outdoor unit of the air conditioner is installed outdoors, wherein an opening is formed on the outer wall or roof, a louver is installed in the opening, the outdoor unit of the air conditioner is disposed in the louver, and suction/discharge of the indoor unit is performed through a gap between louver plates.

[0005] In addition, Japanese Laid-Open Patent Application 3-213928 discloses a built-in type outdoor unit for an air conditioner including an outdoor unit main body for the air conditioner which is built in the wall and which includes a frame having the same size and thickness as t he wall, a suction hole for heat exchange air installed on the same surface as the outdoor unit main body, and a discharge hole for heat exchanged air.

[0006] However, the aforementioned conventional arts do not suggest a structure efficiently applicable to an apartment building in which a number of built-in type or front suction/discharge type outdoor units are used, but techniques of inserting an outdoor unit into a space formed on an outer wall of a building.

DISCLOSURE OF THE INVENTION

[0007] The present invention is achieved to solve the above problems. An object of the present invention is to provide an outdoor unit structure which can minimize reduction of heat exchange efficiency between adjacent outdoor units in an apartment building or commercial building in which a plurality of front suction/discharge type outdoor units for an air conditioner are installed.

[0008] Another object of the present invention is to provide an outdoor unit installation system which can minimize interferences between front suction/discharge type outdoor units installed in each house of a large apartment building.

[0009] In order to achieve the above-described objects of the invention, there is provided a built-in type outdoor unit for an air conditioner, including: a louver frame being fixedly installed on an inner wall of an opened space on an outer wall of a building, and including a plurality of louver blades; an outdoor unit casing contacting the louver frame, and having one surface facing the outside opened and the other surfaces closed ; a compressor installed in the outdoor unit casing, for compressing a refrigerant gas supplied from an indoor unit through pipe lines ; an air-cooled condenser installed in the outdoor unit casing, for condensing the refrigerant gas supplied from the compressor; and a cooling fan unit including a fan housing installed in the outdoor unit casing, and a cooling fan installed in the fan housing, for sucking outdoor air through gaps between the louver blades and the opened surface, and externally discharging air heat-exchanged in the air-cooled condenser through the opened surface and the gaps between the louver blades in the distant direction from the most adjacent outdoor unit.

[0010] Preferably, the louver frame is divided into a suction area and a discharge area, the plurality of louver blades are installed in each area, outdoor air is sucked into the outdoor unit casing through the gaps between the louver blades in the suction area and the opened surface, and heat-exchanged air is externally discharged through the opened surface and the gaps between the louver blades in the discharge area. More preferably, the suction area and the discharge area are divided in the up/down direction or the right/left direction of the louver frame. In the latter, more preferably, the suction area is adjacent to a suction area of the most adjacent outdoor unit.

[0011] In any of the cases, the cooling fan is a centrifugal cooling fan, and suction orifices of the fan housing are formed to face the top and bottom surface units of the outdoor unit casing. The centrifugal cooling fan is a sirocco cooling fan or turbo fan.

[0012] More preferably, a rotation direction of a centrifugal cooling fan motor is opposite to a rotation direction of a cooling fan motor of the most adjacent outdoor unit. The fan housing includes a diffusion unit for discharging air by the cooling fan. More preferably, a direction of the diffusion unit is opposite to a direction of a diffusion unit of a fan housing of a cooling fan of the most adjacent outdoor unit.

[0013] The cooling fan further includes an air guide unit for inducing discharged air in the distant direction from the most adjacent outdoor unit. Preferably, the air guide unit is installed between the cooling fan and the louver frame.

[0014] When air heat-exchanged in the air-cooled condenser is discharged, air can be induced by the louver blades in the distant direction from the most adjacent outdoor unit. Preferably, an open direction of the louver blades is opposite to an open direction of louver blades of the most adjacent outdoor unit.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will become better understood with reference to the accompanying drawings which are given only by way of illustration and thus are not limitative of the present invention, wherein;

Fig. 1

is a partially-cut perspective-sectional view illustrating a built-in type outdoor unit for an air conditioner in accordance with a first embodiment of the present invention;

Fig. 2

is a perspective view illustrating disassembly of the outdoor unit of Fig. 1;

Fig. 3

is a perspective view illustrating an apartment building in which the outdoor units of Fig. 1 have been installed;

Fig. 4

is a plane-sectional view illustrating discharge directions of waste air from discharge units of the outdoor units in the apartment building of Fig. 3;

Fig. 5

is a partially-cut perspective-sectional view illustrating the outdoor units of Fig. 1 installed adjacent to each other in the apartment building; and

Fig. 6

is a perspective view illustrating an apartment building in which built-in type outdoor units for an air conditioner have been installed in accordance with a second embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

[0016] A built-in type outdoor unit for a n air conditioner w here a suction unit i s formed in the lower portion and a discharge unit is formed in the upper portion will now be explained with reference to Figs. 1 and 2.

[0017] An external frame 4 is fixedly installed in an opened space linked to the outside of a building on an outer wall 2 of a residential and/or commercial building, and an internal frame 6 is fixedly installed inside the external frame 4. If necessary, the internal and external frames 4 and 6 can be incorporated. An inside area of the internal frame 6 is divided into a suction area 7a and a discharge area 7b. A plurality of louver blades 8 are installed in each area, so that fresh outdoor air can be sucked into an outdoor unit 10 through gaps between the louver blades 8 as indicated by the lower arrow of Fig. 1 and so that waste air heat-exchanged in the outdoor unit 10 can be discharged through the gaps between the louver blades 8 as indicated by the upper arrow of Fig. 1.

[0018] An open angle of the louver blades 8 is manually or electromotively controlled by using a driving device (not shown). If necessary, the louver blades 8 can be maintained in an open state at a predetermined angle by predetermining a suction/discharge direction of air.

[0019] On the other hand, the outdoor unit 10 fixedly installed at the inside of the outer wall 2 of the building to contact the external frame 4 and/or internal frame 6 includes an outdoor unit casing comprised of components of Fig. 2. In addition, outdoor unit components of Fig. 2 are installed in the outdoor unit casing.

[0020] In the outdoor unit casing, a front surface unit facing the suction area 7a and the discharge area 7b of the internal frame 6 is opened to be linked to the outside of the building. The opened front surface unit is divided into a suction unit 11 a and a discharge unit 11b to correspond to the suction area 7a and the discharge area 7b of the internal frame 6. The outdoor unit casing also includes both side units 12a and 12b formed at both ends of the front surface unit, a rear surface unit 12c formed to face the front surface unit, a bottom surface unit 14 formed at the lower ends of the front surface unit, the both side units 12a and 12b and the rear surface unit 12c, and a top surface unit 16 formed at the upper ends of the front surface unit, the both side units 12a and 12b and the rear surface unit 12c. The both side units 12a and 12b, the rear surface unit 12c, the bottom surface unit 14 and the top surface unit 16 are closed to form, preferably, a rectangular parallelepiped outdoor unit casing. A mesh shaped front grill 60 is additionally installed on the front surface unit of the outdoor unit 10 to prevent invasion of animals (for example, rats). For convenience' sake, reference numeral 60 is used for both the opened front surface unit and the front grill.

[0021] For easy transportation and installation, the outdoor unit casing can be divided into a suction casing corresponding to the suction unit 11 a, and a discharge casing corresponding to the discharge unit 11b.

[0022] A plurality of leg members 18a, 18b, 18c and 18d are externally protruded from the bottom surface unit 14. The leg members 18a, 18b, 18c and 18d are installed on the bottom of the building, for example a veranda of an apartment building, for supporting heavy load of the outdoor unit 10. Preferably, four leg members 18a, 18b, 18c and 18d are formed in consideration of the shape of the bottom surface unit 14. A leg reinforcing member 19 for coupling and reinforcing the leg members 18a, 18b, 18c and 18d is formed below the bottom surface unit 14 in the horizontal direction. The leg members 18a, 18b, 18c and 18d further include screws (not shown) for controlling height. Accordingly, when the bottom of the building, for example the veranda of the apartment building is not flat, they can stably position the outdoor unit 10. If the two leg members 18a and 18b disposed in the forward direction (toward the outer wall of the building) among the leg members 18a, 18b, 18c and 18d further include transport wheels (not shown), it is much easier to transport the heavy load outdoor unit 10.

[0023] In the suction unit 11a of the outdoor unit 10, a compressor 20 for compressing a refrigerant gas supplied from an indoor unit (not shown) to the outdoor unit 10 is installed on a compressor fastening unit 22, and an air-cooled condenser 30 for performing condensation heat exchange between the refrigerant gas supplied from the compressor 20 and outdoor air is fixedly installed on the both side units 12a and 12b and/or bottom surface unit 14 by using top covers 32a, 32b and 32c and/or side covers 34a and 34b.

[0024] As schematically shown in Fig. 2, in the air-cooled condenser 30, a plurality of condenser pipe lines are formed in a zigzag shape between a plurality of condenser fins. The structure and shape of the air-cooled condenser 30 have been publicly known, and thus detailed explanations thereof are omitted. The refrigerant gas compressed by the compressor 20 is transmitted through the pipe lines of the condenser 30, removed its condensation heat by externally-supplied air, and condensed. Here, the top covers 32a, 32b and 32c and the side covers 34a and 34b compose a wind path so that externally-supplied air cannot be supplied to the discharge unit 11 b without passing through the air-cooled condenser 30. As a result, outdoor air sucked through the gaps between the louver blades 8 in the suction area 7a is all induced along the wind path of the top covers 32a, 32b and 32c and the side covers 34a and 34b, passes through the air-cooled condenser 30, and exchanges heat with the refrigerant gas flowing through the condenser pipe lines.

[0025] Still referring to Fig. 2, in accordance with one preferred embodiment of the present invention, the air-cooled condenser 30 is formed to have a U-shaped cross-section so that outdoor air sucked through the opened front surface unit can be heat-exchanged in a large area. However, it must be recognized that the cross-section shape of the air-cooled condenser 30 can be changed into the optimum shape for the device according to intentions of the designer. In addition, the shape and structure of the top covers 32a, 32b and 32c and the side covers 34a and 34b must be appropriately changed in order to prevent air sucked through the opened front surface unit from being directly sucked to the discharge unit 11 b without being heat-exchanged.

[0026] Differently from the conventional outdoor unit sucking outdoor air through the three opened surfaces and discharging heat-exchanged waste air in the opened upper direction, the front suction/discharge type outdoor unit of the invention shows a high suction resistance due to a restricted suction area. In accordance with the preferred embodiment of the present invention, a centrifugal cooling fan 40 having a relative large air volume is installed in the discharge unit 11b. That is, the centrifugal cooling fan 40 for supplying outdoor air to the air-cooled condenser 30 through the suction area 7a and discharging - heat-exchanged waste air through the discharge area 7b is installed in the discharge unit 11 b of the outdoor unit 10. Fig. 2 illustrates a sirocco cooling fan as one example of the centrifugal cooling fan 40. The sirocco cooling fan has its suction orifices 36 face the up/down direction or the both side units 12a and 12b.

[0027] Still referring to Fig. 2, a fan supporting member for fixing the centrifugal cooling fan 40 to the outdoor unit casing is required to prevent vibrations of the fan operation from influencing the system. The supporting member includes a fan frame 42 for reinforcing and supporting the edges of the discharge unit 11 b, and a fan bracket 44 for fixedly coupling the sides of the centrifugal cooling fan 40 to the fan frame 42. The shape of the fan bracket 44 can be varied according to the installation direction of the centrifugal cooling fan 40. In addition, when the outdoor unit casing is divided into the suction casing corresponding to the suction unit 11 a and the discharge casing corresponding to the discharge unit 11b as described above, the fan frame 42 can reinforce and support the discharge casing. Reference numeral 46 denotes a fan front installed in front of the centrifugal cooling fan 40.

[0028] In addition, a control box 50 for controlling the operation of the outdoor unit 10 is installed at the inside of the rear surface unit 12c, preferably in the suction unit 11 a, and refrigerant pipe lines which the refrigerant gas evaporated in the indoor unit is sucked through, and a valve assembly 52, a path of the refrigerant pipe lines which the refrigerants condensed in the outdoor unit 10 are discharged through are installed below the control box 50.

[0029] The operational principle of the built-in type outdoor unit for the air conditioner will now be explained. First, the refrigerant gas supplied from the indoor unit through the refrigerant pipe lines of the valve assembly 52 is compressed through the compressor 20 and transmitted to the air-cooled condenser 30. Because the centrifugal cooling fan 40 is operated, air sucked through the gaps between the louver blades 8 in the suction area 7a and the front surface unit 60 of the outdoor unit casing evenly passes between the fins formed on the three surfaces of the air-cooled condenser 30 through the wind path of the top covers 32a, 32b and 32c, the both side units 12a and 12b and the side covers 34a and 34b, obtains condensation heat from the refrigerant gas flowing through the condenser pipe lines inserted between the fins, passes through the centrifugal cooling fan 40 with a high temperature, and is externally discharged through the gaps between the louver blades 8 in the discharge area 7b.

[0030] When the outdoor unit is installed on a louver frame fixedly installed on an inner wall of an opened space on an outer wall of a building, the front suction/discharge type outdoor unit can be obtained as shown in Fig. 1. In a high-rise apartment building which has become a representative lifestyle due to recent development of cities and a high-storied commercial building, the arrangement structure of adjacent houses is symmetrical. In the case that outdoor unit chambers are installed in one-side corners of the externally-opened spaces in the building in consideration of operation noises of the outdoor units and inside space applications of the building, the outdoor unit chambers of the adjacent houses are also adjacent to each other due to the symmetrical arrangement structure of the building.

[0031] Fig. 3 illustrates one example of the apartment building. Outdoor unit chambers 100 of A, C and E on each floor are installed in the right sides, and outdoor unit chambers 102 of B, D and F adjacent to A, C and E on each floor are installed in the left sides due to the symmetrical arrangement structure of the building. Therefore, the outdoor unit chambers 100 and 102 are adjacent to each other. According to the most remarkable characteristic of the present invention, discharge directions of heat-exchanged waste air discharged from the outdoor unit chambers 100 and 102 are distant directions from the most adjacent outdoor units (arrow X directions of Fig. 3). As described above, in the front suction/discharge type outdoor unit sucking fresh outdoor air to the lower portions of the outdoor unit chambers 100 and 102, and discharging heat-exchanged waste air to the upper portions of the outdoor unit chambers 100 and 102, fresh outdoor air is sucked into the outdoor unit chambers 100 and 102 through the gaps between the louver blades in the arrow Y directions, but waste air heat-exchanged in the outdoor unit chambers 100 and 102 are externally discharged through the gaps between the louver blades in the arrow X directions.

[0032] Accordingly, heat-exchanged waste air discharged from one outdoor unit is rarely re-sucked to a suction unit of the outdoor unit, a suction unit of an adjacent outdoor unit, or a suction unit of an outdoor unit on the upper floor. That is, when fresh outdoor air is not sucked through the suction unit but high temperature waste air discharged from the outdoor unit or other outdoor units is re-sucked through the suction unit, heat exchange efficiency of the air-cooled condenser is inevitably reduced, which can be solved by the present invention.

[0033] Fig. 4 illustrates one preferable example of the detailed means for achieving the above objects. A rotation direction of a centrifugal cooling fan 40a installed in the outdoor unit chamber 100 of A is opposite to a rotation direction of a centrifugal cooling fan 40b installed in the outdoor unit chamber 102 of B. Discharge directions of heat-exchanged waste air discharged from the centrifugal cooling fans 40a and 40b are distant directions from the most adjacent outdoor units, respectively, and thus waste air discharged from each outdoor unit is rarely re-sucked to the outdoor units themselves or the adjacent outdoor units. In accordance with the present invention, the outdoor unit discharges heat-exchanged waste air in the distant direction from the most adjacent outdoor unit, by using a centrifugal cooling fan (more preferably, sirocco cooling fan) having a relatively high discharge air volume, preferably over 6m/s. Even when a high-storied building wind or contrary wind blows in the arrow Z directions, waste air discharged from the outdoor unit is hardly re-sucked to the outdoor unit itself or the adjacent outdoor unit.

[0034] Fig. 5 illustrates one example of the installation structure of the outdoor units in accordance with the present invention. Here, an outdoor unit 10a of A must be installed more adjacent to a partition between A and B, but is shown more distant from the partition for convenience's sake. Referring to Fig. 5, the discharge direction of the sirocco cooling fan 40a of A is opposite to the discharge direction of the sirocco cooling fan 40b of B. For this, as shown in Fig. 4, a rotation direction of a sirocco cooling fan motor of A must be opposite to a rotation direction of a sirocco cooling fan motor of B.

[0035] In the above embodiment, the sirocco cooling fan having its orifices face the up/down direction was used as the centrifugal cooling fan. However, even if different shapes of fans are used, if air guide units for inducing discharged air in the distant directions from the most adjacent outdoor units are installed, the discharge directions of heat-exchanged waste air from the most adjacent outdoor units can be maintained opposite to each other merely by controlling the directions of the air guide units.

[0036] In order to reduce a discharge resistance of waste air discharged from the discharge unit, as shown in louver blades 8'of B of Fig. 5, the louver blades of the discharge unit can be formed in the longitudinal direction. That is, when heat-exchanged waste air is discharged, it can be induced by the louver blades in the distant direction from the most adjacent outdoor unit. Here, an open direction of the louver blades of A is opposite to an open direction of the louver blades of B.

[0037] When the discharge directions between the adjacent outdoor units are controlled, a s shown in Fig. 3, waste air discharged from one outdoor unit (for example, outdoor unit of C) is rarely sucked to the suction unit of the adjacent outdoor unit (for example, outdoor unit of D) or the adjacent outdoor unit on the upper or lower floor (for example, outdoor unit of E, F, A or B). As a result, heat exchange efficiency can be improved in the whole outdoor units installed in the apartment building.

[0038] The outdoor unit where the suction area is formed in the lower portion and the discharge area is formed in the upper portion has been explained. The same principle can also be applied to an outdoor unit where a suction area is formed in the upper portion and a discharge area is formed in the lower portion.

[0039] In addition, Fig. 6 illustrates an outdoor unit where a suction area and a discharge area are formed in the left and right sides. In the same manner, discharge directions of heat-exchanged waste air are X directions, namely distant directions from the most adjacent outdoor units, and suction directions of fresh outdoor air are Y directions. Accordingly, waste air discharged from each outdoor unit is hardly re-sucked to suction units of the outdoor units themselves, the adjacent outdoor units on the same floor, or the adjacent outdoor units on different floors. A centrifugal cooling f an, preferably a sirocco cooling fan is used as a cooling fan. The outdoor unit of Fig. 6 can obtain the same effects as the outdoor unit where the discharge area and the suction area are installed in the up/down direction. Still referring to Fig. 6, when the suction unit of one outdoor unit chamber is adjacent to the suction unit of the most adjacent outdoor unit chamber, the above effects can be maximized.

[0040] In order to omit a special air guide unit for controlling discharge directions, orifices of the sirocco cooling fan must face top and bottom surface units of an outdoor unit casing. However, in this case, the orifices do not face the suction area but are vertical to the suction area side.

[0041] In the above embodiment, the sirocco cooling fan was used as one example of the centrifugal cooling fan. However, if a turbo fan which is another example of the centrifugal cooling fan is used, the same principle can be applied. That is, waste air can be discharged in the distant directions from the adjacent outdoor units, by installing turbo fans having their orifices face the up/down direction in the adjacent outdoor units, and maintaining rotation directions of the turbo fans opposite to each other.

[0042] For convenience' sake, the centrifugal cooling fan having its orifices face the up/down direction has been exemplified. To embody technical ideas of the present invention within the range recited in the claims, waste air can also be discharged in the distant direction from the most adjacent outdoor unit, by using a centrifugal cooling fan having its orifices face both side units, and installing an appropriate shape of air guide unit.

[0043] In addition, waste air can be discharged in the distant direction from the most adjacent outdoor unit, by using a different shape of fan such as an axial fan instead of using the centrifugal cooling fan, and installing an appropriate shape of air guide unit. In the above cases, the air guide unit is installed between the cooling fan and the louver frame so that it cannot be externally shown for better appearance.

[0044] As discussed earlier, in accordance with the present invention, the outdoor unit structure can minimize reduction of heat exchange efficiency between the adjacent outdoor units in the apartment building in which the plurality of front suction/discharge type outdoor units for the air conditioner are installed. As a result, interferences are minimized between the front suction/discharge type outdoor units installed in each house of the high-rise apartment building or commercial building.

[0045] Although the preferred embodiments of the present invention have been described, it is understood that the present invention should not be limited to these preferred embodiments but various changes and modifications can be made by one skilled in the art within the spirit and scope of the present invention as hereinafter claimed.

Claims

1. A built-in type outdoor unit (10) for an air conditioner, comprising:

an outdoor unit casing installed inside a building and having one surface facing the outside opened and the other surfaces closed;

a compressor (20) installed in the outdoor unit casing, for compressing a refrigerant gas supplied from an indoor unit through pipe lines;

an air-cooled condenser (30) installed in the outdoor unit casing, for condensing the refrigerant gas supplied from the compressor (20); and

a cooling fan unit including a fan housing installed in the outdoor unit casing, and a cooling fan (40, 40a, 40b) installed in the fan housing, for sucking outdoor air through the opened surface, and for externally discharging air heat-exchanged in the air-cooled condenser (30) through the opened surface, wherein the heat-exchanged air is discharged from the opened surface in a lateral direction away from the outdoor unit (10).

2. The outdoor unit of claim 1,
wherein the cooling fan (40, 40a, 40b) is a centrifugal cooling fan, and suction orifices (36) of the fan housing are formed to face the top and bottom surface units of the outdoor unit casing.

3. The outdoor unit of claim 2,
wherein the centrifugal cooling fan (40, 40a, 40b) is a sirocco cooling fan.

4. The outdoor unit of claim 2,
wherein the centrifugal cooling fan (40, 40a, 40b) is a turbo fan.

5. The outdoor unit of any one of claims 1 to 4,
wherein the cooling fan (40, 40a, 40b) further comprises an air guide unit for guiding discharged air.

6. The outdoor unit of claim 5,
wherein the air guide unit is installed in front of the cooling fan (40, 40a, 40b).

7. An outdoor unit installation system for installing a plurality of outdoor units on each floor of a plurality of floors of a building, each built-in type outdoor unit comprising:

an outdoor unit casing installed inside the building and having one surface facing the outside opened and the other surfaces closed;

a compressor (20) installed in the outdoor unit casing, for compressing a refrigerant gas supplied from an indoor unit through pipe lines;

an air-cooled condenser (30) installed in the outdoor unit casing, for condensing the refrigerant gas supplied from the compressor (20); and

a cooling fan unit including a fan housing installed in the outdoor unit casing, and a cooling fan (40, 40a, 40b) installed in the fan housing, for sucking outdoor air through the opened surface, and for externally discharging air heat-exchanged in the air-cooled condenser (30) through the opened surface, wherein the cooling fan unit is adapted to discharge heat-exchanged air in a direction away from an open side of a most adjacent outdoor unit on a same floor.

Drawing