JPH10122602A - Outdoor device of air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an outdoor device for an air conditioner in which an installing space can be reduced in size and its exterior characteristic can be improved. SOLUTION: In an outdoor device for an air conditioner comprising an outdoor device casing, a heat exchanger 3 arranged at the rear surface side of the outdoor device casing, a blower 4 having a rotating shaft installed at a downstream side of the heat exchanger 3 while being directed in a substantial horizontal direction and an air blowing port for blowing air from the blower 4, the air blowing port is constituted by a first air blowing port 11 for blowing air upwardly from a front part of a top plate of the outdoor device casing and a second air blowing port 12 for blowing air from a lower part of a front surface side of a outdoor device casing in a slant upward direction, resulting in that a wide air blowing grill surface at the front face of the outdoor device casing is eliminated and an air blowing direction is directed toward an upper part of the outdoor device casing as much as possible and an installing space in the front face direction can be well reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an outdoor unit for an air conditioner.

[0002]

2. Description of the Related Art Conventionally, as an outdoor unit for a general air conditioner, a blower (prope fan) having a heat exchanger on the back side in a box-shaped casing and a horizontal rotating shaft on the downstream side thereof is known. And an air blowing grille, respectively, to blow air in a substantially horizontal direction from the front side of the casing (see, for example, JP-A-8-54134).

[0003]

In the case of such an outdoor unit, the rear side of the outdoor unit can be placed close to the wall of the building.
According to the air flow suction and blow pattern, if the space on the front side in the air blow direction is narrow, the blown air is short-circuited and sucked again, resulting in a decrease in heat exchange performance.

[0004] Therefore, if there is no large space in front of the air outlet grille of the casing, proper installation cannot be performed, and there is a disadvantage that a substantially large installation area is required. In addition, the entire front side of the casing is formed as an air blowing grill, and it is necessary to provide a large number of lattice-shaped wind direction guides.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has the following means for solving the problems. ing.

That is, the outdoor unit for an air conditioner of the present invention comprises an outdoor unit casing, a heat exchanger provided on the rear side of the outdoor unit casing, and a rotary shaft downstream of the heat exchanger. In an outdoor unit for an air conditioner including a blower provided in a horizontal direction, and an air outlet for blowing air from the blower, the air outlet is provided at a front part of a top plate of the outdoor unit casing. A first air outlet for blowing air upward from the air outlet and a second air outlet for blowing air from the lower front side of the outdoor unit casing.

Therefore, the air blown out from the blower is directed upward from the first air outlet on the outdoor unit casing top plate side and to the second air outlet on the front side lower portion of the outdoor unit casing.
The air is blown outward from the air outlet of each case, and the blown air mainly flows toward the upper part of the casing. It can be installed freely without inviting a short circuit. As a result, a substantial installation space can be reduced.
In addition, it is possible to prevent air from being blown to the body of a person passing through the front side of the casing.

Further, in the outdoor unit for an air conditioner of the present invention, for example, in the above configuration, the blower is located in the outdoor unit casing and is provided in a plurality of upper and lower stages via partition walls. Another air outlet is provided diagonally above the lower fan of the upper fan on the upper side, and another air outlet obliquely above the upper side of the lower fan is provided on the lower side of the partition wall.

That is, the outdoor unit casing is formed, for example, vertically long, and has a plurality of vertically arranged blowers incorporated therein through a partition wall. In this case, the upper air outlet of the uppermost blower is also formed as the above-described first air outlet at the front of the top plate of the outdoor unit casing, while the upper air outlet of the lowermost blower is opened. The lower air outlet is formed at the lower front side of the outdoor unit casing as the second air outlet described above, and has the same effect as described above. In addition, each of the other air outlets on the lower side and the upper side via the respective partition walls between the upper and lower blowers is also formed obliquely upward. Therefore, all the air blown out from the air outlets is also blown upward, so that there is no need for a space margin on the front side of the outdoor unit casing.

In particular, in this case, the upward air flow on the lower side flows as much as possible along the front wall of the casing while maintaining the Cander effect, and the air flow on the upper side is further pushed upward ( (Deflecting) action, so that the upward air blowing action is more effectively realized.

Further, in the configuration of each outdoor unit described above, the air is blown from the first and second air outlets to the air blowing passage from the blower to the first and second air outlets. Providing a tongue for relatively adjusting and setting the amount of air blown out, and appropriately adjusting the ratio of the amount of air blown out from each of the upper first and lower second air outlets (for example, the upper part is larger, the lower part is By doing so, the above operation can be realized more effectively.

[0012] Further, the above-mentioned operation is achieved by the above-described blower, which may be a conventional axial fan whose rotating shaft is installed horizontally in the front direction of the casing, but air is blown in a centrifugal direction or an oblique direction thereof. This is particularly effective when a centrifugal fan or a mixed flow fan is employed.

[0013]

As a result, according to the outdoor unit for an air conditioner of the present invention, the installation space is as small as possible, and the exterior property is high without the necessity of forming an air blowing grill on the entire casing surface. It is possible to provide an outdoor unit.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) Figs. 1 to 3 show the configuration of an outdoor unit for an air conditioner according to Embodiment 1 of the present invention.

In FIG. 1, reference numeral 1 denotes a flat box-shaped cassette casing of the outdoor unit 2, in which a heat exchanger 3 and a centrifugal fan 4 (see FIG. 2) are disposed. The air chamber 5 is divided into a left and right space by a large-capacity blower chamber 5 and a machine room 7 in which a compressor 6 and electric parts are disposed, via a partition wall 8 extending in a slate in the front-rear direction.

A front side portion of a ceiling wall (top plate) 1a of the cassette casing 1 forming the air blowing chamber 5 includes:
A first air outlet grill 11 having a predetermined front-rear width extending in both the left and right directions corresponding to the width of the blower chamber 5, and a blower chamber 5 at a lower portion of a front wall (front plate) 1 b of the cassette casing 1. A second air blowing grille 12 having a predetermined vertical width extending in both left and right directions corresponding to the width of the cassette casing 1 further extends vertically in a substantially central portion of a side wall (side plate) 1c of the cassette casing 1 for a predetermined length. Third air blowing grill 13 having a predetermined front and rear width
Are provided.

The ceiling wall 1a of the cassette casing 1 is inclined downward to the front side, and the first air blowing grill 11 is arranged so that the wind blowing direction is slightly inclined to the front side as shown in FIG. Wind direction guide plates 11a, 11a
.. Are provided. The second air blowing grill 12 has upper and lower opening tongues (guide portions) 12a and 12b which are shaped so as to blow air obliquely upward and forward as shown in FIG. I have.

A heat exchanger fitting port 1d is formed in the back of the blower chamber 5, and a flat heat exchanger 3 is fitted to the heat exchanger fitting port 1d. And
On the downstream side, the first to third air blowing passages 10 in the vertical and right directions with respect to the cassette casing front wall 1b.
The centrifugal fan 4 is provided through a circular air suction port 14 formed at the center of a partition wall 15 forming a, 10b, and 10c. The centrifugal fan 4 is a motor 1 fixed on the rear surface of the front wall 1b of the cassette casing 1 via a stay 9 with its rotating shaft 17a directed horizontally.
7 is driven to rotate. And
Around the centrifugal fan 4, as described above, between the front wall 1 b of the cassette casing 1 and the partition wall 15 around the air suction port 14 for forming an air blowing passage, the first tongue on the side wall 1 c portion side By the part 21 and the second tongue part 22 on the partition wall 8 side,
First to third air blowing passages 10a, 10b, 10c communicating with the first to third air blowing grills 11 to 13 are formed.

The first tongue 21 and the second tongue 22 are separated from each other by, for example, the rotation angle θ of the centrifugal fan 4 in the upper first tongue.
The opening angle θ (θ ₁ =
200 to 210 °), the lower second and third air outlet passages 10b and 10c have smaller opening angles θ ₂ (θ ₂ = 160).
To 150 °), and the wind from the centrifugal fan 4 in the rotation direction M draws streamlines as indicated by arrows, passes through the first to third outlet passages 10a to 10c, Third
From the outlet grills 11 to 13 at a predetermined air volume and wind speed.

In the above configuration, the air flow blown in the centrifugal direction by the centrifugal fan 4 is generated by the first and second tongue portions 21 and 21.
The first, second, and third air outlet grills 11, 12, and 13 are passed from the first, second, and third air outlet passages 10a, 10b, and 10c at the air flow rate set by the tongue portion 22.
The air is smoothly blown upward and laterally through the airbag. In particular, the first and second air blowing grilles 11, 12
From the upper and lower positions, the air is blown almost obliquely upward and forward from the front, and even in an installation state where there is not enough room on the front side, stable air blowing form without inducing a short circuit Can be realized.

In the above configuration, the third air outlet grill 13 can be omitted. In such a case, for example, the first and second air blowing grills 11
It is appropriate that the air flow ratio between 7 and 12 is 7: 3 to 8: 2.

(Embodiment 2) FIGS. 4 to 6 show the configuration of an outdoor unit for an air conditioner according to Embodiment 2 of the present invention. This embodiment is the same as the first embodiment.
In which a centrifugal fan is replaced with a mixed flow fan.

In the figure, reference numeral 1 designates a flat box-shaped cassette casing of the outdoor unit 2 in which a heat exchanger 3 and a fan 4 are arranged as in the first embodiment. A large-capacity air-blowing chamber 5 and a machine room 7 in which a compressor 6 and electrical components are disposed are partitioned by a left and right space portion via a partition wall 8 extending in the front-back direction in a slate. I have.

On the front side of the ceiling wall 1a of the cassette casing 1 forming the blower chamber 5, there is provided a first air blow grill having a predetermined front-rear width extending in both left and right directions corresponding to the width of the blower chamber. A second air blowing grille 12 having a predetermined vertical width extending in both the left and right directions corresponding to the width of the blower chamber is provided at a lower portion of the front wall 1b of the cassette casing 1. A third portion of a predetermined front-rear width extending vertically in a central portion of the side wall 1c of
Are provided respectively.

The ceiling wall 1a of the cassette casing 1 is inclined downward to the front side, and the first air blowing grill 11 is arranged to slightly incline the wind blowing direction to the front side as shown in FIG. Wind direction plate guides 11a, 11a
.. Are provided. The second air blowing grille 12 has upper and lower opening tongues (guide portions) 12a and 12a so as to blow air obliquely upward and forward as shown in the figure.
b.

Further, a heat exchanger fitting port 1d is formed in the back surface of the blower chamber 5, and a flat heat exchanger 3 is fitted to the heat exchanger fitting port 1d. And
On the downstream side, a mixed flow fan 41 is disposed via a circular air inlet 14 formed in the center of the partition wall 15. The mixed flow fan 41 is connected to a motor 4 fixed to the rear surface of the front wall 1 b of the cassette casing 1 via a stay 9.
7 is driven to rotate. The motor 47 is provided with its rotating shaft 47a directed horizontally. Also, around the mixed flow fan 41,
Between the front wall 1b of the cassette casing 1 and the partition wall 15 around the air suction port 14, the first tongue 21 and the second tongue 22 similar to FIG. The air outlet passages 10a, 10b and 10c communicating with the third air outlet grills 11 to 13 are formed in the same manner as in the case of FIG. 3 described above.

The first tongue portion 21 and the second tongue portion 22 are separated from each other by the upper first
The opening angle θ ₁ (θ ₁ =
200 to 210 °), the lower second and third air outlet passages 10b and 10c have smaller opening angles θ ₂ (θ ₂ = 160).
To 150 °), and the wind from the mixed flow fan 41 in the rotation direction M draws a streamline as indicated by an arrow.
The air flows through the third air outlet passages 10a to 10c, and is appropriately blown from the first to third air outlet grills 11 to 13 at a predetermined air volume and speed.

With the above arrangement, the air flow blown by the mixed flow fan 41 in a state of being slightly inclined forward from the centrifugal direction is generated at the air flow rate set by the first and second tongue portions 21 and 22. 1, second and third air outlet grills 11,
The air is smoothly blown upward and laterally through the holes 12 and 13. In particular, the first and second air blowing grills 1
From the upper and lower positions, the air is blown obliquely upward and obliquely upward on the front side, so that even in an installation state where there is not enough room on the front side, stable air is generated without inducing a short circuit. Can be realized. Further, as a result, it is not necessary to form an air blowing grill on the entire front wall 1b of the cassette casing 1, so that the degree of freedom in design is increased and the exterior property is improved.

(Embodiment 3) FIGS. 7 to 9 show the configuration of an outdoor unit for an air conditioner according to Embodiment 3 of the present invention.

In this embodiment, the first embodiment described above is used.
The first and second air blow grilles 11 and 12 in the configuration of the outdoor unit are expanded to the front of the machine room 7, and the first and second air passages 10a and 10
The air outlet ends of the air outlet passages 10a and 10b are reduced as much as possible by extending and extending the air outlet end of the air outlet passage b.

In the figure, reference numeral 1 designates a flat box-shaped cassette casing of the outdoor unit 2. The inside of the cassette casing 1 is a large-volume air-blowing chamber 5 in which a heat exchanger 3 and a centrifugal fan 4 are arranged. It is partitioned by a corner-shaped partition wall 81 into two spaces on the left and right sides of the compressor room and the machine room 7 in which electric parts and the like are disposed. Unlike the first and second embodiments described above, the partition wall 81 extends from the rear side to the vicinity of the front side, and then has a hook shape bent slightly to the left with a slight radius. It is provided with an air blowing grill of a predetermined width and a ventilation passage enlarged space between the front wall 1b.

A first air outlet grill 11 having a predetermined front-rear width extending to both right and left ends of the entire cassette casing 1 is provided at a front portion of the ceiling wall 1a of the cassette casing 1 forming the blower chamber 5. A second air blowing grille 12 having a predetermined vertical width and extending to both left and right ends of the entire cassette casing 1 is further provided at a lower portion of the front wall 1b of the cassette casing 1.
A third air blowing grille 13 having a predetermined front-rear width extending in the vertical direction for a predetermined length is provided at a central portion of the side wall 1c.

The ceiling wall 1a of the cassette casing 1 is inclined downward to the front side, and the first air blowing grill 11 is configured to slightly incline the wind blowing direction to the front side as shown in FIG. Wind direction guide plates 11a, 11a
.. Are provided. The second air blowing grille 12 has upper and lower opening tongues (guide portions) 12a and 12a so as to blow air obliquely upward and forward as shown in FIG.
b.

Further, a heat exchanger fitting port 1d is formed in the back surface of the blower chamber 5, and a flat heat exchanger 3 is fitted to the heat exchanger fitting port 1d. And
On the downstream side, the centrifugal fan 4 is inserted through a circular air inlet 14 formed in the center of a partition wall 15 for forming an air passage.
Are arranged. The centrifugal fan 4 is configured such that a rotating shaft 17 a fixed to the back surface of the front wall of the cassette casing 1 via a stay 9 is driven to rotate by a horizontal motor 17. In addition, around the centrifugal fan 4,
The first to third air portions are formed between the front wall 1b of the cassette casing 1 and the partition wall 15 around the air suction port 14 by the first tongue portion 21 and the second tongue portion 22 on the side wall 1c side. Air outlet passage 10 communicating with outlet grills 11 to 13
a, 10b, and 10c are formed.

The first tongue 21 and the second tongue 22 are separated from each other by, for example, the rotation angle θ of the
The opening angle θ ₁ (θ ₁ =
200 to 210 °), the lower second and third air outlet passages 10b and 10c have smaller opening angles θ ₂ (θ ₂ = 160).
To 150 °), and the wind from the centrifugal fan 4 in the rotation direction M draws streamlines as indicated by arrows, passes through the first to third outlet passages 10a to 10c, Third
From the outlet grills 11 to 13 at a predetermined air volume and wind speed.

In the above configuration, the air flow blown in the centrifugal direction by the centrifugal fan 4 is generated by the first and second tongues 21, 21.
The air is smoothly blown upward and laterally through the first, second, and third air blowout grills 11, 12, and 13 at the air flow rate set by 22. In particular, in this configuration, the widths of the first and second air blowing grilles 11 and 12 are wider and the passage area is wider than that of the first embodiment, so that the first and second air blowing grilles 11 and 12 are larger. 12, air can be blown out more efficiently from both upper and lower positions obliquely upward in the front side in a substantially parallel manner, and even in an installation state where there is not much room on the front side, stable air can be blown without inducing a short circuit. Can be realized.

In the above configuration, the third air blowing grill 13 can be omitted. In such a case, for example, the first and second air blowing grills 11
It is appropriate that the air flow ratio between 7 and 12 is 7: 3 to 8: 2.

Further, for the cassette casing 1 having the above configuration, a mixed flow fan 41 similar to that of the second embodiment is used.
It is needless to say that the same operation can be realized even if the above is applied.

(Embodiment 4) FIGS. 10 and 11
14 shows a configuration of an outdoor unit for an air conditioner according to Embodiment 4 of the present invention. This embodiment is characterized in that the same outdoor unit as that in each of the above embodiments is realized by combining two blowers.

In the drawing, reference numeral 10 denotes a flat box-shaped vertically long cassette casing of the outdoor unit 2. In the vertically elongated cassette casing 10, two spaces 31 and 32 are formed by a first partitioning wall 21 extending vertically at a substantially central portion.
The space 31 on the front side is further divided into two upper and lower two-stage air blow chambers 41 and 42 by a second partition wall 22 extending obliquely upward and forward and backward.

A first portion of a predetermined front and rear width extending in both right and left directions is provided at a front portion of a ceiling wall 10a of the cassette casing 10 forming a ceiling portion above the upper air blowing chamber 41.
Of the cassette casing 10 corresponding to the lower portion of the lower blower chamber 42
0b, a second portion having a predetermined vertical width extending in both left and right directions.
Of the air outlet grill 12 of the cassette casing 1
In the middle part of each of the upper and lower air blowing chambers 41, 42, a predetermined vertical width (lower side is larger) located above and below the second partition wall 22 and extending in both left and right directions. Third and fourth air blowing grilles 13 and 14 are provided, respectively.

The ceiling wall 10 of the cassette casing 10
a is inclined downward to the front side, and the first air blowing grille 11 has a wind direction guide plate 11a, 1 in which the wind blowing direction is slightly inclined forward as shown in FIG.
1a are provided. Further, the second air blowing grill 12 has upper and lower opening tongues (guide portions) 12a and 12b configured to blow air obliquely upward and forward as in the above-described embodiments. It is formed. Further, the third and fourth air blowing grills 1
3 and 14, the second partition wall 22 itself is inclined obliquely upward so as to blow air obliquely upward and forward, as shown in FIG. 11, to form a guide surface for blowing air obliquely upward. ing.

On the other hand, a heat exchanger fitting port 10d is formed in the opening of the space 32 behind the upper and lower ventilation chambers 41, 42, and a flat type extending in both upper and lower directions with respect to the heat exchanger fitting port 10d. Of the heat exchangers 3 are fitted. On the downstream side, the circular air inlets 1 formed corresponding to the upper and lower air blowing chambers 41 and 42 of the first partition wall 21, respectively.
Centrifugal fans 4, 4 are provided via 4, 14, respectively. The centrifugal fans 4, 4 have rotating shafts 17 a fixed to the back surface of the front wall 10 b of the cassette casing 10,
17a is rotatably driven by horizontal motors 17,17. Around the centrifugal fans 4, 4, between the front wall 10 b of the cassette casing 10 and the partition wall 21 around the air suction ports 14, 14, the first, third, fourth, and second Upper and lower air blowing passages 16a, 16b, 16c, 16d communicating with the respective air blowing grilles 11, 13, 14, 12 are formed.

In the above configuration, each air flow blown in the centrifugal direction by the pair of upper and lower centrifugal fans 4, 4 is divided into the first and third, fourth, and second upper and lower air blow grills 11, 13, The air is smoothly blown out via the nozzles 14 and 12, respectively. That is, from the first, second, third, and fourth air blowing grilles 11, 12, 13, and 14, air is blown from the upper and lower positions in a substantially obliquely upward and forward direction, respectively. Even in an installation state where there is not much room on the side, a stable air blowing mode can be realized without inducing a short circuit.

Particularly, in the case of the present embodiment, as shown in the figure, the strong upward flow of A ₂ having a large opening area and a large air flow deflects the flow of A ₁ ′ upward, and the front of the casing. There is also a Coanda effect along the wall 10b, and even if the installation space on the front side is small, it can be used without a short circuit. In particular, in the cooling operation in summer, even if the condensation temperature of the outdoor unit increases, the effect is amplified by the chimney effect.

In connection with the action, as described above, A ₂
In order to obtain a strong upward flow and reduce the flow rate in the downward flow path, which is difficult to flow, and aim the A ₂ ′ upward as much as possible, as in FIGS. It is also possible to adjust the sandwiching angle.

(Other Embodiments) The following sections in the above embodiments can be variously modified as follows, and the configurations thereof are arbitrarily adopted as needed.

(1) The heat exchanger 3 is not limited to the flat shape, but may be any of an L-shape, a U-shape and other shapes.

(2) Compressor 6 The compressor is not limited to the vertical type, but may be a horizontal type.

(3) Support structure for fan motors 17 and 47 In addition to the structure for supporting the front and rear surfaces of the casing front and rear through support stays, for example, it is positioned between the heat exchanger and the air suction port of the fan and A structure in which a stay is provided between the fins of the heat exchanger and supported in a vertical direction, which is supported via a stay installed in the vertical direction, may be used.

(4) Partition walls 8 and 81 separating the blower chamber 5 and the machine room 7 The partition walls may be replaced with, for example, an air suction space between a heat exchanger and an air suction port of a fan. May be provided only in the part that separates.

(5) Blowing direction from the second air outlet This can be changed to a horizontal direction. In particular, when the amount of air blown out of the second air outlet is smaller than the amount of air blown out of the first air outlet, such a case may be adopted.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of a casing of an outdoor unit for an air conditioner according to Embodiment 1 of the present invention.

FIG. 2 is a sectional view of the outdoor unit taken along the line AA in FIG. 1;

FIG. 3 is a sectional view of the outdoor unit taken along line BB in FIG. 1;

FIG. 4 is a perspective view showing a configuration of a casing of an outdoor unit for an air conditioner according to Embodiment 2 of the present invention.

5 is a sectional view of the outdoor unit taken along line AA of FIG. 4;

FIG. 6 is a sectional view of the outdoor unit taken along line BB of FIG. 4;

FIG. 7 is a perspective view showing a configuration of a casing of an outdoor unit for an air conditioner according to Embodiment 3 of the present invention.

8 is a sectional view of the outdoor unit taken along the line AA in FIG. 7;

FIG. 9 is a sectional view of the outdoor unit taken along line BB of FIG. 7;

FIG. 10 is a perspective view showing a configuration of a casing of an outdoor unit for an air conditioner according to Embodiment 4 of the present invention.

11 is a sectional view of the outdoor unit taken along the line AA in FIG. 10;

[Explanation of symbols]

1 is a cassette casing, 3 is a heat exchanger, 4 is a centrifugal fan, 11 is a first air outlet grill, 12 is a second air outlet grill, 13 is a third air outlet grill, and 14 is a fourth air outlet. The grill 41 is a mixed flow fan.

Claims (5)

[Claims] 1. An outdoor unit casing, a heat exchanger provided on the back side of the outdoor unit casing, a blower provided with a rotation axis directed substantially horizontally downstream of the heat exchanger, and the blower An air conditioner outdoor unit comprising: an air outlet for blowing air from the air conditioner; wherein the air outlet is a first air outlet for blowing air upward from a front part of a top plate of the outdoor unit casing; An outdoor unit for an air conditioner, comprising: a second air outlet for blowing air from a lower portion on the front side of the outdoor unit casing. 2. The air blower is located in the outdoor unit casing, and is provided in a plurality of upper and lower stages via a partition wall, and another air outlet is provided on the upper side of the partition wall and obliquely above the lower side of the upper side blower. 2. The outdoor unit for an air conditioner according to claim 1, wherein other air outlets are provided on the lower side of the partition wall and obliquely upward on the upper side of the lower side blower. 3. 3. An air blowing passage extending from a blower to each of the first and second air outlets to relatively adjust and set an amount of air blown from each of the first and second air outlets. The outdoor unit for an air conditioner according to claim 1, further comprising a tongue that is formed. 4. The outdoor unit for an air conditioner according to claim 1, wherein the blower comprises a centrifugal fan. 5. The outdoor unit for an air conditioner according to claim 1, wherein the blower comprises a mixed flow fan.