Technical Field
[0001] The present invention relates to an indoor unit of an air-conditioner and this is
especially suitable for an in-ceiling type indoor unit.
Background Art
[0002] The indoor unit of the air-conditioner is configured to perform indoor air conditioning
by drawing an indoor air flow through an air inlet, cooling the air flow by allowing
the same to pass through a heat exchanger, and blowing the cooled air flow into a
room through an air outlet. A wind direction adjusting louver (wind direction plate)
is installed on the air outlet of such air-conditioner such that an air outlet direction
of the air flow may be changed.
[0003] PTL 1 (
JP 2012-97958 A), for example, discloses this type of conventional art. PTL 1 discloses the air-conditioner
capable of preventing dew condensation by eliminating a temperature difference between
front and rear surfaces of the wind direction plate by allowing uniform temperature-regulated
air flow (cold air) to flow on both surfaces of the wind direction plate. That is
to say, PTL 1 discloses the air-conditioner provided with a jump ramp which allows
a flow of air to flow toward an opposite side of a wind-receiving surface of the wind
direction plate on a side wall of an air passage on a side opposed to the wind-receiving
surface of the wind direction plate, the jump ramp provided with a ventilation opening
which allows the flow of air to flow toward a side of the wind-receiving surface of
the wind direction plate.
Citation List
Patent Literature
Summary of Invention
Technical Problem
[0005] In the disclosure in PTL 1 described above, it is configured to send the temperature-regulated
air flow to a rear portion of the louver by providing the jump ramp and allow the
temperature-regulated air flow to flow on a design surface side (opposed side of the
wind-receiving surface) of the louver, thereby preventing the dew condensation.
[0006] Although the air outlet of the indoor unit is formed of a foamed polystyrene member
in general, since the jump ramp cannot be integrally formed with the foamed polystyrene
member forming the air outlet, it is necessary to manufacture the same as another
member and attach the same to the foamed polystyrene member with an adhesive and the
like, so that this increases a cost. Furthermore, if the jump ramp is provided on
the air outlet, a flow passage of the air outlet becomes narrower, so that an air
volume problematically decreases.
[0007] The wind direction adjusting louver installed on the air outlet of the indoor unit
of the air-conditioner is configured to change a direction of the outlet air flow
from a substantially vertical direction to a substantially horizontal direction. In
contrast, the air passage on an upstream side of the air outlet of the indoor unit
is a flow downward (vertical direction), and especially, when the outlet air flow
is set to be blown in the substantially horizontal direction by the louver, the temperature-regulated
air flow (cold air) is less likely to flow on the design surface side on a front side
(tip end side) of the louver. Therefore, it is understood that there is a problem
that a region (separated region) through which the cold air does not flow occurs on
the design surface side on the front side of the louver and the indoor air flow enters
the region and the dew condensation occurs. PTL 1 described above does not consider
about this problem.
[0008] An object of the present invention is to obtain the indoor unit of the air-conditioner
capable of inhibiting the occurrence of the dew condensation on the design surface
side of the louver even when the outlet air flow is blown in the substantially horizontal
direction.
Solution to Problem
[0009] In order to achieve the above-described object, the present invention is an indoor
unit of an air-conditioner, provided with:
a casing embedded in a ceiling; a decorative air panel provided on a bottom surface
of the casing; a blower and a heat exchanger provided within the casing; an air inlet
for drawing an indoor air flow into the casing; an air outlet for blowing an air flow
into a room; and a louver provided on the air outlet for adjusting a wind direction
of an outlet air flow, wherein
the louver having a cross-sectional shape formed of circular arcs with two or more
curvature radii is formed such that louver shape B/A is in a range of

if an angle between a tangent at a louver tip end of the circular arc forming a front
side portion of the louver and a level line is set to A and an angle between a tangent
at a louver rear end of the circular arc forming a rear side portion of the louver
and the level line is set to B in a fully-closed state of the louver.
Advantageous Effect of Invention
[0010] According to the present invention, there is an effect of obtaining the indoor unit
of the air-conditioner capable of inhibiting the occurrence of the dew condensation
on the design surface side of the louver even when the outlet air flow is blown in
the substantially horizontal direction.
Brief Description of Drawings
[0011]
FIG. 1 is a vertical cross-sectional view of a first embodiment of an indoor unit
of an air-conditioner of the present invention.
FIG. 2 is an enlarged cross-sectional view of a substantial part for illustrating
a shape of a louver and a flow of air around the same in the indoor unit of a conventional
air-conditioner.
FIG. 3 is an enlarged cross-sectional view of a substantial part of a state in which
the louver illustrated in FIG. 2 is fully closed.
FIG. 4 is an enlarged cross-sectional view of a substantial part for illustrating
the flow of air around the louver having an initially studied louver shape.
FIG. 5 is an enlarged cross-sectional view of a substantial part of a state in which
the louver illustrated in FIG. 4 is oriented in a substantially vertical direction
to realize vertical outlet.
FIG. 6 being an enlarged cross-sectional view of a substantial part of a configuration
in the vicinity of an air outlet in the first embodiment of the present invention
is a view for illustrating the flow of air around the louver.
FIG. 7 is an enlarged cross-sectional view of a substantial part of a state in which
the louver illustrated in FIG. 6 is oriented in the substantially vertical direction
to realize the vertical outlet.
FIG. 8 being an enlarged view of the louver illustrated in FIG. 6 is a view for illustrating
a shape of the louver.
FIG. 9B is a diagram for illustrating an air volume on a design surface side of a
louver tip end in a horizontal outlet state (FIG. 9A) in the first embodiment of the
present invention.
FIG. 10B is a diagram illustrating a total air volume blown through the air outlet
in a downward outlet state (FIG. 10A) in the first embodiment of the present invention.
Description of Embodiments
[0012] A specific embodiment of the present invention is hereinafter described with reference
to the drawings. Meanwhile, in each drawing, a part to which the same reference sign
is assigned indicates an identical or equivalent part.
First Embodiment
[0013] FIG. 1 being a vertical cross-sectional view of an indoor unit of an air-conditioner
of the first embodiment illustrates an example in which the present invention is applied
to an in-ceiling type indoor unit.
[0014] An indoor unit 1 includes a main body 1a embedded in a ceiling 11 and a decorative
air panel 1b covering an opening on a lower surface of the main body 1a. The decorative
air panel 1b is provided with an air inlet 2 through which an indoor air flow is drawn
and an air outlet 4 through which an air flow (conditioned air flow) conditioned by
a heat exchanger 3 installed within the main body 1a is blown into a room. A louver
7 which makes an air outlet direction of the air flow changeable is pivotally supported
by the air outlet 4 at end portions in a longitudinal direction thereof so as to be
rotatable.
[0015] A length of the louver 7 in the air outlet direction is made relatively long such
that the louver 7 in a closed state may substantially block the air outlet 4 (substantially
the same length as a width of the air outlet) for aesthetic purposes on a side of
a design surface of the decorative air panel 1b and for improved wind direction controllability
of an outlet air flow. The louver 7 in this embodiment is configured so as to be able
to change a wind direction of the outlet air flow from a substantially vertical direction
to a substantially horizontal direction.
[0016] An air passage 6 communicating with the air inlet 2 and the air outlet 4 is formed
within a casing 10 forming the main body 1a of the indoor unit 1, in the middle of
which an air blower 8 and the heat exchanger 3 are installed. It is configured such
that, when the air blower 8 is rotary-driven, the indoor air flow is drawn through
the air inlet 2, and the drawn air flow passes through the heat exchanger 3 and thereafter
sent toward the air outlet 4 to be blown into the room.
[0017] The heat exchanger 3 in which a cooling medium flowing therein forms a refrigeration
cycle is configured to operate as an evaporator at the time of cooling and operate
as a condenser at the time of heating, and to generate warm air or cold air by heat
exchange with the drawn air flow. The heat exchanger 3 is installed on a drain pan
5 and the drain pan 5 is configured to temporarily store drain water dropped from
the heat exchanger 3.
[0018] It is configured such that the air flow cooled, for example, by passage through the
heat exchanger 3 passes through the air passage 6 formed of the drain pan 5 and a
heat insulating material 9 provided on an inner surface of the casing 10 to be blown
through the air outlet 4 after the air outlet direction thereof is adjusted by the
louver 7.
[0019] Herein, a conventional structure of the louver 7 is first described with reference
to FIGS. 2 and 3. FIG. 2 is an enlarged cross-sectional view of a substantial part
for illustrating a shape of the louver and a flow of air around the same of the indoor
unit of a conventional air-conditioner, and FIG. 3 is an enlarged cross-sectional
view of a substantial part of a state in which the louver illustrated in FIG. 2 is
fully closed.
[0020] The conventional normal louver 7 has the shape as illustrated in FIGS. 2 and 3. That
is to say, as illustrated in FIG. 3, a curvature of the louver 7 on the design surface
side is often made similar to a curvature of a surface of the decorative air panel
1b in a portion of the air outlet 4 in consideration of design when the louver 7 is
closed. The flow of air in the vicinity of the air outlet 4 in the conventional indoor
unit 1 provided with the louver having such shape is described with reference to FIG.
2.
[0021] FIG. 2 illustrates the flow of air when the wind direction of the outlet air flow
is in the substantially horizontal direction (horizontal outlet state). In a case
of cooling operation, cold air (conditioned air flow) 12 passing through the air passage
6 is branched into a flow (branched flow) 12a on a side of a pressure surface of the
louver 7 and a flow (branched flow) 12b on an opposite side of the pressure surface
(design surface side) with a rear side (upstream side) end portion of the louver 7,
that is to say, a portion of a rear end 7a as a branching point. The branched flow
12b briefly flows in a direction opposite to the air outlet direction (direction to
the center of the indoor unit) by resistance of the rear end 7a of the louver 7. Therefore,
this cannot flow along the design surface side of the louver 7 and a region in which
the cold air does not flow along a louver surface, that is to say, a separated region
13 occurs. It is understood that, when the indoor air flow with high humidity enters
the separated region 13, this is brought into contact with the louver 7 cooled by
the cold air and dew condensation problematically occurs.
[0022] An initially studied plan for solving the problem is described with reference to
FIGS. 4 and 5. FIG. 4 is an enlarged cross-sectional view of a substantial part for
illustrating the flow of air around the louver having an initially studied louver
shape, and FIG. 5 is an enlarged cross-sectional view of a substantial part of a state
in which the louver illustrated in FIG. 4 is oriented in the substantially vertical
direction to realize vertical outlet.
[0023] In the louver shape illustrated in FIGS. 4 and 5, a curvature radius of the louver
is made small. FIG. 4 illustrates the flow of air when the wind direction of the outlet
air flow is in the substantially horizontal direction (horizontal outlet state) with
the rear end 7a of the louver 7 oriented upward. Although the cold air 12 passing
through the air passage 6 is branched into the branched flow 12a on the side of the
pressure surface of the louver 7 and the branched flow 12b on the opposite side of
the pressure surface with the portion of the rear end 7a of the louver 7 as the branching
point in this case also, the outlet air flow is smoothly branched at the rear end
7a of the louver 7 and the branched flow 12b does not flow in the direction opposite
to the air outlet direction but flows along the design surface side of the louver
7.
[0024] However, due to the small curvature radius, the Coanda effect by which the outlet
air flow (branched flow 12b) flows along the opposite side of the pressure surface
of the louver 7 does not sustain to a louver tip end, so that the outlet air flow
is separated in the vicinity of a tip end 7b of the louver 7 and the separated region
13 also occurs as represented by a reference sign 13 in FIG. 4. Although the separated
region 13 is smaller than the separated region in a case of the conventional louver
shape illustrated in FIG. 2, as in the case in FIG. 2, the indoor air flow with high
humidity enters the separated region 13 to be brought into contact with the cooled
louver 7 and the dew condensation occurs.
[0025] Also, as illustrated in FIG. 5, in a state in which the louver 7 is oriented in the
substantially vertical direction to blow downward (downward outlet state), due to
the small curvature radius of the louver 7, the outlet air flow is less likely to
flow along the side of the pressure surface (inner side) of the louver 7, and a region
14 in which the air flow flows with difficulty in FIG. 5 occurs. This has the same
meaning as a narrow air passage 6 or air outlet 4 and this causes decrease in air
volume due to increase in ventilation resistance.
[0026] Furthermore, in this example, due to the small curvature radius of the louver 7,
there also is a problem that the tip end 7b of the louver 7 is also oriented upward
at the time of the horizontal outlet state as illustrated in FIG. 4, smudging in which
an outlet air flow 12c blown through the air outlet 4 flows in a direction toward
the ceiling 11 occurs, and a ceiling surface gets dirty.
[0027] Next, the louver shape in the indoor unit of this embodiment illustrated in FIG.
1 is described with reference to FIGS. 6 to 8. FIG. 6 being an enlarged cross-sectional
view of a substantial part of a configuration in the vicinity of the air outlet in
the first embodiment of the present invention is a view for illustrating the flow
of air around the louver, FIG. 7 is an enlarged cross-sectional view of a substantial
part of a state in which the louver illustrated in FIG. 6 is oriented in the substantially
vertical direction to realize the vertical outlet, and FIG. 8 being an enlarged view
of the louver illustrated in FIG. 6 is a view for illustrating the louver shape.
[0028] FIG. 6 illustrates the flow of air when the wind direction of the outlet air flow
is in the substantially horizontal direction (horizontal outlet state) with the rear
end 7a of the louver 7 oriented upward. In this embodiment also, the cold air 12 passing
through the air passage 6 is branched into the branched flow 12a on the side of the
pressure surface of the louver 7 and the branched flow 12b on the opposite side of
the pressure surface with the portion of the rear end 7a of the louver 7 as the branching
point, but the outlet air flow is smoothly branched at the rear end 7a of the louver
7 and the branched flow 12b does not flow in the direction opposite to the air outlet
direction but flows along the design surface side of the louver 7.
[0029] That is to say, in the louver 7 of this embodiment, the rear end 7a of the louver
7 is oriented upward in order to realize smooth branching of the outlet air flow at
the louver rear end 7a in the horizontal outlet state. In order to prevent separation
of the outlet air flow (cold air) on the design surface side (opposite side of the
pressure surface) on a side of the louver tip end 7b and prevent the occurrence of
the smudging in which the outlet air flow flows in the direction toward the ceiling
11 and the ceiling surface gets dirty, a shape of a front side portion of the louver
7 is made different from a shape of a rear side portion to obtain a forward-backward
asymmetric shape. According to this, the separation of the cold air on the design
surface side of the louver 7 is prevented, and the occurrence of the dew condensation
is inhibited.
[0030] FIG. 7 illustrates the flow of air in a state in which the louver 7 is oriented
in the substantially vertical direction and the wind direction of the outlet air flow
is in the substantially vertical direction (downward outlet state) in the indoor unit
of this embodiment. As illustrated in FIG. 7, in this embodiment, the wind easily
flows along the side of the pressure surface (inner side) of the louver 7 also in
the downward outlet state, so that the region 14 in which the air flow flows with
difficulty as illustrated in FIG. 5 does not occur or this is extremely small as represented
by a reference sign 14 in FIG. 7 even if this occurs. Therefore, the ventilation resistance
in the air passage 6 and the air outlet 4 may be made small, so that it is also possible
to prevent decrease in total air volume blown through the air outlet 4.
[0031] A detailed shape of the louver 7 in this embodiment is described with reference to
FIG. 8. A cross-sectional shape of the louver 7 of this embodiment is formed of circular
arcs 30 and 31 with two curvature radii R1 and R2, respectively. Meanwhile, it is
also possible to form the louver 7 of circular arcs with three or more curvature radii.
In this embodiment, the louver 7 is formed such that the curvature radius R2 forming
the rear side portion of the louver 7 is smaller than the curvature radius R1 forming
the front side portion of the louver 7.
[0032] An angle between a tangent 32 at the louver tip end 7a of the circular arc 30 with
the curvature radius R1 forming the front side portion of the louver 7 and a level
line (a line indicating level line 34) in a fully-closed state as illustrated in FIG.
8 is set to an angle A. An angle between a tangent 33 at the louver rear end 7b of
the circular arc 31 with the curvature radius R2 forming the rear side portion of
the louver 7 and the level line (the line indicating level line 34) is set to an angle
B.
[0033] In the conventional normal louver shape, "B/A = 1" is satisfied in general. In contrast,
the louver shape of this embodiment illustrated in FIG. 8 is configured to satisfy
"B/A ≈ 3". Meanwhile, the shape of the louver in this embodiment may be in a range
of "B/A = 2 to 4". A reason for this is hereinafter described with reference to FIGS.
9 and 10.
[0034] FIG. 9A is a view of the louver having the shape illustrated in FIG. 8 in the horizontal
outlet state, and FIG. 9B illustrates the air volume in a part 15 on the design surface
side of the louver tip end with respect to the louver shape B/A in the state illustrated
in FIG. 9A. It is indicated that, the larger the air volume in the part 15 is, the
more the outlet air flow flows along the louver, so that the dew condensation is less
likely to occur, that is to say, dew condensation proof is higher. The air volume
in the part 15 tends to be larger when B/A of the louver shape is larger, and the
air volume is the largest when "B/A = 4" is satisfied. It is also understood that
the air volume significantly decreases with the conventional louver shape (B/A = 1)
and the dew condensation easily occurs. From FIG. 9B, it is understood that the occurrence
of the dew condensation may be inhibited when B/A is set to 2 or larger and especially,
the occurrence of the dew condensation may be significantly inhibited when this is
set to 3 or larger.
[0035] FIG. 10A is a view of the louver having the shape illustrated in FIG. 8 in the downward
outlet state, and FIG. 10B illustrates the total air volume blown through the air
outlet 4 with respect to the louver shape B/A in the state illustrated in FIG. 10A.
It is indicated that, the larger the total air volume is, the smaller the ventilation
resistance at the air outlet 4 is, so that pressure loss is smaller. The total air
volume tends to be smaller as B/A of the louver shape is larger. That is to say, it
is understood that, in the downward outlet state of the louver, the louver 7 does
not block the air passage 6 and the air outlet 4 when the louver shape B/A is smaller,
so that the total air volume increases. From FIG. 10B, B/A is preferably set to 4
or smaller.
[0036] From a result of FIGS. 9 and 10 described above, it is understood that the occurrence
of the dew condensation may be inhibited even in the horizontal outlet state of the
louver and decrease in total air volume may be inhibited even in the downward outlet
state of the louver when
[0037] B/A = 2 to 4 of the louver shape B/A is satisfied. Therefore, the louver shape B/A
may be set to 2 to 4 and preferably set to approximately 3 (2.5 to 3.2).
[0038] As described above, according to this embodiment, since the angle of the louver rear
portion relative to the level line is made larger than that of the front portion,
specifically, the louver shape B/A is set to 2 to 4, it is possible to allow the cold
air (conditioned air flow) to flow along the design surface side of the louver even
in the horizontal outlet state in which the outlet air flow is blown in the substantially
horizontal direction, so that the indoor unit of the air-conditioner capable of inhibiting
the occurrence of the dew condensation on the design surface side of the louver may
be obtained. In addition, according to this embodiment, the dew condensation may be
prevented without providing a member such as a jump ramp disclosed in PTL 1, and further,
it is possible to prevent the ceiling surface from getting dirty by the smudging.
According to this embodiment, an effect of minimizing the decrease in total air volume
even in the downward outlet state of the outlet air flow may also be obtained.
[0039] Meanwhile, the present invention is not limited to the above-described embodiment
and various modifications may be included. For example, although a case in which the
present invention is applied to a one-way outlet type indoor unit which draws the
indoor air flow from a lower surface on a rear side of the indoor unit 1 and blows
the conditioned air flow from the lower surface on a front side of the indoor unit
1 is described in this embodiment, this may also be similarly applied to a four-way
outlet type indoor unit which draws the indoor air flow from the lower surface on
the center of the indoor unit and blows the conditioned air flow from four portions
on the lower surface on an outer peripheral side of the indoor unit.
[0040] Furthermore, the above-described embodiment is described in detail in order to describe
the present invention in an easily-understood manner, and the present invention is
not necessarily limited to the embodiment provided with all the described configurations.
Reference Signs List
[0041] 1 indoor unit, 1a main body, 1b decorative air panel, 2 air inlet, 3 heat exchanger,
4 air outlet, 5 drain pan, 6 air passage, 7 louver, 7a tip end, 7b rear end, 8 blower,
9 heat insulating material, 10 casing, 11 ceiling, 12 cold air (conditioned air flow),
12a, 12b branched flow, 12c outlet air flow, 13 separated region, 14 region in which
air flow flows with difficulty, 15 part on design surface side of louver tip end,
30, 31 circular arc, 32, 33 tangent, 34 line indicating level line.