TECHNICAL FIELD
[0001] The present invention relates to an indoor unit for an air conditioner. Such an indoor
unit may be installed on an indoor floor or at a low place in the vicinity thereof
so that conditioned air is blown upward and sideways.
BACKGROUND ART
[0002] In general, an air conditioner performs indoor cooling or heating by blowing cooled
air or warmed air indoors and circulating it indoors through convection.
[0003] However, when performing indoor cooling or heating by such a forced convection system,
an influence heat radiation from a perimeter zone to a central residence area becomes
a problem. That is, for example, in summer or winter, the difference between the outdoor
temperature and the indoor temperature is large, and heat enters the indoor side from
the outdoor side. As a result, a cooling load or a heating load when air-conditioning
increases, thus impairing comfortableness in cooling/heating.
[0004] As a technique to suppress deterioration of the comfortableness in cooling or heating
due to the influence of heat from the perimeter zone, there is proposed a method of
performing cooling/heating wherein an indoor unit for an air conditioner is installed
on an indoor floor by an indoor wall or a window or at a low place in the vicinity
of the floor, and conditioned air is blown upward and sideways to form an air barrier
in the vicinity of the perimeter zone, thereby performing indoor cooling or heating
while eliminating the influence of heat from the perimeter zone.
[0005] Fig. 26 shows an indoor unit Z
0 used for such a purpose, and Fig. 27 shows a refrigerant circuit of an air conditioner
equipped with the indoor unit Z
0. In Fig. 27, arrow W in the broken line indicates the direction of the flow of a
refrigerant when heating, while arrow C in the solid line indicates the direction
of the flow of the refrigerant when cooling. The indoor unit Z
0 is constructed as follows: in a rectangular-shaped casing 1 having an air inlet 2
in the front surface 1a, an upper surface air outlet 3 in the upper surface 1b and
side surface air outlets 4 in the side surfaces 1c, 1c, centrifugal fans 5, 5 are
disposed with their suction sides directed to the air inlet 2, and a heat exchanger
6 is positioned between the suction side of the fans 5 and the inlet 2. Indoor air
sucked by the fans 5 through the air inlet 2 is heat exchanged by the heat exchanger
6 to give cooled or warmed air. The resultant cooled or warmed air is blown upward
from the upper surface air outlet 3 or blown sideways from the side surface air outlets
4, 4 respectively. As shown in Fig. 27, this indoor unit Z
0 is connected to an outdoor unit Y equipped with a compressor 9, a direction switching
valve 10, an outdoor-side heat exchanger 11 and a main expansion valve 12, via refrigerant
piping (collectively referred to as P), thus constituting an air conditioner.
[0006] However, such a low-place installation type conventional indoor unit Z
0 has a structure in which the heat exchanger 6 is positioned on the suction side of
the fans 5, and the upper surface air outlet 3 and the side surface air outlets 4,
4 directly face the discharge side of the fans 5. Therefore, in both of the heating
operation shown in Fig. 28 and the cooling operation shown in Fig. 29, sucked air
Aa is heat exchanged by the heat exchanger 6 and then blown through the upper surface
air outlet 3 as upper outlet air Ab and blown through the upper side surface air outlets
4 as side outlet air Ac. The upper outlet air and the side outlet air have the same
temperature.
[0007] Accordingly, the upper outlet air Ab from the upper surface air outlet 3 and the
side outlet air Ac from the side surface air outlets 4 form an air barrier by the
window or by the wall thereby achieving a function of controlling entry of heat radiation.
However, the temperature on the floor side is lowered in the heating operation due
to rising of warm air from the indoor floor, while cold air is liable to remain on
the floor side in the cooling operation. In both of these operations, realization
of a "cooling a head and warming feet" ambience, which is an ambience of an ideal
temperature distribution, is difficult, and there was a problem of impairing a comfortable
air conditioning.
[0008] Published Japanese Patent Application
JP 10 141741 A discloses a combination of features falling within the scope of the preamble of claim
1.
SUMMARY OF THE INVENTION
[0009] According to the present invention, there is provided an indoor unit for an air conditioner
comprising a casing having an air inlet in a front surface, an upper surface air outlet
in an upper surface and a side surface air outlet in a side surface and installable
on an indoor floor or in the vicinity of the indoor floor, and a fan and a first heat
exchanger that are disposed in the casing such that the first heat exchanger lies
on a suction side of the fan, wherein said indoor unit further comprises a means for
regulating a temperature of either upper outlet air from the upper surface air outlet
or side outlet air from the side surface air outlet such that the temperature of the
upper outlet air is lower than the temperature of the side outlet air, characterised
in that: the means for regulating a temperature of either upper outlet air from the
upper surface air outlet or side outlet air from the side surface air outlet comprises
a second heat exchanger within the casing; and the first heat exchanger is positioned
upstream in a direction of airflow, while the second heat exchanger is positioned
downstream in the direction of airflow, and the second heat exchanger faces any one
of the upper surface air outlet and the side surface air outlet.
[0010] With this construction, in the cooling operation, colder air is blown to an upper
part of a room, while relatively warm air is blown to a lower part of the room. Therefore,
the "cooling a head and warming feet" ambience is realized, and a sensation of being
comfortably cooled (comfortable cooling sensation) can be obtained by efficiently
restraining cold air from gathering at one's feet. On the other hand, in the heating
operation, rising of warm air from the vicinity of the floor is controlled by the
low-temperature air in the upper part of the room, whereby the "cooling a head and
warming feet" ambience is realized, and a sensation of being comfortably heated (comfortable
heating sensation) is obtained.
[0011] In the case where the second heat exchanger is provided on the side of the upper
surface air outlet, in the cooling operation, the air to be blown upward through the
upper surface air outlet passes both the first heat exchanger and the second heat
exchanger to be cooled by both of them. Therefore, the temperature of the air becomes
lower than that of air to be blown sideways through the side surface air outlet, the
latter passing only the first heat exchanger. The cooler air is blown to the upper
part of the room, while the relatively warm air is blown to the lower part of the
room. Therefore, the "cooling a head and warming feet" state is realized, and a comfortable
cooled sensation is obtained by efficiently suppressing cold air gathered at one's
feet. That is, an operation that lays stress on the comfortableness in cooling is
realized.
[0012] On the other hand, in the case where the second heat exchanger is provided for the
side surface air outlet, in the heating operation, air to be blown sideways from the
side surface air outlet passes both the first heat exchanger and the second heat exchanger.
Therefore, the temperature of the air blown sideways becomes higher than that of air
blown upward from the upper surface air outlet, which passes only the first heat exchanger,
and warm air in the vicinity of the floor is restrained from rising by cold air in
the upper part of the room. Therefore, the "cooling a head and warming feet" ambience
is realized, and a comfortable heating sensation is obtained. That is, an operation
that lays stress on the comfortableness in warming is realized.
[0013] An advantage achievable with embodiments of the present invention is to realize a
"cooling a head and warming feet" ambience of ideal temperature distribution without
a sense of draft and improving comfortableness of air conditioning in a low-place
installation type conventional indoor unit.
[0014] The second heat exchanger may be formed integrally with or separately from the first
heat exchanger. In the case where they are formed integrally, it is possible to reduce
the production costs by reduction in the number of components or in the number of
assembling process steps to thereby provide an indoor unit inexpensively. On the other
hand, when the first and second heat exchangers are formed separately, or as separate
pieces, the freedom of layout of the first and second heat exchangers relative to
the casing is improved, so that it is possible to easily address diversification of
needs regarding the indoor unit configuration.
[0015] In one embodiment, the second heat exchanger is disposed facing the upper surface
air outlet, and the second heat exchanger is made to function as an evaporator on
a low-pressure side in a cooling operation, and, in a heating operation, as an evaporator
on a side a little closer to a high-pressure side than in the cooling operation.
[0016] In this embodiment, in the heating operation, a relatively low-temperature air, which
was first heated by the first heat exchanger and then cooled by the second heat exchanger
functioning as the evaporator on the side closer to the low-pressure side than the
first heat exchanger, is blown out from the upper surface air outlet. On the other
hand, a relatively high-temperature air only heated by the first heat exchanger is
blown out from the side surface air outlet. Thus, rising of the air having a relatively
high temperature in the lower part of the room is suppressed by the air having a relatively
low temperature in the upper part of the room. Therefore, "cooling a head and warming
feet" is realized, and a comfortable warming sensation is obtained.
[0017] On the other hand, in the cooling operation, a low-temperature air, which passed
both the first heat exchanger and the second heat exchanger and was cooled by both
of them, is blown through the upper surface air outlet. In contrast, a relatively
high-temperature air, which passed only the first heat exchanger, is blown through
the side surface air outlet. Therefore, a "cooling a head and warming feet" ambience
is realized, and a comfortable cooling sensation is obtained by efficiently restraining
cold air from gathering at one's feet.
[0018] In another embodiment, the second heat exchanger is disposed facing the side surface
air outlet, and the second heat exchanger is made to function as a condenser on a
high-pressure side in a heating operation, and, in a cooling operation, as an evaporator
on a side a little closer to a low-pressure side than in the heating operation.
[0019] In this embodiment, in the heating operation, a high-temperature air heated by the
first heat exchanger and further heated by the second heat exchanger is blown from
the side surface air outlet. In contrast, a relatively low-temperature air heated
by only the first heat exchanger is blown from the upper surface air outlet. Thus,
rising of the relatively high-temperature air from the lower part of the room is controlled
by the relatively low-temperature air in the upper part of the room. Therefore, "cooling
a head and warming feet" is realized, and a comfortable heating sensation is obtained.
[0020] On the other hand, in the cooling operation, a relatively high-temperature air first
cooled by the first heat exchanger and then heated by the second heat exchanger functioning
as the evaporator on the side closer to the high-pressure side than the first heat
exchanger is blown out from the side surface air outlet. In contrast, a low-temperature
air that passed only the first heat exchanger is blown from the upper surface air
outlet. Therefore, "cooling a head and warming feet" is realized, and a comfortable
cooling sensation is obtained by efficiently suppressing cold air gathering at one's
feet.
[0021] The heat exchanger and/or the second heat exchanger may be constructed of a stack
type heat exchanger comprising a plurality of flat heat exchanger tubes and a plurality
of fins being alternately stacked, with both end portions of each of the flat heat
exchanger tubes being connected by headers, respectively. The characteristics of the
stack-type heat exchanger make it possible to reduce the thickness of the heat exchanger,
as compared with the case where each of the first heat exchanger and the second heat
exchanger is constructed of a cross-fin type heat exchanger, for example. As a result,
it becomes possible to achieve both downsizing and improvement in the performance
of the indoor unit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] To enable a better understanding of the present invention, and to show how the same
may be carried into effect, reference will now be made, by way of example only, to
the accompanying drawings, in which:-
Fig. 1 is a perspective view showing an installation state of one embodiment of an
indoor unit for an air conditioner of the type used in accordance with the present
invention;
Fig. 2 is a cross-sectional view showing an arrangement of heat exchangers in a first
embodiment of an indoor unit for an air conditioner according to the present invention;
Fig. 3 is a refrigerant circuit diagram of an air conditioner including the indoor
unit shown in Fig. 2;
Fig. 4 is an operation diagram of an air conditioner including the indoor unit shown
in Fig. 2 in a heating operation;
Fig. 5 is an operation diagram of an air conditioner including the indoor unit shown
in Fig. 2 in a cooling operation;
Fig. 6 is a plan view showing the structure of a stack-type heat exchanger;
Fig. 7 is a refrigerant circuit-diagram of an air conditioner including a second embodiment
of an indoor unit according to the present invention;
Fig. 8 is an operation diagram of the air conditioner shown in Fig. 7 in a heating
operation;
Fig. 9 is an operation diagram of the air conditioner shown in Fig. 7 in a cooling
operation;
Fig. 10 is a sectional view showing an arrangement of heat exchangers in a third embodiment
of an indoor unit for an air conditioner according to the present invention;
Fig. 11 is a refrigerant circuit diagram of the air conditioner shown in Fig. 10;
Fig. 12 is an operation diagram of the air conditioner shown in Fig. 10 in a heating
operation;
Fig. 13 is an operation diagram of the air conditioner shown in Fig. 10 in a cooling
operation;
Fig. 14 is a refrigerant circuit diagram of an air conditioner including a fourth
embodiment of an indoor unit according to the present invention;
Fig. 15 is an operation diagram of the air conditioner shown in Fig. 14 in a heating
operation;
Fig. 16 is an operation diagram of the air conditioner shown in Fig. 14 in a cooling
operation;
Fig. 17 is a refrigerant circuit diagram of an air conditioner including a fifth embodiment
of an indoor unit according to the present invention;
Fig. 18 is an operation diagram of the air conditioner shown in Fig. 17 in a heating
operation;
Fig. 19 is an operation diagram of the air conditioner shown in Fig. 17 in a cooling
operation;
Fig. 20 is a refrigerant circuit diagram of an air conditioner including a sixth embodiment
of an indoor unit according to the present invention;
Fig. 21 is an operation diagram of the air conditioner shown in Fig. 20 in a heating
operation;
Fig. 22 is an operation diagram of the air conditioner shown in Fig. 20 in a cooling
operation;
Fig. 23 is a refrigerant circuit diagram of an air conditioner of a first example
useful for understanding the present invention;
Fig. 24 is a sectional view of an indoor unit in an air conditioner of a second example
useful for understanding the present invention;
Fig. 25 is a sectional view of an indoor unit in an air conditioner of a third example
useful for understanding the present invention;
Fig. 26 is a sectional view showing an arrangement of heat exchangers of an indoor
unit in a conventional air conditioner;
Fig. 27 is a refrigerant circuit diagram of the conventional air conditioner;
Fig. 28 is an operation diagram of the conventional air conditioner in a heating operation;
and
Fig. 29 is an operation diagram of the conventional air conditioner in a cooling operation.
DETAILED DESCRIPTION
[0023] The present invention will be specifically described below, based on several exemplary
illustrated embodiments.
[0024] First, Fig. 1 shows an indoor unit Z of a separate type air conditioner, for which
type of air conditioner the indoor unit of the present invention is intended. As shown
in Fig. 1, this indoor unit Z is a floor installation type indoor unit, which is preferably
installed in a perimeter zone having a particularly high air conditioning load in
the interior of a room, such as in a region in the vicinity of a window part 53, so
as to contrive a reduction in the air conditioning load. The indoor unit is installed
on an indoor floor 51 against a room wall 52 below of the window part 53, and performs
indoor air conditioning by blowing conditioned airflow upward and sideways at the
same time, while suppressing entry of radiant heat from the window part 53 and so
on.
[0025] The indoor unit Z has a rectangular casing 1 that is advantageous to installation
against a wall surface. The front surface 1a, the upper surface 1b, and the left and
right side surfaces 1c, 1c of the casing 1 are provided with an air inlet 2, an upper
surface air outlet 3, and side surface air outlets 4, 4, respectively.
[0026] Within the casing 1, right and left centrifugal fans 5, 5 are laterally juxtaposed
at a predetermined interval with their suction sides opposed to the air inlet 2. A
first heat exchanger 6 is positioned between the suction side of the fans 5, 5 and
the air inlet 2. The constitution in which the first heat exchanger 6 is positioned
on the suction sides of the fans 5, as described above, is a basic constitution of
the indoor unit Z. In addition to the above basic constitution, the indoor unit of
the present invention further comprises a means for regulating the temperature of
either of the upper outlet air Ab from the upper surface air outlet 3 or the side
outlet air Ac from the side surface air outlets 4 so that the temperature of the upper
outlet air Ab from the upper outlet 3 is lower than the temperature of the side outlet
air Ac from the side surface air outlets 4. More specifically, provision of a second
heat exchanger 7 for the upper surface air outlet 3 or of the second heat exchangers
8 for the side surface air outlets 4 is made, preferably selectively in accordance
with required conditions such as indoor air conditioning characteristics so that the
comfortableness in cooling and heating can be enhanced.
[0027] When the upper surface air outlet 3 is provided with the second heat exchanger 7,
sucked air Aa sucked through the air inlet 2 passes the first heat exchanger 6. Then,
a part of the sucked air further passes the second heat exchanger 7 and is blown upward
as the upper outlet air, while another part is blown sideways as it is from the side
surface air outlets 4 as the side outlet air Ac.
[0028] When the side surface air outlets 4 are provided with the second heat exchangers
8, the sucked air Aa passes the first heat exchanger 6 and then one part of the sucked
air further passes the second heat exchangers 8 and is blown sideways from the side
surface air outlets 4 as the side outlet air, while another part is blown upward from
the upper surface air outlet 3 as the upper outlet air Ab.
[0029] Preferred embodiments, and examples useful for understanding the invention, of indoor
units for air conditioners will be specifically described below based on the accompanying
drawings.
First Embodiment (see Figs. 2-5)
[0030] As shown in Fig. 2, an indoor unit Z1 of a first embodiment is structured such that
the first heat exchanger 6 is disposed in correspondence with the air inlet 2 of the
casing 1, and that, of the upper surface air outlet 3 and the right and left side
surface air outlets 4, the second heat exchangers 8 are provided for the respective
side surface air outlets 4, 4. Therefore, with the operation of the fans 5, 5, the
sucked air Aa sucked from the air inlet 2 pass the first heat exchanger 6 and then,
one part of the sucked air is blown as it is from the upper surface air outlet 3 as
the upper outlet air Ab, while another part of the sucked air further passes the second
heat exchanger 8 and is blown from the side surface air outlet 4 as the side outlet
air Ac.
[0031] The constitution of a refrigerant circuit of the whole air conditioner including
the indoor unit Z
1 is shown in Fig. 3. This air conditioner is composed of the indoor unit Z
1 and an outdoor unit Y connected to each other via refrigerant piping P. The outdoor
unit Y is provided with a compressor 9, a direction switching valve 10, an outdoor
heat exchanger 11 and an expansion valve 12, while the indoor unit Z
1 is provided with the first heat exchanger 6 and the second heat exchangers 8. In
the indoor unit of this embodiment, the arrangement of the first heat exchanger 6
and the second heat exchangers 8 is set so that the second heat exchangers 8 are positioned
on the upstream side of the first heat exchanger 6 in the circulation direction of
the refrigerant in the cycle of cooling operation.
[0032] Next, functions of the indoor unit Z
1 of this embodiment in the heating and cooling operations will be described.
[0033] In the indoor unit Z
1 of this embodiment, the second heat exchangers 8 are disposed on the side of the
side surface air outlets 4, and no heat exchanger is provided on the side of the upper
surface air outlet 3. Therefore, in both heating and cooling operations, the side
outlet air Ac to be blown from the side surface air outlet 4 is subjected to heat
exchange by the first heat exchanger 6 and the second heat exchanger 8, while the
upper outlet air Ab to be blown from the upper surface air outlet 3 is subjected to
heat exchange by only the first heat exchanger 6. As a result, a temperature difference
arises between the side outlet air Ac and the upper outlet air Ab. This indoor unit
Z
1 is intended to improve the comfortableness particularly in heating operations, using
this temperature difference between the side outlet air Ac and the upper outlet air
Ab efficiently.
[0034] That is, as shown in Fig. 4, in the heating operation of the indoor unit Z
1, of the sucked air Aa, the upper outlet air Ab to be blown from the upper surface
air outlet 3 is subjected to heating by only the first heat exchanger 6, and the side
outlet air Ac to be blown from the side surface air outlets 4 is subjected to heating
by both of the first heat exchanger 6 and the second heat exchanger 8. Therefore,
the upper outlet air Ab has a relatively low temperature, while the side outlet air
Ac has a relatively high temperature. As a result, the air having a relatively high
temperature is present in the vicinity of the floor 51, or a lower part of the room,
and the air having a relatively low temperature is present in an upper part of the
room. Thus, rising of the air having a high temperature in the vicinity of the floor
is controlled by the air having a low temperature in the upper part of the room, and
"cooling a head and warming feet" that is the ideal temperature distribution is realized.
That is, the operation that considers the comfortableness in heating is realized.
[0035] On the other hand, in the cooling operation of the indoor unit Z
1, as shown in Fig. 5, a low-temperature air subjected to cooling by the first heat
exchanger 6 and the second heat exchanger 8 is blown from the side surface air outlets
4 as the side outlet air Ac. On the other hand, a relatively high-temperature air
cooled by only the first heat exchanger 6 is blown from the upper surface air outlet
3 as the upper outlet air Ab. For that reason, if the comfortableness is desired also
in the cooling operation, for example, the side surface air outlets 4 may be closed,
or the side surface air outlet 4 may be opposed to a wall with little interval therebetween
so that the discharge of the side outlet air Ac from the side surface air outlet 4
is suppressed.
[0036] As the first heat exchanger 6 and the second heat exchangers 7, 8, a "cross-fin type
heat exchanger" is generally adopted. From the viewpoint of downsizing the indoor
unit Z
1, it is preferred that the first heat exchanger 6 and/or the second heat exchanger
7, 8 is composed of a stack-type heat exchanger 30 comprising a plurality of flat
heat exchanger tubes 31, 31, ···, and a plurality of corrugated fins 32, 32, ···,
which are alternately stacked, both end portions of each of the flat heat exchanger
tubes 31 being connected by headers 33, 34 respectively.
[0037] Furthermore, generally, in an indoor unit wherein paired fans 5, 5 are disposed at
a predetermined lateral distance within a casing 1 as in the present embodiment, such
fans 5, 5 are arranged to rotate in the same direction. However, when the paired fans
5, 5 are rotated in the same direction as described above, obliquely downward velocity
components of the side outlet air Ac blown from the side surface air outlets 4 increase,
and a sense of downdraft increases particularly in the cooling operation. Therefore,
such an arrangement is not preferred in view of comfortableness.
[0038] In order to control such a downdraft efficiently, it is useful to set the rotational
directions of the fans 5, 5 such that both of these fans 5, 5 are rotated in opposite
outward directions as seen from their suction side. Contrary to this, when the paired
fans 5, 5 are arranged such that they are rotated inwardly as seen from their suction
sides, the downdraft controlling effect is reduced, but the distance between the two
fans 5, 5 can be reduced. Therefore, the latter arrangement is advantageous in view
of a reduction in the size of the indoor unit.
[0039] It is also possible to constitute the indoor unit so that the numbers of revolutions
of the fans 5, 5 are independently controlled. When this constitution is adopted,
zoning according to the demand for air conditioning becomes available; e.g., the number
of revolutions of the fan 5 positioned on the side closer to a region where someone
is present may be set higher, while the number of revolutions of the fan 5 positioned
on the side closer to a region where no one is present may be set lower, and so on.
Thus, a further improvement in the comfortableness can be expected.
Second Embodiment (see Figs. 7-9)
[0040] Fig. 7 shows a refrigerant circuit of the whole air conditioner provided with an
indoor unit Z
2 of a second embodiment of the present invention. In the indoor unit Z
1 of the first embodiment, the refrigerant path is set so that the first heat exchanger
6 is positioned downstream of the heat exchangers 8 in the cooling cycle. Contrary
to this, in the indoor unit Z
2 of the second embodiment, a refrigerant path is set so that the first heat exchanger
6 is positioned upstream of the second heat exchangers 8 in the cooling cycle.
[0041] Therefore, as shown in Figs. 8 and 9, in the same manner as in the indoor unit Z
1 of the first embodiment, in both of the heating operation and the cooling operation,
the side outlet air Ac from the side surface air outlet 4 is heated or cooled by the
first heat exchanger 6 and the second heat exchanger 8, and the upper outlet air Ab
from the upper surface air outlet 3 is heated or cooled by only the first heat exchanger
6. Thus, a temperature difference arises between the side outlet air Ac and the upper
outlet air Ab. As a result, in the same manner as in the indoor unit Z
1 of the first embodiment, the operation that lays stress on the comfortableness in
heating operation is realized.
Third Embodiment (see Fig. 10-13)
[0042] As shown in Fig. 10, an indoor unit Z
3 of a third embodiment is structured such that the first heat exchanger 6 is disposed
in correspondence with the air inlet 2 of the casing 1, and that, of the upper surface
air outlet 3 and the right and left side surface air outlets 4, the second heat exchanger
7 being provided for the upper surface air outlet 3. Therefore, with the operation
of the fans 5, 5, the sucked air Aa sucked through the air inlet 2 passes the first
heat exchanger 6 and then a part of the sucked air is blown as it is from the side
surface air outlets 4 as the side outlet air Ac, while another part of the sucked
air further passes the second heat exchanger 7 and is blown from the upper surface
air outlet 3 as the upper outlet air Ab.
[0043] The constitution of a refrigerant circuit of the whole air conditioner including
the indoor unit Z
3 is shown in Fig. 11. This air conditioner is composed of the indoor unit Z
3 and an outdoor unit Y connected to each other via refrigerant piping P. The outdoor
unit Y is provided with a compressor 9, a direction switching valve 10, an outdoor
heat exchanger 11 and an expansion valve 12, while the indoor unit Z
3 is provided with the first heat exchanger 6 and the second heat exchanger 8. In the
indoor unit of this embodiment, the first heat exchanger 6 and the second heat exchanger
7 are arranged such that the second heat exchanger 7 is positioned downstream of the
first heat exchanger 6 in the circulation direction of the refrigerant in the cooling
operation cycle.
[0044] Subsequently, the functions of the indoor unit Z
3 of this embodiment in the heating and cooling operations will be described.
[0045] In the indoor unit Z
3 of this embodiment, the second heat exchanger 7 is disposed on the side of the upper
surface air outlet 3, and no heat exchanger is provided on the side of side surface
air outlets 4. Therefore, in both of the heating operation and the cooling operation,
the upper outlet air Ab to be blown from the upper surface air outlet 3 is subjected
to heat exchange by the first heat exchanger 6 and the second heat exchanger 7, while
the side outlet air Ac to be blown from the side surface air outlets 4 is subjected
to heat exchange by only the first heat exchanger 6. As a result, a temperature difference
arises between the side outlet air Ac and the upper outlet air Ab. This indoor unit
Z
3 is intended to improve the comfortableness particularly in cooling, using this temperature
difference between the side outlet air Ac and the upper outlet air Ab efficiently.
[0046] That is, as shown in Fig. 13, in the cooling operation of the indoor unit Z
3, of the sucked air Aa, the side outlet air Ac to be blown from the side surface air
outlets 4 is subjected to a cooling action by only the first heat exchanger 6, and
the upper outlet air Ab to be blown from the upper surface air outlet 3 is subjected
to a cooling action by both of the first heat exchanger 6 and the second heat exchanger
7. Therefore, the upper outlet air Ab is set to a relatively low temperature, while
the side outlet air Ac is set to a relatively high temperature. As a result, cooler
air is blown to an upper part of the room, while relatively warm air is blown to a
lower part of the room. This realizes the "cooling a head and warming feet" ambience,
and a comfortable cooling sensation can be obtained by efficiently restraining cold
air from gathering at one's feet. That is, the operation that lays stress on the comfortableness
in cooling is realized.
[0047] On the other hand, in the heating operation of the indoor unit Z
3, as shown in Fig. 12, a high-temperature air subjected to heating by the first heat
exchanger 6 and the second heat exchanger 7 is blown from the upper surface air outlet
3 as the upper outlet air Ab. On the other hand, a relatively low-temperature air
heated by only the first heat exchanger 6 is blown from the side surface air outlets
4 as the side outlet air Ac. For that reason, if the comfortableness is desired also
in the heating operation, for example, the upper surface air outlet 3 may be closed
so that the output of the upper outlet air Ab from the upper surface air outlet 3
is controlled.
Fourth Embodiment (see Figs. 14-16)
[0048] Fig. 14 shows a refrigerant circuit of the whole air conditioner provided with an
indoor unit Z
4 of a fourth embodiment of the present invention. In the indoor unit Z
3 of the third embodiment, the refrigerant path is set so that the first heat exchanger
6 is positioned upstream of the heat exchanger 7 in the cooling cycle. Contrary to
this, in the indoor unit Z
4 of the fourth embodiment, a refrigerant path is set so that the first heat exchanger
6 is positioned downstream of the second heat exchanger 7 in the circulation direction
of the refrigerant in the cooling cycle.
[0049] Therefore, as shown in Figs. 15 and 16, in the same manner as in the indoor unit
Z
3 of the third embodiment, in both of the heating operation and the cooling operation,
the upper outlet air Ab to be output from the upper surface air outlet 3 is heated
or cooled by both the first heat exchanger 6 and the second heat exchanger 7, but
the side outlet air Ac to be output from the side surface air outlet 4 is heated or
cooled by only the first heat exchanger 6. Thus, a temperature difference arises between
the side outlet air Ac and the upper outlet air Ab. As a result, the operation that
particularly lays stress on the comfortableness in cooling is realized in the same
manner as in the indoor unit Z
3 of the third embodiment.
Fifth Embodiment (see Figs. 17-19)
[0050] This embodiment is directed to an indoor unit structured such that, in the same manner
as in the indoor unit Z
1 of the first embodiment, the first heat exchanger 6 is disposed in correspondence
with the air inlet 2 of the casing 1, and that, of the upper surface air outlet 3
and the right and left side surface air outlets 4, 4, the second heat exchangers 8
are provided for the respective side surface air outlets 4, 4 (see Fig. 2). Therefore,
with the operation of the fans 5, 5, the sucked air Aa sucked from the air inlet 2
passes the first heat exchanger 6 and then one part of the sucked air is blown as
it is from the upper surface air outlet 3 as the upper outlet air Ab, while another
part further passes the second heat exchanger 8 and is output from the side surface
air outlet 4 as the side outlet air Ac.
[0051] The constitution of a refrigerant circuit of the whole air conditioner including
the indoor unit Z
5 is shown in Fig. 17. This air conditioner is composed of the indoor unit Z
1 and an outdoor unit Y connected to each other via refrigerant piping P. A compressor
9, a direction switching valve 10, an outdoor-side heat exchanger 11 and an expansion
valve 12 are provided in the outdoor unit Y, while the indoor unit Z
5 is provided with the first heat exchanger 6 and the second heat exchangers 8.
[0052] In the indoor unit Z
5 of this embodiment, the first heat exchanger 6 is connected via an auxiliary expansion
valve 13 to the second heat exchangers 8, and the first heat exchanger 6 and the second
heat exchangers 8 are arranged such that the second heat exchangers 8 are located
upstream of the first heat exchanger 6 in the circulation direction of the refrigerant
in the cycle of cooling operation.
[0053] Operative relationships between the auxiliary expansion valve 13 and the main expansion
valve 12 in the outdoor unit Y are set in a relative manner. That is, in the heating
operation, the main expansion valve 12 is set to "throttled" and the auxiliary expansion
valve 13 is set to "full open". On the other hand, in the cooling operation, the main
expansion valve 12 is set to "slightly throttled" and the auxiliary expansion valve
13 is set to "throttled".
[0054] Subsequently, functions of the indoor unit Z
5 of this embodiment in the heating and cooling operations will be described.
[0055] As described above, in the heating operation, the main expansion valve 12 is set
to "throttled" and the auxiliary expansion valve 13 is set to "full open". Therefore,
as shown in Fig. 18, both of the first heat exchanger 6 and the second heat exchangers
8 function as compressors on the high-pressure side. Thus, a relatively low-temperature
air heated by only the first heat exchanger 6 is blown upward from the upper surface
air outlet 3 as the upper outlet air Ab, while a relatively high-temperature air heated
by both the first heat exchanger 6 and the second heat exchanger 8 is blown sideways
from the side surface air outlet 4 as the side outlet air Ac. Therefore, rising of
the air having a relatively high temperature in a lower part of the room is suppressed
by the air having a relatively low temperature in an upper part of the room, and a
"cooling a head and warming feet" ambience that is of an ideal temperature distribution
ambience is realized. Thereby, the comfortable heating sensation is obtained.
[0056] On the other hand, as described above, in the cooling operation, the main expansion
valve 12 is set to "slightly throttled" and the auxiliary expansion valve 13 is set
to "throttled". Therefore, as shown in Fig. 19, the first heat exchanger 6 functions
as an evaporator on the low-pressure side, while the second heat exchangers 8 function
as evaporators at an intermediate pressure between the high-pressure side and the
low-pressure side. Thus, a relatively low-temperature air cooled by only the first
heat exchanger 6 is blown upward from the upper surface air outlet 3 as the upper
outlet air Ab, while a relatively high-temperature air is blown sideways from the
side surface air outlets 4 as the side outlet air Ac, which was first cooled by the
first heat exchanger 6 and then cooled by the second heat exchanger 8 having a temperature
higher than the first heat exchanger 6 so that the temperature of the air is raised.
As a result, the "cooling a head and warming feet" ambience that is an ideal temperature
distribution ambience is realized. A comfortable cooling sensation is obtained by
controlling cold air remaining at one's feet efficiently.
Sixth Embodiment (see Figs. 20-22)
[0057] In the fifth embodiment, the indoor unit Z
5 is provided with the second heat exchangers 8 on the sides of the side surface air
outlets 4, and the second heat exchangers 8 are positioned upstream of the first heat
exchanger 6, with the auxiliary expansion valve 13 disposed therebetween, in the circulation
direction of the refrigerant in the cycle of cooling operation. On the other hand,
in an indoor unit Z
6 of a sixth embodiment, the second heat exchanger 7 is provided on the side of the
upper surface air outlet 3, and the heat exchanger 7 is disposed upstream of the first
heat exchanger 6 in the circulation direction of the refrigerant.
[0058] In the indoor unit Z
6 of this embodiment, operative relationships between the auxiliary expansion valve
13 and the main expansion valve 12 in the outdoor unit Y are set in a relative manner.
That is, in the heating operation, the main expansion valve 12 is set to "throttled"
and the auxiliary expansion valve 13 is set to "slightly throttled". On the other
hand, in the cooling operation, the main expansion valve 12 is set to "throttled"
and the auxiliary expansion valve 13 is set to "full open".
[0059] Next, the functions of the indoor unit Z
6 in the heating and cooling operations of this embodiment will be described.
[0060] As described above, in the heating operation, the main expansion valve 12 is set
to "throttled" and the auxiliary expansion valve 13 is set to "slightly throttled".
Therefore, as shown in Fig. 21, the first heat exchanger 6 functions as an evaporator
on the high-pressure side, and the second heat exchanger 7 functions as an evaporator
at an intermediate pressure between the high-pressure side and the low-pressure side.
Thus, the upper outlet air Ab blown from the upper surface air outlet 3 was heated
by the first heat exchanger 6 and then cooled by passing the second heat exchanger
functioning as the evaporator at an intermediate pressure to give a relatively low-temperature
air. Contrary to this, the side outlet air Ac blown sideways from the side surface
air outlet 4 was only heated by the first heat exchanger 6, and thus the temperature
of the air is relatively high. Therefore, the air having a relatively high temperature
is present in a lower part of the room, while in an upper part of the room, the air
having a relatively low temperature is present. As a result, the "cooling a head and
warming feet" state of an ideal temperature distribution is realized, and a comfortable
heating sensation is obtained by efficiently restraining cold air from gathering at
one's feet.
[0061] On the other hand, as described above, in the cooling operation, the main expansion
valve 12 is set to "throttled", and the auxiliary expansion valve 13 is set to "full
open". Therefore, as shown in Fig. 22, both of the first heat exchanger 6 and the
second heat exchanger 7 function as evaporators on the low-pressure side. Thus, the
upper outlet air Ab blown from the upper surface air outlet 3 was cooled by both of
the first heat exchanger 6 and the second heat exchanger 7, while the side outlet
air Ac blown from the side surface air outlets 4 was cooled by only the first heat
exchanger 6. Thus, the air having a relatively low temperature is present in the upper
part of the room, while the air having a relatively high temperature is present in
the lower part of the room. As a result, the "cooling a head and warming feet" ambience
that is an ideal temperature distribution ambience is realized, and a comfortable
cooling sensation is obtained by efficiently restraining cold air from gathering at
one's feet.
[0062] Further description will now be made with respect to examples not falling within
the scope of the appended claims.
[0063] In an example useful for understanding the present invention, the means for regulating
a temperature of either upper outlet air from the upper surface air outlet or side
outlet air from the side surface air outlet comprises a heater provided at the side
surface air outlet.
[0064] In this indoor unit, in the heating operation, the temperature of the air heated
by the heat exchanger and blown upward from the upper surface air outlet is lower
than that of the air heated by both the heat exchanger and the heater and blown sideways
from the side surface air outlet. Therefore, a relatively high-temperature air in
the lower part of the room is prevented from rising by a relatively low-temperature
air in the upper part of the room. This realizes "cooling a head and warming feet",
and a comfortable heating sensation is obtained.
[0065] On the other hand, in the cooling operation, a relatively high-temperature air cooled
by the heat exchanger and then heated by the heater is blown sideways from the side
surface air outlet. In contrast, a relatively low-temperature air only cooled by the
heat exchanger is blown from the upper surface air outlet. Therefore, the relatively
high-temperature air is present in the lower part of the room, and the relatively
low-temperature air is present in the upper part of the room. This realizes a "cooling
a head and warming feet" ambience that is of an ideal temperature distribution, and
a comfortable cooling sensation can be obtained, with cold air gathering at one's
feet suppressed efficiently.
[0066] In another example useful for understanding the present invention, the means for
regulating a temperature of either upper outlet air from the upper surface air outlet
or side outlet air from the side surface air outlet comprises a circulation system
which makes indoor air bypass the heat exchanger and blows indoor air toward the upper
surface and/or the side surface.
[0067] In the case where the indoor air is blown toward the upper surface of the casing
by the circulation system, in the heating operation, the air heated by the heat exchanger
and the indoor air from the circulation system are mixed and blown upward from the
upper surface air outlet, whereby the temperature of the air blown upward is relatively
low. On the other hand, a relatively high-temperature air heated by the heat exchanger
is let out through the side surface air outlet. Therefore, the relatively high-temperature
air in the lower part of the room is restrained from rising by the relatively low-temperature
air in the upper part of the room. This realizes "cooling a head and warming feet",
and a comfortable heating sensation is obtained. That is, an operation that places
importance on comfortableness in heating is obtained.
[0068] On the other hand, in the case where the indoor air is blown sideways by the circulation
system, in the cooling operation, a relatively low-temperature air cooled by the heat
exchanger is blown upward from the upper surface air outlet, while a relatively high-temperature
mixture of the air cooled by the heat exchanger and the indoor air from the circulation
system is blown from the side surface air outlet. This controls cold air remaining
at one's heat as much as possible, and the operation that lays stress on the comfortableness
in cooling is realized.
First Example (see Fig. 23)
[0069] In the indoor units Z
1-Z
6 of the first to sixth embodiments, improvement in the comfortableness in cooling
or heating was contrived by additionally providing the second heat exchanger 7 or
8. On the other hand, in an indoor unit Z
7 of a first example useful for understanding the present invention, the comfortableness
in cooling or heating is achieved by providing heaters 15 on the air outlet sides
of the fans 5.
[0070] That is, in the indoor unit Z
7, as shown in Fig. 23, only the first heat exchanger 6 is disposed on the suction
side of the fans 5. On the other hand, on the discharge side of the fans 5, no heat
exchangers are provided but the heaters 15 are disposed at the side surface air outlets
4. The heaters 15 are energized in both the heating operation and the cooling operation.
[0071] With the above construction, in the heating operation, a relatively high-temperature
air first heated by the first heat exchanger 6 and further heated by the heaters 15
is blown from the side surface air outlets 4 as the side outlet air Ac, and a relatively
low-temperature air heated only by the first heat exchanger 6 is blown from the upper
surface air outlet 3. As a result, the air having a relatively low temperature is
present in the upper part of the room, while the air having a relatively high temperature
is present in the lower part of the room, so that the relatively high-temperature
air in the lower part of the room is restrained from rising by the relatively low-temperature
air in the upper part of the room. Therefore, a "cooling a head and warming feet"
ambience is realized, and a comfortable heating sensation is obtained.
[0072] In the cooling operation, a relatively high-temperature air cooled by the first heat
exchanger 6 and then heated by the heater 15 is blown from the side surface air outlet
4 as the side outlet air Ac, while a relatively low-temperature air only cooled by
the first heat exchanger 6 is blown from the upper surface air outlet 3. As a result,
the air having a relatively high temperature is present in the lower part of the room,
while the air having a relatively low temperature is present in the upper part of
the room. Therefore, a "cooling a head and warming feet" ambience that is an ideal
thermal space is realized. Accordingly, a comfortable cooling sensation can be obtained,
with the cold air gathering at one's feet efficiently suppressed.
Second Example (see Fig. 24)
[0073] Fig. 24 shows an indoor unit Z
8 of a second example useful for understanding the present invention. In this indoor
unit Z
8, differently from the indoor units Z
1-Z
7 of the first to sixth embodiments and first example in which the discharge temperatures
themselves of the upper outlet air Ab and the side outlet air Ac are controlled, the
indoor air (namely, air having a temperature lower than that of the conditioned air
blown from the indoor unit in the heating operation, and air having a temperature
higher than that of the conditioned air in the cooling operation) is made to detour
or bypass the heat exchanger 6 and return to the inside of the room. By so doing,
temperature adjustment between the upper outlet air Ab and the side outlet air Ac
is performed to obtain the comfortableness in the air conditioning.
[0074] That is, as shown in Fig. 24, the indoor unit Z8 has a circulation system X composed
of a curved bypass 20 extending from the upper part of the air inlet 2 to the vicinity
of the upper surface air outlet 3 of the upper surface of the casing 1 and a fan 21
disposed within the bypass 20.
[0075] With this constitution, particularly in the heating operation, the upper outlet air
Ab heated by the first heat exchanger 6 and then blown upward from the upper surface
air outlet 3 is mixed with the indoor air Ab' blown upward from the vicinity of the
upper surface air outlet 3 by the circulation system X, whereby the upper discharge
temperature is made relatively low. On the other hand, the air heated by the first
heat exchanger, which has a relatively high temperature, is blown from the side surface
air outlets 4 as the side outlet air Ac. As a result, the air in the lower part of
the room, which has a relatively high temperature, is prevented from going up by the
air in the upper part of the room, which has a relatively low temperature. Therefore,
"cooling a head, and warming feet" is realized, and a comfortable cooling sensation
is obtained. During the cooling operation, the operation of the circulation system
X is stopped.
Third Example (see Fig. 25)
[0076] Fig. 25 shows an indoor unit Z
9 of a third example useful for understanding the present invention. The indoor unit
Z
8 of the second example lays stress on the comfortableness in the heating operation,
while this indoor unit Z
9 lays stress on the comfortableness in the cooling operation.
[0077] That is, on its right and left sides, the indoor unit Z
9 has circulation systems X each composed of a bypass 22 detouring the heat exchanger
6 to provide communication between the air inlet 2 and the vicinity of the corresponding
side surface air outlet 4, and a fan 23 provided within the bypass 22.
[0078] Therefore, in the cooling operation, a mixture of the side outlet air Ac cooled by
the first heat exchanger 6 and blown from the side surface air outlet 4 and the indoor
air Ac' blown from the vicinity of the side surface air outlet 4, which has a relatively
high temperature, is blown sideways of the indoor unit Z
8. Contrary to this, upward of the indoor unit Z
9, the air cooled by the heat exchanger 6, which has a low temperature, is blown as
it is from the upper surface air outlet 3 as the upper outlet air Ab. As a result,
the air having a relatively low temperature is present in the upper part of the room,
while the air having a relatively high temperature is present in the lower part of
the room. Therefore, "cooling a head and warming feet", which is the ideal temperature
distribution, is realized, and a comfortable cooling sensation can be obtained without
remaining of cold air at one's feet.