U.S. patent application number 11/028646 was filed with the patent office on 2006-02-16 for operation control method for unitary air conditioner.
This patent application is currently assigned to LG Electronics Inc.. Invention is credited to Yoon-Jei Hwang, Seung-Youp Hyun, Won-Hee Lee, Jae-Hoon Sim.
Application Number | 20060032252 11/028646 |
Document ID | / |
Family ID | 36076842 |
Filed Date | 2006-02-16 |
United States Patent
Application |
20060032252 |
Kind Code |
A1 |
Lee; Won-Hee ; et
al. |
February 16, 2006 |
Operation control method for unitary air conditioner
Abstract
The present invention discloses an operation control method for
a unitary air conditioner. The present invention improves the load
response capabilities of compressors by operating them at
three-stages of the maximum operation, minimum operation and
intermediate operation using one or more compressors, and improves
the energy efficiency and the amenity by determining the
three-stage operation mode based on the previous operation
status.
Inventors: |
Lee; Won-Hee; (Seoul,
KR) ; Hwang; Yoon-Jei; (Seoul, KR) ; Hyun;
Seung-Youp; (Seoul, KR) ; Sim; Jae-Hoon;
(Seoul, KR) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Assignee: |
LG Electronics Inc.
|
Family ID: |
36076842 |
Appl. No.: |
11/028646 |
Filed: |
January 5, 2005 |
Current U.S.
Class: |
62/175 ;
62/228.5; 62/510 |
Current CPC
Class: |
F25B 2600/0251 20130101;
F25B 49/022 20130101; F25B 2400/0751 20130101; F24F 11/65 20180101;
F24F 11/30 20180101; F25B 13/00 20130101; F24F 11/62 20180101; F25B
2700/2104 20130101 |
Class at
Publication: |
062/175 ;
062/228.5; 062/510 |
International
Class: |
F25B 7/00 20060101
F25B007/00; F25D 17/00 20060101 F25D017/00; F25B 1/00 20060101
F25B001/00; F25B 49/00 20060101 F25B049/00; F25B 1/10 20060101
F25B001/10 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 14, 2004 |
KR |
64106/2004 |
Claims
1. An operation control method for a unitary air conditioner with
one or more compressors, comprising the steps of: operating the
compressors for a predetermined time by a user's selecting a low
cold temperature cooling mode or a high cold temperature cooling
mode; and operating the compressors in either the minimum operation
mode or the intermediate operation mode when a low cold temperature
signal is inputted from a thermostat by the selection of the low
cold temperature cooling mode.
2. The method of claim 1, further comprising the step of operating
both smaller capacity and larger capacity compressors in the
maximum operation mode when a high cold temperature signal is
inputted from the thermostat by the selection of the high cold
temperature cooling mode.
3. The method of claim 1, wherein the minimum operation mode allows
to operate only the compressor with a smaller capacity out of the
one or more compressors, and the intermediate operation mode allows
to operate only the compressor with a larger capacity out of the
one or more compressors.
4. The method of claim 1, wherein the step of operating the
compressors according to a low cold temperature signal from the
thermostat further comprises the step of checking the previous
operation status of the cooling mode.
5. The method of claim 4, wherein the previous operation status is
determined based on a gap between a room temperature and a desired
temperature or an outdoor temperature.
6. The method of claim 1, wherein the minimum or intermediate
operation mode is determined by judging the size of the load at the
indoor side.
7. The method of claim 6, wherein the size of the load at the
indoor side is a gap between a room temperature and a desired
temperature.
8. The method of claim 7, wherein, when the load at the indoor side
is large, the load response capabilities is increased using only
the larger capacity compressor out of the one or more
compressors.
9. The method of claim 7, wherein, when the load at the indoor side
is small, the power consumption is reduced using only the smaller
capacity compressor out of the one or more compressors.
10. An operation control method for a unitary air conditioner with
one or more compressors, comprising the steps of: a user's
selecting a low cold temperature cooling mode or a high cold
temperature cooling mode; when a high cold temperature signal is
inputted from a thermostat by selecting the high cold temperature
cooling mode, operating both smaller capacity and larger capacity
compressors in the maximum operation mode; and when a low cold
temperature signal is inputted from the thermostat by selecting the
low cold temperature cooling mode, checking the previous operation
status based on the size of the load at the indoor side and
operating the compressors in either the minimum operation mode or
the intermediate operation mode.
11. The method of claim 10, further comprising the steps of:
detecting a room temperature and comparing the room temperature
with a desired temperature; and judging the size of the load at the
indoor side based on the result of the comparison between the room
temperature and the desired temperature.
12. An operation control method for a unitary air conditioner with
one or more compressors, comprising the steps of: selecting a
cooling mode and generating a low cold temperature signal from a
thermostat; operating the compressor with a larger capacity
according to the low cold temperature signal; comparing a room
temperature and a desired temperature after a lapse of a
predetermined time; and when the thermostat generates a compressor
on/off control signal for generating a high cold temperature signal
based on the result of the comparison, operating all of the one or
more compressors.
13. The method of claim 12, further comprising the steps of:
comparing a room temperature and a desired temperature after
operating the smaller capacity and larger capacity compressors for
a predetermined time; and when the thermostat generates a
compressor on/off control signal for generating a low cold
temperature signal based on the result of the comparison, operating
the larger capacity compressor.
14. The method of claim 13, further comprising the steps of:
comparing a room temperature and a desired temperature after
operating the larger capacity compressor for a predetermined time;
and when the thermostat generates a compressor on/off control
signal for stopping the operation of the larger capacity compressor
based on the result of the comparison, stopping the operation of
the larger capacity compressor; when the thermostat generates a
compressor on/off control signal for generating a low cold
temperature signal after a predetermined of time, operating the
smaller capacity compressor.
15. The method of claim 14, further comprising the steps of:
comparing a room temperature and a desired temperature after
operating the smaller capacity compressor for a predetermined time;
and when the thermostat generates a compressor on/off control
signal for stopping the operation of the smaller capacity
compressor based on the result of the comparison, stopping the
operation of the smaller capacity compressor; when the thermostat
generates a compressor on/off control signal for generating a low
cold temperature signal after a predetermined of time, operating
the smaller capacity compressor.
16. The method of claim 12, further comprising the steps of:
comparing a room temperature and a desired temperature after
operating the smaller capacity and larger capacity compressors for
a predetermined time; and when the thermostat generates a
compressor on/off control signal for stopping the operation of the
smaller capacity and larger capacity compressors based on the
result of the comparison, stopping the operation of the smaller
capacity and larger capacity compressors.
17. The method of claim 16, further comprising the steps of:
comparing a room temperature and a desired temperature after
operating the smaller capacity and larger capacity compressors for
a predetermined time; and when the thermostat generates a
compressor on/off control signal for generating a low cold
temperature signal based on the result of the comparison, operating
the larger capacity compressor.
18. An operation control method for a unitary air conditioner with
one or more compressors, comprising the steps of: generating a high
cold temperature signal from a thermostat when a cooling mode is
selected; operating all of the one or more compressors according to
the low cold temperature signal; comparing a room temperature and a
desired temperature after operating the compressors for a
predetermined time; when the thermostat generates a compressor
on/off control signal for stopping the operation of the compressors
based on the result of the comparison, stopping the operation of
the compressors; comparing a room temperature and a desired
temperature after a predetermined time; and when the thermostat
generates a compressor on/off control signal for generating a low
cold temperature signal based on the result of the comparison,
operating the larger capacity compressor out of the one or more
compressors.
19. The method of claim 18, further comprising the steps of:
comparing a room temperature and a desired temperature after
operating the smaller capacity and larger capacity compressors for
a predetermined time; and when the thermostat generates a
compressor on/off control signal for generating a low cold
temperature signal based on the result of the comparison, operating
the larger capacity compressor.
20. The method of claim 19, further comprising the steps of:
comparing a room temperature and a desired temperature after
operating the larger capacity compressor for a predetermined time;
and when the thermostat generates a compressor on/off control
signal for stopping the operation of the larger capacity compressor
based on the result of the comparison, stopping the operation of
the larger capacity compressor; comparing a room temperature and a
desired temperature after a predetermined time, and when the
thermostat generates a compressor on/off control signal for
generating a low cold temperature signal after a predetermined of
time, operating the smaller capacity compressor.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a unitary air conditioner,
and more particularly, to an operation control method for a unitary
air conditioner which improves the load response capabilities of
compressors and improves energy efficiency and amenity.
[0003] 2. Description of the Background Art
[0004] Generally, a unitary air conditioning system is a kind of
centralized cooling and heating system which creates a hot air or
hot air in one place using a cooling and heating system and
supplies it to an individual space through a duct.
[0005] FIG. 1 is a schematic view illustrating a conventional
unitary air conditioner of heat pump type using a cooling
cycle.
[0006] FIG. 2 is a system view of the conventional unitary air
conditioner of FIG. 1.
[0007] As shown in FIGS. 1 and 2, the conventional unitary air
conditioner comprises one outdoor unit 1 fixedly disposed outside a
building, a cold and hot air unit 2 connected to a first exchange
1b of the outdoor unit 1 and fixedly disposed in the basement,
outbuilding, etc. of the basement, an air supply duct 3 and an
exhaust duct 4 connected by a refrigerant pipe to an air supplying
opening and an exhaust opening, respectively, of the cold and hot
air unit 2 and separately buried in the wall body of each floor of
the building and region controllers 5a to 5d disposed in the middle
of the air supply duct 3 and exhaust duct 4 and discriminating air
supply and air exhaustion to each floor.
[0008] The outdoor unit 1 comprises one or more compressor 1a
disposed inside a case and compressing a refrigerant gas, a firs
heat exchange 1b connected to the compressor 1a by a refrigerant
pipe and condensing the refrigerant gas (in a cooling operation) or
absorbing a latent heat (in a heating operation), an inflating
device 1c reducing and inflating the pressure of the refrigerant
gas, and an outdoor fan (not shown) supplying an external air to
the first heat exchange and increasing the heat exchange
performance of the heat exchange 1b.
[0009] The cold and hot air unit 2 comprises a second heat exchange
2a disposed inside a case and connecting one end thereof to the
first heat exchange 1b and the other end to the expansion device 1c
simultaneously and a supply ventilating fan (not shown) guiding a
hot air or hot air to the air supply duct 3. Further, the case of
the cold and hot air unit generally has an air channel of `U` shape
formed therein so as to receive the second heat exchange 2a and the
supply ventilating fan (not shown), the air supply duct 3 and the
exhaust duct 4 being connected respectively to the air supply side
and exhaust side of the air channel.
[0010] The air supply duct 3 and the exhaust duct 4, as stated
above, are connected to the air supplying opening and exhaust
opening of the cold and hot air unit 2 and separately buried in
corresponding regions Z1 and Z2. The air supply duct and 3 and the
exhaust duct 4 are provided with a discharge opening 3a supplying
cold air or hot air to the corresponding regions and a suction
opening 4a sucking cold air or hot air to circulate indoor air.
[0011] The region controllers 5a to 5d are a kind of valves which
are disposed in the middle of the air supply duct 3 and of the
exhaust duct buried in the corresponding regions Z1 and Z2 so as to
supply cold air or hot air to the corresponding regions separately.
They are connected to a control section (not shown) so that they
can be automatically turned on/off by detecting the temperature,
humidity, etc. of the corresponding regions and comparing the
detected values with set values, or they are configured to be
operated manually.
[0012] FIG. 3 is an exemplified view illustrating the operating
mode of a compressor being determined through a thermostat in the
conventional unitary air conditioner.
[0013] As shown in FIG. 3, the unitary air conditioner
conventionally commercialized operates the compressor in the
minimum operation mode or in the maximum operation mode by
controlling the indoor unit or outdoor unit by a low cold
temperature or high cold temperature operation control signal
provided from the thermostat.
[0014] For example, in case the unitary air conditioner is a
single-stage model, it conducts only the operation (such as the
maximum operation) set according to an operation control signal
provided from the thermostat. Further, in case the unitary air
conditioner is a two-stage model, when a high cold temperature
operation control signal is provided from the thermostat, both
indoor unit and outdoor unit conduct their operation in the minimum
operation mode.
[0015] As described above, although the conventional unitary air
conditioner uses two compressors, it operates only either the
compressor in the minimum operation mode or in the maximum
operation mode. Therefore, the conventional unitary air conditioner
has the defect of decreasing the load response capabilities of the
compressors and of increasing of power consumption by operating the
compressors only in the two-stage operation mode.
SUMMARY OF THE INVENTION
[0016] Therefore, an object of the present invention is to provide
an operation control method for a unitary air conditioner which is
able to improve the load response capabilities of compressors by
operating the compressors in the three-stage operation mode upon
driving one or more compressors.
[0017] It is another object of the present invention to provide an
operation control method for a unitary conditioner which improves
energy efficiency and amenity by checking the previous operation
status of the compressors and determining the operation mode of the
compressors based on the previous operation status.
[0018] There is provided an operation control method for a unitary
air conditioner with one or more compressors, in accordance with
the present invention, comprises the steps of: operating the
compressors for a predetermined time by a user's selecting a low
cold temperature cooling mode or a high cold temperature cooling
mode; and operating the compressors in either the minimum operation
mode or the intermediate operation mode according to a low cold
temperature signal generated from a thermostat by the selection of
the low cold temperature cooling mode.
[0019] There is provided an operation control method for a unitary
air conditioner with one or more compressors, in accordance with
the present invention, comprises the steps of: a user's selecting a
low cold temperature cooling mode or a high cold temperature
cooling mode; when a high cold temperature signal is inputted from
a thermostat by selecting the high cold temperature cooling mode,
operating the compressors in the maximum operation mode; and when a
low cold temperature signal is inputted from the thermostat by
selecting the low cold temperature cooling mode, checking the
previous operation status based on the size of the load at the
indoor side and operating the compressors in either the minimum
operation mode or the intermediate operation mode.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The accompanying drawings, which are included to provide a
further understanding of the invention and are incorporated in and
constitute a part of this specification, illustrate embodiments of
the invention and together with the description serve to explain
the principles of the invention.
[0021] In the drawings:
[0022] FIG. 1 is a schematic view illustrating a conventional
unitary air conditioner of heat pump type using a cooling
cycle;
[0023] FIG. 2 is a system view of the conventional unitary air
conditioner involved with FIG. 2;
[0024] FIG. 3 is an exemplified view illustrating the operating
mode of a compressor being determined through a thermostat in the
conventional unitary air conditioner;
[0025] FIG. 4 is a flow chart of one embodiment of an operation
control method for a unitary air conditioner in accordance with the
present invention;
[0026] FIGS. 5A and 5B are flow charts of another embodiment of an
operation control method for a unitary air conditioner in
accordance with the present invention;
[0027] FIGS. 6A and 6B are flow charts of yet another embodiment of
an operation control method for a unitary air conditioner in
accordance with the present invention;
[0028] FIG. 7 is a graph illustrating the comparison of changes in
indoor air temperature between the present invention and the
conventional art; and
[0029] FIG. 8 is a comparison chart illustrating load response
capabilities and power consumption with respect to the present
invention and the conventional art.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] Hereinafter, preferred embodiments relating to an operation
control method for a unitary air conditioner with one or more
compressor, which is able to increase the energy efficiency with a
reduction of power consumption and improve the amenity a user feels
with an improvement of response capabilities to a load, in
accordance with the present invention will be described in detail
with reference to the accompanying drawings. Although the
embodiments of the present invention have been described with
respect to a unitary air conditioner with two compressors having a
different capacity from each other for convenience of explanation,
it also may be applicable to a unitary air conditioner with one or
more compressor.
[0031] A system for control the operation of a unitary air
conditioner in accordance with the present invention may comprise
two compressors with a different capacity, a heat exchange, a fan,
a fan motor, an accumulator, etc. At this moment, in the present
invention, a three-stage operation is conducted using two
compressors with a different capacity while using a conventionally
used two-stage thermostat as it is. In other words, the unitary air
conditioner is operated in the maximum operation mode by operating
both of the two compressors, or is operated in the intermediate
operation mode (60% operation) by operating only the compressor
with a large capacity out of the two compressors, or is operated in
the minimum operation mode (40% operation) by operating only the
compressor with a smaller capacity out of the two compressors.
[0032] The embodiments relating to the operation control method for
a unitary air conditioner of the present invention in accordance
with the aforementioned construction will be described below.
[0033] FIG. 4 is a flow chart of one embodiment of an operation
control method for a unitary air conditioner in accordance with the
present invention.
[0034] As shown in FIG. 4, the operation control method for a
unitary air conditioner, the unitary air conditioner being provided
with two compressors having a different capacity, in accordance
with the present invention, comprises the steps of: operating one
or two of the compressors for a predetermined time by a user's
selecting a low cold temperature cooling mode or a high cold
temperature cooling mode (S41); detecting a room temperature and
comparing the room temperature with a desired temperature (S42 and
S43); judging the size of a load at the indoor side based on the
result of comparison between the room temperature and the desired
temperature (S44); when a low cold temperature signal Y1 is
inputted from a thermostat by selecting the low cold temperature
cooling mode, checking the previous operation status based on the
size of the load at the indoor side and operating the compressor in
either the minimum operation mode or the intermediate operation
mode (S46 and S47); when a high cold temperature signal Y2 is
inputted from the thermostat by the user's selecting the cooling
mode, operating both compressors in the maximum operation mode
(S45). In other words, in the present invention, when a low cold
temperature signal is generated from the thermostat, the size of
the load at the indoor side is judged to thus determine the
operation of the compressors in the minimum or intermediate
operation mode, and the size of the load at the indoor side means a
gap between the room temperature and the desired temperature.
Further, the previous operation status is determined based on a gap
between the room temperature and the desired temperature, an
outdoor temperature or the like.
[0035] Therefore, in the operation control method for the unitary
air conditioner in accordance with the present invention, when a
low cold temperature signal is generated from the thermostat, the
minimum operation mode allows to operate only the compressor with a
smaller capacity out of the two compressors, and the intermediate
operation mode allows to operate only the compressor with a larger
capacity out of the two compressors. Hence, when the indoor side
load is large, only the larger capacity compressor (60% operation)
is used to thus increase the response capabilities to the load, or
when the indoor side load is small, only the smaller capacity
compressor (40% operation) is used to thus reduce the power
consumption.
[0036] The embodiments of the operation control method for the
unitary air conditioner will be described in more detail.
[0037] FIGS. 5A and 5B are flow charts of another embodiment of an
operation control method for a unitary air conditioner in
accordance with the present invention.
[0038] As shown in FIGS. 5A and 5B, upon an initial start-up, the
unitary air conditioner generates a low cold temperature signal
from a thermostat according to a user's selection of a cooling
mode, and operates a larger capacity compressor (e.g., 60%
operation) according to the low cold temperature signal (S51 to
S53).
[0039] Thereafter, when a predetermined time elapses during which
an indoor load is eliminated, a room temperature and a desired
temperature are compared, and then when the thermostat generates a
compressor on/off control signal Y2 for generating a low cold
temperature based on the result of the comparison, both smaller
capacity and large capacity compressors are operated (e.g., 100%
operation) to thus eliminate the indoor load (S54 to S56).
[0040] Thereafter, when a predetermined time elapses since the
smaller capacity and larger capacity compressors have been
operated, a room temperature and a desired temperature are compared
again, and then when the thermostat generates a compressor on/off
signal Y1 for generating a low cold temperature signal based on the
result of the comparison, the larger capacity compressor is
operated (e.g., 60% operation) (S57 to S59).
[0041] When a predetermined time elapses since the larger capacity
compressor has been operated, a room temperature and a desired
temperature are compared, and then when the thermostat generates a
compressor on/off control signal for stopping the operation of the
compressor based on the result of the comparison, the operation of
the larger capacity compressor is stopped (S60 to S62).
[0042] Thereafter, after the lapse of a predetermined time, when
the thermostat generates a compressor on/off signal Y1 for
generating a low cold temperature signal, the smaller capacity
compressor is operated (S63 to S65). In other words, when the
thermostat generates a stop signal after generating a low cold
temperature signal Y1 and then generates a low cold temperature
signal Y1 again, it is judged that the load is eliminated to some
extent and thus only the smaller capacity compressor for executing
the minimum operation is operated.
[0043] Since it is judged that the indoor load is eliminated to
some extent afterwards, only the smaller capacity compressor is
generated upon generating a low cold temperature signal Y1 (S66 and
S67). That is, when a predetermined time elapses since the smaller
capacity compressor has been operated, a room temperature and a
desired temperature are compared, and then when the thermostat
generates a compressor on/off control signal for stopping the
operation of the compressor based on the result of the comparison,
the operation of the smaller capacity compressor is stopped. Then,
after a predetermined time, when the thermostat generates a
compressor on/off signal for generating a low cold temperature
signal Y1, the smaller capacity compressor is operated.
[0044] Meanwhile after a lapse of a predetermined time since the
smaller capacity and larger capacity compressors have been operated
(S56), a room temperature and a desired temperature are compared
(S57). And, when the thermostat generates a compressor on/off
control signal for stopping the operation of the compressors based
on the result of the comparison, the operation of the larger
capacity and smaller capacity compressors is stopped (S68). when a
predetermined time elapses since the larger capacity and smaller
capacity compressors are stopped, a room temperature and a desired
temperature are compared, and then when the thermostat generates a
compressor on/off control signal for generating a low cold
temperature signal Y1 based on the result of the comparison, the
larger capacity compressor is operated (S57 to S59). That is, when
a low cold temperature signal is generated by the elimination of
the load after a lapse of a predetermined time since the larger
capacity compressor and the smaller capacity compressor have been
operated according to a high cold temperature signal, or when a low
cold temperature signal is generated after the compressors are
stopped for a predetermined time, the larger capacity compressor is
operated to eliminate the load.
[0045] According to yet another embodiment of the present
invention, the thermostat may generate a high cold temperature
signal at an early stage. The algorithm of this embodiment of the
present invention which generates a high cold temperature signal at
an early stage will be described below.
[0046] FIGS. 6A and 6B are flow charts of yet another embodiment of
an operation control method for a unitary air conditioner in
accordance with the present invention.
[0047] As shown in FIGS. 6A and 6B, when the cooling mode is
selected by a user, the thermostat generates a high cold
temperature signal, and operates smaller capacity and larger
capacity compressors according to the high cold temperature signal
(S81 to S83).
[0048] When a predetermined time elapses since the smaller capacity
and larger capacity compressors have been operated, a room
temperature and a desired temperature are compared, and then when
the thermostat generates a compressor on/off control signal for
stopping the operation of the compressors based on the result of
the comparison, the operation of the smaller capacity and larger
capacity compressors is stopped (S84 to S86).
[0049] Thereafter, when a predetermined time elapses since the
smaller capacity and larger capacity compressors have been stopped,
a room temperature and a desired temperature are compared, and then
when the thermostat generates a compressor on/off control signal
for generating a low cold temperature signal based on the result of
the comparison, the larger capacity compressor is operated (S87 to
S89).
[0050] When a predetermined time elapses since the smaller capacity
and larger capacity compressors have been operated (S83), a room
temperature and a desired temperature are compared (S84), and then
when the thermostat generates a compressor on/off control signal
for generating a low cold temperature signal based on the result of
the comparison, the operation of the larger capacity compressor is
stopped (S88 to S89).
[0051] Next, when a predetermined time elapses since the larger
capacity compressor has been operated, a room temperature and a
desired temperature are compared, and then when the thermostat
generates a compressor on/off control signal for stopping the
operation of the compressor based on the result of the comparison,
the operation of the larger capacity compressor is stopped (S90 to
S92).
[0052] After a predetermined time, a room temperature and a desired
temperature are compared again, and then when the thermostat
generates a compressor on/off control signal for generating a low
cold temperature signal based on the result of the comparison, the
operation of the smaller capacity compressor is stopped (S93 to
S95).
[0053] Thereafter, when the user enters a cooling mode end signal,
the operation of the compressor is finished (S96).
[0054] FIG. 7 is a graph illustrating the comparison of changes in
indoor air temperature between the present invention and the
conventional art.
[0055] As shown in FIG. 7, it can be seen that the unitary air
conditioner using a three-stage algorithm in accordance with the
present invention has an overally smaller gradient of indoor
temperature than the conventional art. This makes the user feel
pleasant with the improvement of the compressors' load response
capabilities.
[0056] FIG. 8 is a comparison chart illustrating load response
capabilities and power consumption with respect to the present
invention and the conventional art.
[0057] As shown in FIG. 8, it can be seen that the unitary air
conditioner using the three-stage algorithm in accordance with the
present invention increases the energy efficiency with a reduction
of power consumption and improves the amenity with an improvement
of response capabilities to a load.
[0058] As described in detail above, the present invention has the
effect of improving the load response capabilities of the
compressors by operating the compressors in the three-stage
operation mode upon driving one or more compressors. Further, the
present invention has the effect of improving energy efficiency and
amenity with a reduction of power consumption since the operation
mode of the compressors is determined by judging the previous
operation status according to the size of the load at the indoor
side upon a low cold temperature operation.
[0059] As the present invention may be embodied in several forms
without departing from the spirit or essential characteristics
thereof, it should also be understood that the above-described
embodiments are not limited by any of the details of the foregoing
description, unless otherwise specified, but rather should be
construed broadly within its spirit and scope as defined in the
appended claims, and therefore all changes and modifications that
fall within the metes and bounds of the claims, or equivalence of
such metes and bounds are therefore intended to be embraced by the
appended claims.
* * * * *