Methods and apparatus for controlling the temperatures of a plurality of rooms

The temperatures of a plurality of rooms are controlled by a refrigerant cycle which enables a user to select desired room temperatures and one of the following operating modes: (i) supplying hot refrigerant to the indoor heat exchangers of all rooms, (ii) supplying cold refrigerant to the indoor heat exchangers of all rooms, and (iii) supplying hot refrigerant to an indoor heat exchanger of one room and cold refrigerant to an indoor heat exchanger of another room.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a control apparatus of an air conditioner 
and a method thereof for simultaneously cooling and heating a plurality of 
room spaces, or individually and separately heating and cooling room 
spaces by utilizing one outdoor unit. 
2. Description of the Prior Art 
Generally, an air conditioner comes in two types, i.e., one is a heating 
apparatus for heating cold air in a room and the other is a cooling 
apparatus for cooling warm air in the room. 
Of course, there is an apparatus having dual functions of heating and 
cooling the room, and in addition an air-cleaning function for cleaning 
polluted indoor air. 
Referring to FIG. 1, there is illustrated a conventional air conditioner of 
a cooling-only apparatus. 
As shown in FIG. 1, when refrigerant compressed by a compressor 1 to a 
gaseous state at high temperature and high pressure is infused to an 
outdoor heat exchanger 2, the outdoor heat exchanger 2 serves to 
heat-exchange the same with air blown by an outdoor fan (not shown), and 
forcibly cool and liquify the refrigerant. 
The fluid refrigerant of low temperature and high pressure liquefied at the 
outdoor heat exchanger 2 passes through an expansion valve 3 for expanding 
the refrigerant to an evaporating pressure, reduced in pressure to become 
atomized refrigerant of low pressure and low temperature and is infused to 
an indoor heat exchanger 4. 
Accordingly, the atomized refrigerant reduced to low pressure and low 
temperature at the expansion valve 3 is evaporated in the course of 
passing through various pipes and takes heat from the air blown by an 
indoor fan (not shown) in the course of being gasified, to thereby cool 
the air in a room. 
The cooled air is in turn discharged indoors to thereby perform a cooling 
operation. The gaseous refrigerant of low pressure and low temperature 
cooled at the indoor heat exchanger 4 is in turn fed into the compressor 1 
and circulates repeatedly through a cooling loop as illustrated by 
continuous line arrows in FIG. 1. 
However, there is a problem in the conventional air conditioner for 
performing the cooling operation according to the cooling cycle thus 
described, in that various rooms cannot be simultaneously cooled because 
the outdoor unit controls only one indoor unit, and an indoor heating 
operation cannot be performed. 
By way of another prior art utilizing an air conditioner for performing 
dual operations of cooling or heating a room (see FIG. 2), when 
refrigerant compressed to a gaseous state of high temperature and high 
pressure at the compressor is infused into the outdoor heat exchanger 2 
according to the control of a four-way valve 5, as illustrated in FIG. 2, 
the outdoor-heat exchanger 2 serves to forcibly cool and liquify the 
gaseous refrigerant. 
The fluid refrigerant of low temperature and high pressure liquefied by the 
outdoor heat exchanger 2 passes through the expansion valve 3 via one way 
valve 7 to thereby be reduced to atomized refrigerant of low pressure and 
low temperature which is infused into the indoor heat exchanger 4. 
Accordingly, the atomized refrigerant in the indoor heat exchanger 4 takes 
the heat from the air blown by the indoor fan to thereby cool the air in 
the room when the atomized refrigerant passes through various pipes and is 
vaporized and is finally gasified. The cooled air is discharged indoors to 
thereby perform the cooling operation. The gasified refrigerant of low 
pressure and low temperature cooled by the indoor heat exchanger 4 is in 
turn fed into the compressor 1 and circulates repeatedly through a cooling 
loop as illustrated by solid line arrows in FIG. 2, thereby performing the 
indoor cooling operation. 
Meanwhile, in case of heating, when the refrigerant compressed to gaseous 
state of high pressure and high temperature by the compressor 1 is infused 
into the indoor heat exchanger 4 according to the control of the four way 
valve 5, the indoor heat exchanger 4 serves to heat-exchange the air blown 
by the indoor fan, to thereby cool the refrigerant to room temperature and 
high pressure. Thus, the heated air is discharged indoors to perform the 
heating operation. 
The refrigerant liquefied by the indoor heat exchanger 4 is reduced to 
refrigerant of low temperature and low pressure by the expansion valve 3 
and an expansion valve 6 and is then infused into the outdoor heat 
exchanger 2. 
Accordingly, the outdoor heat exchanger 2 serves to heat-exchange the 
refrigerant reduced in pressure at the expansion valve 3 and the expansion 
valve 6 by way of the air blown by the outdoor fan, thereby cooling the 
refrigerant. 
The gasified refrigerant of low temperature and low pressure cooled by the 
outdoor heat exchanger 2 is in turn fed into the compressor 1 and 
circulates repeatedly through a heating loop as illustrated by dotted line 
arrows in FIG. 2, thereby performing an indoor heating operation. 
However, there is a problem in the air conditioner depicted in FIG. 2 in 
that heating cannot be performed during the cooling operation, and cooling 
cannot be performed during the heating operation, thereby making it 
impossible to cater to various demands by consumers and to simultaneously 
perform the heating and the cooling operations, although there is an 
advantage in that both heating and cooling can be executed by one outdoor 
unit controlling one indoor unit. 
By way of still another prior art involving a multipurpose air conditioner 
for performing simultaneous cooling of various rooms shown in FIG. 3, when 
refrigerant compressed to a gaseous state of high temperature and high 
pressure by the compressor 1 is introduced to the outdoor heat exchanger 
2, the outdoor heat exchanger 2 serves to cool and liquify the gaseous 
refrigerant by way of the air blown by the outdoor fan. 
The fluid refrigerant of low temperature and high pressure liquefied by the 
outdoor heat exchanger 2 passes through the expansion valve 3 for being 
expanded to atomized refrigerant of low temperature and low pressure and 
is infused simultaneously to two indoor heat exchangers 4 and 8. 
Accordingly, the atomized refrigerant in the indoor heat exchangers 4 and 8 
reduced to low pressure and low temperature by the expansion valve 3 
passes through various pipes, is evaporated and gasified, and takes the 
heat from the air blown by the indoor fan to cool the indoor air. The 
cooled air is discharged indoors to thereby perform the cooling operation. 
The gaseous refrigerant of low pressure and low temperature cooled by the 
indoor heat exchangers 4 and 8 is in turn fed into the compressor 1, and 
as a result, circulates repeatedly through cooling loops which are formed 
by solid line arrows and dotted line arrows illustrated in FIG. 3. 
However, there is another problem in the air conditioner for performing the 
simultaneous coolings according to the cooling cycle thus described, in 
that no effective results can be accomplished in case heating of one room 
and cooling of another room should be performed, although there is an 
advantage in that various rooms can be simultaneously cooled by connecting 
various indoor units to one outdoor unit. 
Accordingly, the present invention is disclosed to solve the aforementioned 
problems and it is an object of the present invention to provide a control 
apparatus of an air conditioner and a method thereof for employing various 
indoor units connected to one outdoor unit (compressor) to or heat various 
room spaces either simultaneously or individually. 
SUMMARY OF THE INVENTION 
In accordance with one aspect of the present invention, there is provided a 
control apparatus of an air conditioner, the control apparatus comprising: 
operation manipulating means for inputting an operating condition covering 
simultaneous cooling and heating of a plurality of room spaces, 
simultaneous but separate heating and cooling of a plurality of room 
spaces, individual cooling and heating of a certain room space while other 
rooms remain uncontrolled; 
control means for controlling a plurality of indoor units with one outdoor 
unit according to the operating condition input by the operation 
manipulating means to thereby control the cooling and heating operations 
of a plurality of room spaces; 
compressor driving means for driving a compressor according to control of 
the control means to thereby perform simultaneous cooling and heating of a 
plurality of room spaces, simultaneous but separate heating and cooling of 
a plurality of room spaces and individual cooling and heating of a certain 
room space while other rooms remain uncontrolled; 
four way valve driving means for receiving a control signal output from the 
control means according to the operating condition input by the operation 
manipulating means to controllably drive a four way valve so that a 
passage of refrigerant circulating therein can be changed; and 
solenoid valve driving means for receiving the control signal output from 
the control means according to the operating condition input by the 
operation manipulating means to controllably drive a solenoid valve so 
that the passage of the refrigerant circulating therein can be opened and 
closed. 
In accordance with another aspect of the present invention, there is 
provide a control method of an air conditioner, the method comprising the 
steps of: 
inputting an established temperature and operating conditions covering 
simultaneous cooling and heating of a plurality of room spaces, 
simultaneous but separate heating and cooling of a plurality of room 
spaces, individual cooling and heating of a certain room space while other 
rooms remain uncontrolled; 
controlling the passage of the refrigerant circulating therein by 
controlling on and off operations of the solenoid valve and the four way 
valve according to the operating conditions input by the inputting step; 
driving a compressor by determining an operation frequency according to a 
difference between the established temperature and a room temperature 
input by the inputting step; and 
operating the air conditioner by performing simultaneous cooling and 
heating of a plurality of room spaces, simultaneous but separate heating 
and cooling of a plurality of room space, individual cooling and heating 
of a certain room space while other rooms remain uncontrolled, according 
to refrigerant passage controlled at the refrigerant passage control step 
when the compressor is driven at the compressor driving step.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION 
The preferred embodiment of the present invention will now be described in 
detail with reference to the accompanying drawings. 
Referring to FIG. 4, direct current DC electric power source means 10 
serves to receive an electrical source voltage of commercial alternating 
current AC electric power supplied from an alternating current power 
source terminal to convert the same to a predetermined direct current 
voltage necessary for operation of the air conditioner and output the 
same. 
Operation manipulating means 15 includes manual operation selecting keys 
(simultaneous cooling, simultaneous heating, separate but simultaneous 
cooling and heating, individual cooling, individual heating, defrost, 
artificial intelligence operation, air cleaning, operation booking, 
operation/stop and the like) and a plurality of manual functional keys for 
inputting a set-up temperature, time set-up, set-up wind intensity, set-up 
wind direction. 
Control means 20 is a microcomputer which serves to receive the DC voltage 
output from the DC power source means 10 to initialize the air conditioner 
and to control overall operations of the air conditioner according to the 
operating condition and operation/stop signal input by the operation 
manipulating means 15. 
Indoor temperature detecting means 25 serves to control the room 
temperature to thereby cause the same to become the temperature 
established by the user by way of the operation manipulating means 15, so 
that the air conditioner can be operated. The indoor temperature detecting 
means 25 also serves to detect a temperature Tr of room air sucked through 
a suction inlet (not shown) to thereby output the same to the control 
means 20. 
Four-way valve driving means 30 serves to receive a control signal of the 
control means 20 in order to cause the refrigerant to change the route or 
passage in which the refrigerant circulates, according to the operating 
conditions (heating or cooling) input by the operation manipulating means 
15, i.e., four-way valves 31, 32, 33 and 34 can be controllably driven to 
thereby be opened and closed. 
Solenoid valve driving means 40 serves to receive the control signal output 
from the control means 20 in order to open or close the passage in which 
the refrigerant circulates, according to the operating conditions (heating 
or cooling) input by the operation manipulating means 15, i.e., solenoid 
valves 41 through 50 can be controllably driven to be closed and opened. 
Furthermore, compressor driving means 60 serves to receive the control 
signal output from the control means 20 according to a difference between 
a temperature Ts established by the user by way of the operation 
manipulating means 15 and the room temperature Tr detected by the indoor 
temperature detecting means 25 to thereby controllably drive a compressor 
61. 
Outdoor fan motor driving means 70 serves to receive the control signal of 
the control means 20 according to the difference between the temperature 
Ts established by the user and the room temperature Ts detected by the 
indoor temperature detecting means 25, and to control the operation of an 
outdoor fan 71 to circulate the air heat-exchanged by an outdoor heat 
exchanger. 
Indoor fan motor driving means 80 serves to receive the control signal 
output from the control means 20 according to wind intensity selected by 
the user by way of the operation manipulating means 15 to control 
operation of an indoor fan 81 so that the air (hot air or cool air) 
heat-exchanged by an indoor heat exchanger can be blown into the room. 
Display means 90 serves to display the operating conditions established by 
the user by way of the operation manipulating means 15 according to the 
control of the control means 20 and at the same time, serves to display an 
operation state of the air conditioner as well. 
Referring to FIG. 5, a cooling cycle for performing the cooling and heating 
operations of the air conditioner thus constructed will now be described. 
As illustrated in FIG. 5, the four-way valves 31, 32, 33 and 34 are adapted 
to be opened and closed by the electric power in order to establish the 
passage in which the refrigerant circulates according to the control of 
the control means 20. 
The solenoid valves 41 through 50 are arranged to open or close the passage 
in which the refrigerant circulates according to the control of the 
control means 20 and are adapted to be opened and closed by the electric 
power in order to prevent the refrigerant from flowing backward. 
The compressor 61 serves to compress the infused refrigerant gas to gaseous 
state of high temperature and high pressure and discharge the same. The 
outdoor heat exchanger serves to heat-exchange the refrigerant by way of 
the air blown by the outdoor fan 71 to thereby cool the same, where one 
outdoor unit is provided with first and second outdoor heat exchangers 101 
and 103 respectively. 
The indoor heat exchanger is adapted to heat-exchange the refrigerant with 
the air blown by the indoor fan 81 to thereby cause the same to be cooled, 
where a first indoor unit and a second indoor unit are provided with first 
and second indoor heat exchangers 102 and 104 respectively. 
One-way valves 105 and 106 are adapted to prevent the fluid refrigerant of 
high pressure and high temperature liquefied at the outdoor heat 
exchangers 101 and 103 from passing through heating expansion valves 109 
and 110 during the cooling operation and to prevent the refrigerant 
liquefied at the indoor heat exchangers 102 and 104 from passing through 
the heating expansion valves 109 and 110 during the heating operation, so 
that the refrigerant can pass through in one direction only. 
Expansion valves 107 and 108 serve to eject rapidly the refrigerant through 
small orifices to thereby expand the same to evaporative pressure, so that 
the refrigerant can become atomized to a foggy state of high pressure and 
high temperature. 
Solenoid valves 49 and 50 are disposed at upper sides of the indoor heat 
exchangers 102 and 104. When room temperatures Tr of various rooms to be 
controlled are different one another, the valves 49, 50 serve to open or 
close the first and second indoor heat exchangers 102 and 104 according to 
the control of the control means 20, so that various room spaces can be 
controllably operated to a optimum. 
Now, the control apparatus of the air conditioner thus constructed and 
operational effect of method thereof will be described. 
FIGS. 5, 9A and 9B describe, by way of example, a cooling cycle and 
operation control procedure when two rooms are simultaneously cooled. 
First of all, when electricity is supplied to the air conditioner, DC 
electric power source means 10 serves to convert commercial AC power to a 
predetermined DC voltage necessary for driving the air conditioner, 
thereby supplying the same to respective driving circuits and control 
means 20. 
Accordingly, at step S1, the DC voltage output from the DC electric power 
source means 10 is received by the control means 20 to thereby initialize 
the air conditioner. 
At step S2, the operating conditions (simultaneous cooling, simultaneous 
heating, separate but simultaneous cooling and heating, individual 
cooling, individual heating and the like) selected by the user by way of 
the operation manipulating means 15 and the selected temperature Ts are 
input to the control means 20, and an operation/stop button is pressed. 
At this time, the display means 90 serves to display the operating 
conditions, and the selected temperature Ts and the like input by the 
operation manipulating means 15 according to the control of the control 
means 20. 
Successively, at step S3, the control means 20 determines whether the 
operation condition input by the operation manipulating means 15 is 
"simultaneous cooling operation", and if it is determined that the 
condition is not the "simultaneous cooling operation" (in case of no), the 
control means 20 maintains the air conditioner in operation stand-by 
state. 
As a result of the determination at step S3, if the operating condition 
input by the operation manipulating means 15 is "simultaneous cooling 
operation" (in case of yes), the control means 20 at step S4 serves to 
output a control signal for controlling the four-way valves 31, 32, 33 and 
34 and solenoid valves 41 through 50 to simultaneously cool the two room 
spaces. 
Accordingly, the four-way valve driving means 30 receives the control 
signal output from the control means 20 to thereby deactivate the four-way 
valves 31, 32, 33 and 34. 
At this time, the four-way valves 31 to 34 serve to allow the refrigerant 
to circulate in a direction depicted by solid lines during valve 
deactivation, and serve to let the refrigerant circulate in a direction 
depicted by dotted lines during activation. 
At step S5, the control means 20 outputs the control signal for controlling 
the solenoids 41 through 50 via the solenoid valve driving means 40. 
Subsequently, the solenoid valve driving means 40 receives the control 
signal output from the control means 20 to thereby deactivate the solenoid 
valves 41, 43, 45, 47, 49 and 50 and at the same time, to activate the 
solenoid valves 42, 44, 46 and 48. 
The solenoid valves 41 through 50 are open during the deactivation period 
and are closed during the activation period. 
At step S6, the control means 20 serves to generate a control signal for 
driving the indoor fan 81 via indoor fan motor driving means 80. 
The indoor fan motor driving means 80 serves to receive the control signal 
coming out of the control means 20 according to the wind intensity input 
by the operation manipulating means 75 to thereby control the indoor fan 
motor and to drive the indoor fan 81. 
When the indoor fan is activated, the indoor air starts to be infused into 
the air conditioner through an inlet (not shown), and at step S7, the 
temperature Tr of indoor air traveling through the inlet is detected by 
the indoor temperature detecting means 25, to thereby allow the same to be 
output to the control means 20. 
At this time, it is assumed that the room temperatures Tr of the two rooms 
detected by the indoor temperature detecting means 25 are identical. 
Successively, at step S8, a determination is made as to whether the common 
room temperature Tr detected by the indoor temperature detecting means 25 
is larger than the selected temperature Ts input by the operation 
manipulating means 15, and if it is determined that the indoor temperature 
Tr is not larger than the selected temperature Ts (in case of no), flow 
returns to step S7 because there is no need to cool the room, and the room 
temperature Tr is continuously detected. 
As a result of step S8, if it is determined that the room temperature Tr is 
larger than the selected temperature Ts (in case of yes), the rooms should 
be cooled, so that, at step S9, a determination is made as to whether a 
predetermined time (delay time for protecting the compressor: 
approximately 3 minutes) has lapsed after the indoor fan is activated at 
step S6, and if the predetermined time has not elapsed (in case of no), 
flow returns to step S6 and drives only the indoor fan 81 until the 
predetermined time lapses. 
As a result of the determination at step S9, if the predetermined time has 
lapsed (in case of yes), which means that there is no problem to the 
compressor 61 even it is driven because the consumed current is constant, 
the control means 20, at step S10, determines an operational frequency of 
the compressor 61 according to the difference between the room temperature 
Tr and the selected temperature Ts and outputs a control signal for 
driving the compressor 61 to compressor driving means 60. 
Accordingly, the compressor driving means 60 serves to drive the compressor 
61 according to the operational frequency determined by the control means 
20. 
When the compressor 61 is driven, the refrigerant gas is compressed to 
gaseous state of high temperature and high pressure and, according to the 
afore-mentioned activation and deactivation of the four-way valves 31, 32, 
33 and 34 and solenoid valves 41 through 50 by way of the control of the 
control means 20, is infused to the first and second outdoor heat 
exchangers 101 and 103 through the four-way valves 31, 32, 33 and 34. 
The first and second outdoor heat exchangers 101 and 103 serve to 
heat-exchange the gaseous refrigerant compressed to high temperature and 
high pressure with the air blown by the outdoor fan 71, to forcibly cool 
the refrigerant and to liquefy the same. 
The fluid refrigerant of low temperature and high pressure liquefied by the 
first and second outdoor heat exchangers 101 and 103 is reduced to 
atomized refrigerant of low temperature and low pressure through one-way 
valves 105 and 106 and through expansion valves 107 and 108, and is 
infused to the first and second indoor heat exchangers 102 and 104 through 
the solenoid valves 49 and 50. 
Accordingly, the first and second indoor heat exchangers 102 and 104 serve 
to take out the heat from the air blown by the indoor fan 81 when the 
atomized refrigerant reduced to low temperature and low pressure by the 
expansion valves 107 and 108 passes through a plurality of pipes to 
thereby cool the room air and discharge the cooled air indoors to perform 
the cooling operation. 
At this time, the gaseous refrigerant of low pressure and low temperature 
cooled by the first and second indoor heat exchangers 102 and 104 is 
infused again into the compressor 61 through the solenoid valves 41 
through 48 and is repeatedly circulated through two cooling cycles as 
illustrated by solid line arrows (.fwdarw.) and dotted line arrows () in 
FIG. 5. 
In other words, the refrigerant flows through a solid-arrow cooling cycle 
for one room where the cool air heat-exchanged by the first indoor heat 
exchanger 102 is discharged indoors, which cycle is formed by the 
compressor 61.fwdarw.four-way valves 31, 33 and 34.fwdarw.first outdoor 
heat exchanger 101.fwdarw.one-way valve 105.fwdarw.expansion valve 
107.fwdarw.solenoid valve 49.fwdarw.first indoor heat exchanger 
102.fwdarw.solenoid valve 41.fwdarw.four-way valve 34.fwdarw.solenoid 
valve 43.fwdarw.compressor 61, and as illustrated in FIG. 5 in solid line 
arrows (.fwdarw.) the refrigerant is circulated to thereby perform the 
indoor cooling operation. 
Furthermore, the refrigerant flows through a dotted-arrow cooling cycle for 
another room where the cool air heat-exchanged by the second indoor heat 
exchanger 104 is discharged indoors, which cycle is formed by the 
compressor 61.fwdarw.four-way valves 31 and 32.fwdarw.second outdoor heat 
exchanger 103.fwdarw.one-way valve 106.fwdarw.expansion valve 
108.fwdarw.solenoid valve 50.fwdarw.second indoor heat exchanger 
104.fwdarw.solenoid valve 45.fwdarw.four-way valve 31.fwdarw.solenoid 
valve 47.fwdarw.compressor 61, and the refrigerant is circulated along the 
dotted line arrows illustrated in FIG. 5 to thereby execute the indoor 
cooling operation. 
As noted above, the air conditioner is adapted to one outdoor unit 
(compressor) which is in turn connected to two indoor units, so that two 
room spaces can be simultaneously cooled according to the operating 
condition established by the user. 
At this time, at step S11, the room temperature Tr (assumed as the same for 
both rooms) which changes when the compressor 1 is being driven is 
detected by the indoor temperature detecting means 25 to allow the same to 
be output to the control means 20, and at step S12, it is determined 
whether the room temperature Tr detected by the indoor temperature 
detecting means 25 is the same as the selected temperature Ts input by the 
user by way of the operation manipulating means 15. 
As a result of the determination at step S12, if the room temperature Tr is 
not the same as the selected temperature Ts (in case of no), which means 
that the room has to be cooled continuously, flow returns to step S11. 
Meanwhile, as a result of the determination at step S12, if the room 
temperature Tr is the same as the selected temperature Ts (in case of 
yes), which means that the room cooling should be stopped, flow proceeds 
to step S13, where the control means 20 outputs a control signal for 
stopping a driving of the compressor 61 to compressor driving means 60. 
Accordingly, the compressor driving means 60 serves to stop the driving of 
the compressor 61 according to the control of the control means 20 to 
thereby stop the operation. 
In the above-mentioned description, an example has been disclosed to 
describe a case where the room temperatures Tr of two rooms are identical. 
However, in case of the two rooms having different room temperatures Tr 
(by way of example, 30 degrees celsius in a first indoor unit while 25 
degrees celsius in a second indoor unit), the operational frequency of the 
compressor 61 is determined based on the room temperature (30 degrees 
celsius) of the first indoor unit where the room temperature is higher and 
then the compressor 61 is driven. 
When the compressor 61 is driven, the second indoor unit which has first 
reached the selected temperature is stopped because the second indoor unit 
where the room temperature Tr is lower (25 degrees celsius) reaches the 
selected temperature Ts faster than the first indoor unit where the room 
temperature is higher (30 degrees celsius), and only the first indoor unit 
which has not reached the selected temperature Ts should then be 
cool-operated. 
Accordingly, the control means 20 serves to control the solenoid valves 49 
and 50 disposed at the first and second indoor heat exchangers 102 and 
104, so that the solenoid valve 50 of the second indoor heat exchanger 104 
at the second indoor unit which has first reached the selected temperature 
Ts is caused to be closed. 
The solenoid valve 49 of the first indoor heat exchanger 102 at the first 
indoor unit which has not reached the established temperature Ts, so that 
the passage where the refrigerant is circulated therein can remain open. 
Of course, in case the room temperatures are reversed (by way of example, 
25 degrees in celsius for the first indoor unit and 30 degrees celsius for 
the second indoor unit), the solenoid valve 49 at the first indoor unit 
where the selected temperature Ts is first reached is caused to be turned 
on to thereby close the passage, and the solenoid valve 50 at the second 
indoor unit where the selected temperature Ts is not reached remains 
deactivated, to thereby keep open the passage. 
Next, simultaneous heating of two room spaces will be described with 
reference to FIG. 6 and FIGS. 10A and 10B. 
FIG. 6 is a cooling cycle for illustrating a simultaneous heating operation 
of an air conditioner according to a second operating mode of the present 
invention, and FIGS. 10A and 10B are flow charts for illustrating 
operational procedures of simultaneous heating control of an air 
conditioner according to the present invention. 
First of all, when the power is supplied to the air conditioner, DC power 
source means 10 serves to convert the commercial AC voltage supplied from 
an AC power source terminal (not shown) to a predetermined DC voltage 
necessary for driving the air conditioner, thereby outputting the same to 
respective driving circuits and the control means 20. 
Accordingly, at step S21, the control means 20 serves to receive the DC 
voltage output from the DC power source means 10 to thereby initialize the 
air conditioner. At step S22, the operating conditions of the air 
conditioner desired by the user (simultaneous cooling, simultaneous 
heating, separate but simultaneous cooling and heating, individual 
cooling, individual heating and the like) and the selected temperature Ts 
are input to the control means 20 and the operation/stop button is 
pressed. 
At this time, the display means 90 serves to display the operating 
conditions input by the operation manipulating means 15 and the selected 
temperature Ts and the like according to the control of the control means 
20. 
Successively, at step S23, the control means 20 determines whether the 
operating conditions input by the operation manipulating means 15 is the 
"simultaneous heating operation", and if it is determined as not being 
"simultaneous heating operation", (in case of no), the air conditioner is 
maintained at the operation stand-by state. 
As a result of the determination at step S23, if the operating condition 
input by the operation manipulating means 15 is the I simultaneous heating 
operation", (in case of yes), which means that the four-way valves 31, 32, 
33 and 34 and the solenoid valves 41 through 50 should be controlled to 
simultaneously heat the two room spaces, the control means 20 at step S24 
outputs a control signal for controlling the four-way valves 31, 32, 33 
and 34 via the four-way valve driving means 30. 
Accordingly, the four-way valve driving means 30 receives the control 
signal output from the control means 20 to thereby deactivate the four-way 
valves 31 and 34 and at the same time, to activate the four-way valves 32 
and 33. 
At this time, the four-way valves 31, 32, 33 and 34 allow the refrigerant 
to be circulated in a direction depicted by solid lines, during 
deactivation, and allow the refrigerant to be circulated in a direction 
depicted by dotted lines when activated. 
Successively, at step S25, the control means 20 serves to generate a 
control signal for controlling the solenoid valves 41 through 50 to the 
solenoid valve driving means 
Therefore, the solenoid valve driving means 40 receives the control signal 
output from the control means 20 to thereby deactivated the solenoid 
valves 42, 44, 46, 48, 49 and 50 and at the same time, to activate the 
solenoid valves 41, 43, 45 and 47. 
At step S26, the control means 20 serves to generate a control signal for 
driving the indoor fan 81 via the indoor fan driving means 80. 
Accordingly, the indoor fan motor driving means 80 serves to receive the 
control signal output from the control means 20 according to the 
established wind intensity input by the operation manipulating means 15, 
thereby controlling the indoor fan motor and driving the indoor fan 81. 
When the indoor fan 81 is driven, the room air starts to be infused into 
the air conditioner through an inlet (not shown). 
At step S27, the temperature of the room air traveling through the inlet is 
detected by the indoor temperature detecting means 25, to thereby cause 
the same to be output to the control means 20. 
At this time, if it is assumed that the room temperatures Tr of the two 
rooms detected by the indoor temperature detecting means 25 are the same, 
a discrimination is made at step S28 as to whether the common room 
temperature Tr detected by the indoor temperature detecting means 25 is 
smaller than the selected temperature input by the operation manipulating 
means 15, and if the room temperature Tr is not smaller than the selected 
temperature Ts (in case of no), which means that there is no need to heat 
the room, flow returns to step S27 and keeps detecting the room 
temperature Tr. 
As a result of step S28, if it is determined that the room temperature Tr 
is smaller than the selected temperature Ts (in case of yes), which calls 
for heating in the room, a determination is made at step S29 as to whether 
a predetermined time (delayed time for protecting the compressor: 
approximately 3 minutes) has elapsed after the indoor fan 81 is driven at 
step S26. 
If the predetermined time has not lapsed (in case of no), flow returns to 
step S26 and drives the indoor fan 81 only until the predetermined time 
lapses. 
As a result of step S29, if the predetermined time has lapsed (in case of 
yes), which means that there is no problem to be incurred to the 
compressor 61 even if it is driven because the consumed current is 
constant, so that the control means 20 determines at step S30 the 
operating frequency of the compressor 61 according to the difference 
between the room temperature Tr and the selected temperature Ts, thereby 
causing a control signal for driving the compressor 61 to be fed to the 
compressor driving means 60. 
Accordingly, the compressor driving means 60 serves to drive the compressor 
61 according to the operating frequency determined by the control means 
20. 
When the compressor 61 is driven, the refrigerant gas is compressed by the 
compressor 61 to a gaseous state of high temperature and of high pressure 
according to on/off operation of the four-way valves 31, 32, 33 and 34 and 
the solenoid valves 41 through 50 by way of the control of the control 
means 20 to thereby be infused into the first and second indoor heat 
exchangers 102 and 104 through the four-way valves (31, 33), (31, 32) and 
the solenoid valves 42 and 46. 
The first and second indoor heat exchangers 102 and 104 serve to 
heat-exchange the gaseous refrigerant compressed to high temperature and 
high pressure by the first and second indoor heat exchangers 102 and 104 
by way of the air blown by the indoor fan 81, so that warm air generated 
by the cooling of the refrigerant of room temperature and of high pressure 
can be discharged indoors to thereby cause the heating operation to be 
executed. 
The fluid refrigerant of low temperature and high pressure liquefied by the 
first and second indoor heat exchangers 102 and 104 passes through the 
expansion valves 107 and 108 for being expanded to evaporative pressure, 
and passes through expansion valves 109 and 110 through the solenoid 
valves 49 and 50, to thereby be reduced to atomized refrigerant of low 
pressure and low temperature and is infused into the first and second 
outdoor heat exchangers 101 and 103. 
The first and second outdoor heat exchangers 101 and 103 serve to receive 
the atomized refrigerant reduced to low pressure and low temperature by 
way of the expansion valves 107 and 108 and expansion valves 109 and 110, 
to thereby heat-exchange the air blown by the outdoor fan 71 by way of 
latent heat of the refrigerant and to cool the same. 
The gaseous refrigerant of low pressure and low temperature cooled by the 
first and second outdoor heat exchangers 101 and 103 is in turn conducted 
into the compressor 61 through the four-way valves (34, 33) and (32), and 
through the solenoid valves 44 and 48, and flows in two heating cycles of 
repeated circulation as illustrated solid line arrows (.fwdarw.) and 
dotted line (.fwdarw.) in FIG. 6. 
In other words, the refrigerant flows through a solid-line heating cycle 
for one room where the warm air (warm wind) heat-exchanged by the first 
indoor heat exchanger 102 is discharged indoors, which cycle is formed by 
the compressor 61.fwdarw.four-way valve 31 and 33.fwdarw.solenoid valve 
42.fwdarw.first indoor heat exchanger 102.fwdarw.solenoid valve 
49.fwdarw.expansion valve 107 expansion valve for heating 109.fwdarw.first 
outdoor heat exchanger 101 four-way valves 34 and 33.fwdarw.solenoid valve 
44.fwdarw.compressor 61, so that the refrigerant can be circulated along 
the solid line arrows (.fwdarw.) in FIG. 6 to thereby perform the room 
heating. 
Furthermore, the refrigerant flows through a dotted line heating cycle for 
another room where the warm air (warm wind) heat-exchanged by the second 
indoor heat exchanger by the second indoor heat exchange 104 is discharged 
indoors, which cycle is formed by the compressor 61.fwdarw.four-way valves 
31 and 32.fwdarw.solenoid valve 46.fwdarw.second indoor heat exchanger 
104.fwdarw.solenoid valve 50.fwdarw.expansion valve 108 expansion valve 
for heating 110.fwdarw.second outdoor heat exchanger 103 four-way valve 
32.fwdarw.solenoid valve 48.fwdarw.compressor 61, so that the refrigerant 
can be circulated along the dotted line arrows in FIG. 6 to thereby 
perform the room heating. 
As is apparent from the above, the air conditioner having one outdoor unit 
(compressor) connected to two indoor units can heat two room spaces 
simultaneously according to the operating conditions established by the 
user. 
At this time, the room temperature Tr which changes when the compressor 61 
is driven is detected at step S31 by the indoor temperature detecting 
means 25, to allow the same to be output to the control means 20. 
A determination is made at step S32 as to whether the room temperature Tr 
detected by indoor temperature detecting means 25 is the same as the 
selected temperature Ts input by the user by way of the operation 
manipulating means 15. 
As a result of step S32, if the room temperature Tr is not the same as the 
selected temperature Ts (in case of no), which implies that the room 
should be continuously heated, flow returns to step S30. 
Meanwhile, as a result of the determination at step S32, if the room 
temperature Tr is the same as the selected temperature Ts (in case of 
yes), which represents that the room heating should be stopped, flow 
proceeds to step S33, where the control means 20 serves to output a 
control signal for stopping the drive of the compressor 61 to the 
compressor driving means 60. 
Accordingly, the compressor driving means 60 stops the driving of the 
compressor 61 according to the control of the control means 20 to thereby 
terminate the operation. 
Although the above-mentioned description has described, by way of example, 
a case where the room temperatures Tr of two rooms to be heated are the 
same, in case the room temperatures Tr of the two rooms are different (by 
way of example, 5 degrees celsius for the first indoor unit and 10 degrees 
celsius for the second indoor unit), the operating frequency of the 
compressor 61 is determined based on the room temperature (5 degrees 
celsius) at the first indoor unit where the room temperature Tr is lower, 
to thereby drive the compressor 61. 
When the compressor 61 is driven, the second indoor unit which has first 
arrived at the established temperature Ts stops the heating operation 
because the second indoor unit where the room temperature Tr is higher (10 
degrees celsius) reaches the selected temperature Ts faster than the first 
indoor unit where the room temperature Tr is lower (5 degrees celsius), so 
that only the first indoor unit which has not reached the selected 
temperature Ts should be operated for heating. 
Accordingly, the control means 20 serves to control the solenoid valves 49 
and 50 disposed at the first and second indoor heat exchangers 102 and 
104, so that the solenoid valve 50 of the second indoor heat exchanger 104 
at the second indoor unit which has first arrived at the selected 
temperature Ts is turned on, to thereby cut off the passage in which the 
refrigerant is circulated. 
The solenoid valve 49 arranged at the first indoor heat exchanger 102 which 
has not reached the selected temperature Ts is caused to remain 
deactivated, thereby keeping open the passage where the refrigerant is 
circulated. 
Of course, in case the room temperatures Tr are reversed (by way of 
example, 10 degrees celsius for the first indoor unit and 5 degrees 
celsius for the second indoor unit), the solenoid valve 49 at the first 
indoor unit which has first arrived at the selected temperature Ts is made 
to be operative, thereby cutting off the passage of the refrigerant 
circulation, and the solenoid valve 50 at the second indoor unit which has 
not reached the established temperature Ts remains deactivated, thereby 
keeping open the passage. 
Consequently, two separate room spaces having different room temperatures 
Tr can be controllably heated to an optimum state. 
Next, a description will be made as to a case where one room is heated 
while the other room is cooled. 
The operations of the step S8 or S28 and the step S12 or S32 described in 
the flow charts in FIGS. 9A and 9B and FIGS. 10A and 10B are identical, so 
that redundant descriptions thereof will be omitted, and only the 
refrigerant circulating process of the cooling cycle will be described 
which changes according to on/off operations of the four-way valves 31, 
32, 33 and 34 and the solenoid valves 41 through 50 by way of control of 
the control means 20. 
First of all, a case where the first room is cooled while the second room 
is heated will be described with reference to FIG. 7. 
FIG. 7 is a schematic diagram for illustrating simultaneous heating and 
cooling operations of an air conditioner according to a third operating 
mode of the present invention. 
When a heating operation of the second room and a cooling operation of the 
first room are selected by the user's manipulation of the operation 
manipulating means 15, the four-way valves 31, 33 and 34 and the solenoid 
valves 41, 43, 46, 48, 49 and 50 become deactivated while the four-way 
valve 32 and the solenoid valves 42, 44 and 45 become activated. 
In the cooling operation of the first room according to the on/off 
operations of the four-way valves 31, 32, 33 and 34 and the solenoid 
valves 41 through 50 by way of the control of the control means 20, the 
refrigerant compressed by the compressor 51 to gaseous state of high 
pressure and high temperature is introduced to the first outdoor heat 
exchanger 101 through the four-way valves 31, 33 and 34, and the first 
outdoor heat exchanger 101 heat exchanges the gaseous refrigerant with the 
air blown by the outdoor fan 71, so that the refrigerant is forcibly 
cooled and liquefied. 
The liquid refrigerant liquefied by the first outdoor heat exchanger 101 is 
reduced to atomized refrigerant of low pressure and low temperature when 
the same passes through the expansion valve 107 for being expanded to 
evaporative pressure via the one-way valve 105, and is infused into the 
first indoor heat exchanger 102 through the solenoid valve 49. 
Accordingly, the first indoor heat exchanger 102 removes heat from the air 
blown by the indoor fan 81 to thereafter be cooled when the atomized 
refrigerant reduced to low pressure and low temperature by the expansion 
valve 107 is evaporated and gasified via a plurality of pipes, where the 
cooled air (cool wind) is discharged indoors to thereby perform the 
cooling operation. 
At this time, the gaseous refrigerant of low pressure and low temperature 
cooled by the first indoor heat exchanger 102 is in turn fed into the 
compressor 61 through the solenoid valve 41, the four-way valve 34 and the 
solenoid valve 43, and is circulated in a repeated cooling cycle as 
illustrated by solid line arrows (.fwdarw.) in FIG. 7. 
In other words, the refrigerant in the cooling cycle, where the cool air 
(cool wind) heat-exchanged by the first indoor heat exchanger 102 is 
discharged indoors, flows through a cycling loop which is formed by the 
compressor 61.fwdarw.four-way valves 31, 33 and 34.fwdarw.first outdoor 
heat exchanger 101 one-way valve 105.fwdarw.expansion valve 
107.fwdarw.solenoid valve 49.fwdarw.first indoor heat exchanger 
102.fwdarw.solenoid valve 41.fwdarw.four-way valve 34.fwdarw.solenoid 
valve 43.fwdarw.compressor 61, to thereafter perform the cooling operation 
of the room. 
Furthermore, in the heating operation of the second indoor unit driven by 
the four-way valves 31, 32, 33 and 34 and the solenoid valves 41 through 
50 according to the control of the control means 20, the refrigerant 
compressed by the compressor 61 to gaseous state of high exchanger 104 is 
conducted through the four-way valves 31 and 32 and through the solenoid 
valve 46, and the second indoor heat exchanger 104 serves to heat-exchange 
the gaseous refrigerant compressed to high temperature and high pressure 
by way of the air blown by the indoor fan 81, so that the warm wind 
generated when the refrigerant of room temperature and high pressure is 
cooled is discharged indoors to thereby perform the heating operation. 
The fluid refrigerant of low temperature and high pressure liquefied by the 
second indoor heat exchanger 104 passes through the expansion valve 108 
for expanding the same to evaporative pressure and the expansion valve 110 
via the solenoid valve 50, to thereafter be reduced to atomized 
refrigerant of low temperature and low pressure and infused into the 
second outdoor heat exchanger 103. 
Accordingly, the second outdoor heat exchanger 103 serves to receive the 
atomized refrigerant reduced by the expansion valve 108 and the expansion 
valve 110 to low pressure and low temperature, and to heat-exchange the 
air blown by the outdoor fan 71 by way of the evaporative latent heat of 
the refrigerant, to cool the same. 
The gaseous refrigerant of low temperature and low pressure cooled by the 
second outdoor heat exchanger 103 is in turn fed into the compressor 61 
through the four-way valve 32 and the solenoid valve 48 and flows through 
a cooling cycle of repeated circulation as illustrated by dotted line 
arrows (.fwdarw.) in FIG. 7. 
In other words, the refrigerant in the cooling cycle, where warm wind 
heat-exchanged by the second indoor heat exchanger 104 is discharged 
indoors, flows through a circulation loop which is formed by the 
compressor 61.fwdarw.four-way valves 31 and 32.fwdarw.solenoid valve 
46.fwdarw.second indoor heat exchanger 104.fwdarw.solenoid valve 
50.fwdarw.expansion valve 108.fwdarw.expansion valve for heating 
110.fwdarw.second outdoor heat exchanger 103.fwdarw.four-way valve 
32.fwdarw.solenoid valve 48.fwdarw.compressor 61, thereby performing the 
heating of the room. 
Next, a case where the first indoor unit is heated while the second indoor 
unit is cooled will be described with reference to FIG. 8. 
FIG. 8 is a schematic diagram for illustrating heating and cooling 
operations of an air conditioner according to a fourth operating mode of 
the present invention. 
When the heating operation of the first indoor unit 102 and cooling 
operation of the second indoor unit 104 are selected by the user's 
manipulation of the operation manipulating means 15, the four-way valves 
42, 44, 45, 47, 49 and 50 become deactivated according to the control of 
the control means 20, and the four-way valve 33 and solenoid valves 41, 
43, 46 and 48 are activated. 
In the heating operation of the first indoor unit according to the on/off 
operations of the four-way valves 31, 32, 33 and 34 and the solenoid 
valves by way of the control of the control means 20, the refrigerant 
compressed by the compressor 61 to gaseous state of high pressure and high 
temperature is infused into the first indoor heat exchanger 102 via the 
four-way valves 31 and 33 and the solenoid valve 42, and the first indoor 
heat exchanger 102 serves to heat-exchange the gaseous refrigerant by way 
of the air blown by the indoor fan 81, so that the warm wind generated 
when the refrigerant of room temperature and high pressure is cooled is 
discharged indoors, to thereby perform the heating operation. 
The fluid refrigerant of low temperature and high pressure liquefied by the 
first indoor heat exchanger 102 passes through the expansion valves 107, 
109 via the solenoid valve 49, to thereby be reduced to atomized 
refrigerant of low temperature and low pressure and to be infused into the 
first outdoor heat exchanger 101. 
Accordingly, the first outdoor heat exchanger 101 serves to receive the 
atomized refrigerant, and heat-exchange the air blown by the outdoor fan 
71 by way of the evaporative latent heat of the refrigerant and cool the 
same. 
The gaseous refrigerant of low pressure and low temperature cooled by the 
first outdoor heat exchanger 101 is in turn infused into the compressor 61 
through the four-way valves 34 and 33 and the solenoid valve 44, and flows 
in a cooling cycle of repeated circulation as illustrated by solid line 
arrows in FIG. 8. 
In other words, the refrigerant in the cooling cycle, where the warm wind 
heat-exchanged by the first indoor heat exchanger 102 is discharged 
indoors, circulates in a loop which is formed by the compressor 
61.fwdarw.four-way valves 31 and 33.fwdarw.solenoid valve 42.fwdarw.first 
indoor heat exchanger 102.fwdarw.solenoid valve 49.fwdarw.expansion valve 
107 expansion valve for heating 109.fwdarw.first outdoor heat exchanger 
101 four-way valves 34 and 33.fwdarw.solenoid valve 44.fwdarw.compressor 
61, to thereby perform the heating of the room. 
In the cooling operation of the second indoor unit 104 according to on and 
off operations of the four-way valves 31, 32, 33 and 34 and the solenoid 
valves 41 through 50 by way of the control of the control means 20, the 
refrigerant compressed by the compressor 61 to gaseous state of high 
temperature and high pressure is infused into the second outdoor heat 
exchanger 103 through the four-way valves 31 and 32, and the second 
outdoor heat exchanger 103 serves to heat-exchange the gaseous refrigerant 
compressed to high temperature and high pressure by way of the air blown 
by the outdoor fan 71, forcibly cooling the refrigerant and liquefying the 
same. 
The liquid refrigerant of low temperature and high pressure liquefied by 
the second outdoor heat exchanger passes the expansion valve 108 for 
expanding the same to evaporative pressure via the one-way valve 106, to 
thereby be reduced to atomized refrigerant of low pressure and low 
temperature, and is infused to the second indoor heat exchanger 104 via 
the solenoid valve 50. 
Accordingly, the second indoor heat exchanger 104 serves to absorb the heat 
from the air blown by the indoor fan 81 and discharge the cooled air (cool 
wind) to the room and perform the cooling operation. 
At this time, the gaseous refrigerant of low temperature and low pressure 
cooled by the second indoor heat exchanger 104 is in turn conducted into 
the compressor 61 through the solenoid valve 45, four-way valve 31 and 
through the solenoid valve 47, so that the refrigerant flows in a cooling 
cycle of repeated circulation an illustrated by dotted line arrows in FIG. 
8. 
In other words, the refrigerant in the cooling cycle where the cool wind 
heat-exchanged by the second indoor heat exchanger 104 is discharged to 
the room, circulates in a loop which is formed by the compressor 
61.fwdarw.four-way valves 31 and 32.fwdarw.second outdoor heat exchanger 
103.fwdarw.one-way valve 106.fwdarw.expansion valve 108.fwdarw.solenoid 
valve 50.fwdarw.second indoor heat exchanger 104.fwdarw.solenoid valve 
45.fwdarw.four-way valve 31.fwdarw.solenoid valve 47.fwdarw.compressor 61, 
to thereby perform the cooling operation of the room. 
As apparent from the foregoing, the air condition thus described employing 
one outdoor unit (compressor) connected to two indoor units can cool and 
heat two room spaces simultaneously according to the operating conditions 
set up by the user. 
If would have been obvious to one of ordinary skill in the art to cut off 
the cooling cycle for a certain room of the simultaneous cooling or 
simultaneous heating rooms to thereby perform the individual cooling and 
individual heating. 
Although embodiments of the present invention have disclosed cases where 
the passage is controlled in order to have the refrigerant to circulate 
along the full line arrows when the four-way valves 31, 32, 33 and 34 are 
deactivated, while the passage is controlled in order to have the 
refrigerant to circulate along the dotted line arrows when the four-way 
valves are activated, the present invention is not intended to be so 
limited. 
In particular, it should be noted that the passage can be controlled so as 
to have the refrigerant to circulate along the dotted line arrows when the 
four-way valves 31, 32, 33 and 34 are deactivates while the passage can be 
controlled to have the refrigerant to circulate along the full line arrows 
when the four-way valves are activated. 
Furthermore, although the embodiment of the present invention has been 
described with reference to one example where the passage of the 
refrigerant circulation is opened when the solenoid valves 41 through 50 
are deactivated while the passage is closed when the solenoid valves are 
activated, the present invention is not intended to be so limited, and it 
should be apparent that the purpose and effect of the present invention 
can be also accomplished by change of the electric power sources of the 
solenoid valves 41 through 50 where the passage of the refrigerant 
circulation is cut off when the solenoid valves 41 through 50 are 
deactivated while the passage is opened when the solenoid valves are 
activated. 
Although the present invention has been disclosed with reference to the 
embodiment where one outdoor unit (compressor) is connected to two indoor 
units, to thereby perform simultaneous cooling, simultaneous heating and 
separate but simultaneous cooling and heating of two room spaces, the 
present invention and the drawings are not to be taken as limiting, and it 
should be noted that according to the present invention, one outdoor unit 
(compressor) can be connected to more than two indoor units, to thereby 
control a plurality of room spaces simultaneously, or to individually cool 
or heat respective room spaces. 
As is apparent from the above description, the control apparatus of an air 
conditioner and a method thereof according to the present invention can 
simultaneously cool and heat, and separately but simultaneously cool and 
heat a plurality of room spaces, employing one outdoor unit (compressor) 
connected with a plurality of indoor units, and at the same time, can 
individually cool or heat the plurality of room spaces. 
Having described specific preferred embodiment of the invention with 
reference to the accompanying drawings, it is to be understood that the 
invention is not limited to that precise embodiment, and that various 
changes and modifications may be effected therein by one skilled in the 
art without departing from the scope or spirit of the invention as defined 
in the appended claims.