WO2007097547A2

WO2007097547A2 - Air conditioning system and method of controlling the same

Info

Publication number: WO2007097547A2
Application number: PCT/KR2007/000844
Authority: WO
Inventors: Young-Koung Kim
Original assignee: Lg Electronics Inc.
Priority date: 2006-02-20
Filing date: 2007-02-16
Publication date: 2007-08-30
Also published as: WO2007097547A3; CN101668994B; KR101133621B1; KR20070083055A; CN101668994A

Abstract

The invention relates to an air conditioning system and a method of controlling the air conditioning system. The air conditioning system includes a controller (60) for setting a ventilation mode and a ventilation/air-cleaning device (10) operating based on the ventilation mode set by the controller (60). The ventilation mode of the ventilation/air-cleaning device (10) changes depending on a pollution level of indoor air detected by a pollution sensor (104). In the method, it is determined whether an air conditioner (70) operates in association with a ventilation/air-cleaning device (10). If so, a pollution level of indoor air is detected using a pollution sensor (104). Operations of the air conditioner (70) and the ventilation/air-cleaning device (10) is controlled according to the detected pollution level.

Description

AIR CONDITIONING SYSTEM AND METHOD OF CONTROLLING THE SAME

Technical Field

[1] The present invention relates to an air conditioning system and a method of controlling the air conditioning system, and more particularly, to an air conditioning system operating automatically in proper mode according to the concentration of carbon dioxide contained in air, and a method of controlling the air conditioning system. Background Art

[2] When a person breathes in a closed space, the concentration of carbon dioxide increases with time, and thus it is difficult for the person to breathe. Hence, an office where many persons stay or a car having a small indoor space should be periodically ventilated. For this purpose, a ventilation system can be used.

[3] A common ventilation system is installed on a floor or fixed to a ceiling to introduce outside air and discharge indoor air. The ventilation system can be usefully used for a place where airflow is poor or many persons stay.

[4] However, a ventilation system of the related art has only an air cleaning device or a ventilation device. Hence, when indoor temperature is largely different from outdoor temperature, the related art ventilation system cannot provide comfortable ventilation due to the large temperature difference.

[5] Furthermore, the air cleaning device and the ventilation device of the ventilation system cannot be operated in association with each other according to the pollution level and temperature of indoor air. Thus, an operation mode of the ventilation system should be manually selected. Therefore, the ventilation system of the related art cannot provide optimized air conditioning. Disclosure of Invention Technical Problem

[6] Accordingly, the present invention is directed to an air conditioning system and a method of controlling the air conditioning system that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.

[7] An object of the present invention is to provide an air conditioning system that automatically operates a ventilation/air-cleaning device in cleaning mode or ventilation mode according to the concentration of CO2 included in indoor air and operates the ventilation/air-cleaning device in association with an air conditioner for maintain the temperature of indoor air comfortably, and a method of controlling the air conditioning system.

Technical Solution

[8] To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, there is provided a

[9] According to another aspect of the present invention, there is provided an air conditioning system including: a controller for setting a ventilation mode; and a ventilation/air-cleaning device operating based on the ventilation mode set by the controller, wherein the ventilation mode of the ventilation/air-cleaning device changes depending on a pollution level of indoor air detected by a pollution sensor.

[10] According to a further another aspect of the present invention, there is provided a method of controlling an air conditioning system, the method including: determining whether an air conditioner operates in association with a ventilation/air-cleaning device; if so, detecting a pollution level of indoor air using a pollution sensor; and controlling operations of the air conditioner and the ventilation/air-cleaning device according to the detected pollution level. Advantageous Effects

[11] According to the present invention, the concentration of CO2 in indoor air and the variation rate of the CO2 concentration are detected to compare the variation rate of the CO2 concentration with a predetermined reference value. If the CO2 concentration variation rate is equal to or higher than a predetermined reference value, a ventilation/ air-cleaning device and an air conditioner are both controlled by automatically changing the operation mode of the ventilation/air-cleaning device in association with the operation of the air conditioner. Therefore, the present invention increases the commercial and economic values of a product since comfortable air conditioning can be provided in an economical method. Brief Description of the Drawings

[12] The accompanying drawings provide a further understanding of the present invention.

[13] FlG. 1 is a perspective view illustrating a ventilation/air-cleaning device of an air conditioning system according to the present invention.

[14] FlG. 2 is an exploded perspective view of the ventilation/air-cleaning device of

FIG. 1.

[15] FlG. 3 is a perspective view illustrating airflow of the ventilation/air-cleaning device in ventilation mode.

[16] FlG. 4 is a perspective view illustrating airflow of the ventilation/air-cleaning device in air-cleaning mode.

[17] FlG. 5 is a perspective view illustrating an air conditioning system according to the present invention.

[18] FlG. 6 is a sectional view illustrating airflow of the air conditioning system of FlG.

5.

[19] FlG. 7 is a schematic block diagram illustrating airflow of an air conditioning system according to the present invention.

[20] FlG. 8 is a flowchart for explaining a method of controlling an air conditioning system according to the present invention. Best Mode for Carrying Out the Invention

[21] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to accompanying drawings.

[22] FlG. 1 is a perspective view illustrating a ventilation/air-cleaning device 10 of an air conditioning system according to the present invention, and FlG. 2 is an exploded perspective view of the ventilation/air-cleaning device 10.

[23] Referring to FlGs. 1 and 2, the ventilation/air-cleaning device 10 includes: a front cover 11 having an air suction opening 111 (refer to FlG. 4) at a center portion; a cover guide 12 receiving the front cover 11 ; a grill 14 having a discharge grill 141 at front and side portions and coupled with the cover guide 12 by sliding the cover guide 12 to the discharge grill 14; a filter 13 disposed under the grill 14 to remove odor and foreign substances such as dust from air sucked into the ventilation/air-cleaning device 10; a control box 19 coupled to a lower edge of the discharge grill 14; a control panel 21 detachably coupled to a lower portion of the cover guide 12; and a screening member 23 that selectively opens and closes the discharge grill 141 of the discharge grill 14.

[24] In detail, the control box 19 includes a main PCB substrate for controlling the operation of the ventilation/air-cleaning device 10. For this, a microcomputer is mounted on the main PCB as a control unit. A display PCB substrate is mounted on a rear surface of the control panel 21 to display an operational status of the ventilation/ air-cleaning device 10.

[25] When the ventilation/air-cleaning device 10 is fixed to a comer where a ceiling and a wall meet, a side of the discharge grill 141 facing the wall is screened by the screening member 23. In this case, air is discharged from the ventilation/air-cleaning device 10 through the other side and the front of the air discharge grill 141.

[26] The ventilation/air-cleaning device 10 further includes: a fan 15 disposed above the filter 13 to suck indoor or outdoor air into the ventilation/air-cleaning device 10; a shroud 145 detachably coupled to a lower portion of the grill 14 to guide indoor or outdoor air sucked by the fan 15; a fan motor 20 driving the fan 15; and a rear panel 16 on which the fan motor 20 is mounted. A discharge duct and an air-supply duct are connected to a side portion of the rear panel 16. [27] The ventilation/air-cleaning device 10 further includes: a base panel 22 coupled to an upper portion of the rear panel 16 as a reinforcement member; an installation case 17 coupled to the side portion of the rear panel 16 where the discharge and air-supply ducts are connected so as to facilitate coupling of the discharge and air-supply ducts to the rear panel 16; and installation bars 18 detachably coupled to a top portion of the rear panel 16 for easy installation of the rear panel 16 to a wall or ceiling.

[28] In detail, the installation case 17 includes a suction hole 173 allowing an inflow of outdoor air and a discharge hole 172 allowing an outflow of indoor air. The rear panel 16 includes a suction hole 163 and a discharge hole 162 that correspond to the suction and discharge holes 173 and 172, respectively. Therefore, indoor and outdoor air can flow into and out of the ventilation/air-cleaning device 10 through the suction and discharge holes 173 and 172 and the suction and discharge holes 163 and 162.

[29] It will now be described how air flows through the ventilation/air-cleaning device

10 in air-cleaning or ventilation mode with reference to the accompanying drawings.

[30] FlG. 3 is a perspective view for explaining how air flows through the ventilation/ air-cleaning device 10 in ventilation mode.

[31] Referring to FlG. 3, the ventilation/air-cleaning device 10 is mounted on a ceiling, and a duct member 30 formed through a wall is connected to the suction and discharge holes 173 and 172 of the installation case 17. Alternatively, a duct member formed through the ceiling can be connected to the installation case 17. In this case, the installation case 17 may have a different shape. Detailed description of the alternative case will be omitted.

[32] The duct member 30 includes an air-supply duct 31 allowing outdoor air to flow into the ventilation/air-cleaning device 10 and a discharge duct 32 allowing indoor air to be discharged to an outdoor area.

[33] In more detail, when a ventilation mode is selected, outdoor air is introduced into the ventilation/air-cleaning device 10 from the air-supply duct 31 through the suction hole 173 of the installation case 17 and the suction hole 163 of the rear panel 16. In the ventilation/air-cleaning device 10, the fan 15 causes the air to flow upward through the filter 13 disposed under the grill 14 to a space formed between the grill 14 and the air discharge grill 141. While the air flows through the filter 13, foreign substances such as dust are removed from the air. Then, the air is horizontally distributed and discharged from the ventilation/air-cleaning device 10 to an indoor area through the discharge grill 141 of the discharge grill 14.

[34] Meanwhile, in the ventilation mode, indoor air is introduced into the ventilation/ air-cleaning device 10 through an air- vent grill 141 formed at a lateral corner of the discharge grill 14. The air- vent grill 148 is bent along an edge of the discharge hole 162 of the rear panel 16. The indoor air introduced through the air-vent grill 148 is directed to the discharge holes 162 and 172, and then is discharged to an outside area through the discharge duct 32.

[35] FlG. 4 is a perspective view for explaining how air flows through the ventilation/ air-cleaning device 10 in air-cleaning mode.

[36] Referring to FlG. 4, when an air-cleaning mode is selected for the ventilation/ air-cleaning device 10, air does not flow through the air-supply and discharge ducts 31 and 32 since a heat recovery ventilator (described later) connected to the air-supply and discharge ducts 31 and 32 does not operate in the air-cleaning mode. This will be described in more detail.

[37] In the air-cleaning mode, indoor air is introduced into the ventilation/air-cleaning device 10 through the air suction opening 111 of the front cover 11. In the ventilation/ air-cleaning device 10, the air is cleaned by the filter 13 and then is discharged back to an indoor area through the discharge grill 141 of the grill 14.

[38] In more detail, in the air-cleaning mode, the fan 15 is driven to introduce indoor air through the air suction opening 111. Then, the introduced air is cleaned by passing the air through the filter 13 and is directed to the fan 15 through an orifice 143 (refer to FlG. 2). At the fan 15, the air is horizontally distributed. The air guide 144 guides the horizontally distributed air to the discharge grill 141 to discharge the air back to the indoor area through the discharge grill 141.

[39] FlG. 5 is a perspective view illustrating an air conditioning system according to the present invention, and FlG. 6 is a sectional view for explaining how air flows through the air conditioning system of FlG. 5.

[40] Referring to FlGs. 5 and 6, the air conditioning system of the present invention includes the ventilation/air-cleaning device 10, a heat recovery ventilator 50 connected to the ventilation/air-cleaning device 10 through the duct member 30, and a controller 60 connected to the ventilation/air-cleaning device 10 by a wired/wireless communication scheme for selecting a ventilation or air-cleaning mode.

[41] In detail, the duct member 30 includes the air-supply duct 31 and the discharge duct

32. One end of the duct member 30 is connected to the suction and discharge holes 173 and 172 of the ventilation/air-cleaning device 10, and the other end of the duct member 30 is connected to the heat recovery ventilator 50. A suction connection tube 33 and a discharge connection tube 34 are interposed between the duct member 30 and the heat recovery ventilator 50 to firmly connect the duct member 30 to the heat recovery ventilator 50.

[42] The heat recovery ventilator 50 is installed for heat exchange between outdoor air introduced into an indoor area and indoor air discharged to an outdoor area, such that the temperature of the indoor area can be prevented from being suddenly increased or decreased. For example, when the temperature of the indoor area is equal to or higher than that of the outdoor area, heat is transferred from indoor air discharged to the outdo or area to outdoor air introduced into the indoor area. Thus, the temperature of the outdoor air introduced into the indoor area can approach the temperature of the indoor area, and the temperature of the indoor area can be prevented from being largely changed by the outdoor air introduced from the outdoor area into the indoor area.

[43] In detail, the heat recovery ventilator 50 includes a discharge inlet 52, an air-supply outlet 53 spaced apart from the discharge inlet 52, a discharge outlet 54 formed at a location opposite to the discharge inlet 52, an air-supply inlet 55 formed at a location opposite to the air-supply outlet 53, and a heat exchanger 51.

[44] In more detail, the heat exchanger 51 is installed in the heat recovery ventilator 50 for heat exchange between outdoor air and indoor air without mixing the outdoor and indoor air.

[45] The heat recovery ventilator 50 further includes a discharge fan 57 installed in a tube connected between the discharge inlet 52 and the discharge outlet 54, and an air- supply fan 56 installed in a tube connected between the air-supply inlet 55 and the air- supply outlet 53.

[46] In detail, the discharge inlet 52 is formed on the same side as the air-supply outlet

53, and the discharge outlet 54 is formed on the same side as the air-supply inlet 55. The positions of the discharge inlet 52 and the air-supply outlet 53 can vary according to the type of the heat recovery ventilator 50. For the same reason, the positions of the discharge outlet 54 and the air-supply inlet 55 can vary.

[47] In more detail, the discharge inlet 52 is connected to the discharge connection tube

34 to receive indoor air discharged from the ventilation/air-cleaning device 10. The air- supply outlet 53 is connected to the air-supply connection tube 33 to supply outdoor air to the ventilation/air-cleaning device 10.

[48] A user manipulates operation buttons of the controller 60 to operate the ventilation/ air-cleaning device 10 and/or the heat recovery ventilator 50 individually or in an interlocking manner.

[49] In other words, when a user selects a ventilation mode, the ventilation/air-cleaning device 10 and the heat recovery ventilator 50 are operated together for ventilation. On the other hand, when a user selects an air-cleaning mode, only the ventilation/ air-cleaning device 10 is operated for circulating and cleaning indoor air.

[50] The ventilation/air-cleaning device 10 further includes a CO2 sensor or volatile organic compound (VOC) sensor.

[51] In detail, the CO2 sensor measures the pollution level of indoor area by detecting the amount of CO2 included in indoor air. The VOC sensor is used to determine the amount of harmful substances included in indoor air by detecting the amount of VOCs included in indoor air. Here, the term "VOC" or "VOCs" are used to denote all kinds of organic compounds that can exist in liquid or solid phase at room temperature and pressure or in gas phase in the atmosphere. When a large amount of VOCs is included in air, human bodies can suffer from respiratory diseases, allergic skin diseases, or headache. Furthermore, a gas sensor can be installed in the ventilation/air-cleaning device 10 for detecting harmful gases other than VOCs. Alternatively, the gas sensor can be attached to a wall and connected to a control unit of the ventilation/air-cleaning device 10 by a wired communication scheme. The pollution level of indoor air can be measured using the above-described sensors, and the ventilation/air-cleaning device 10 can be automatically operated in ventilation and/or air-cleaning mode according to the measured pollution level.

[52] It will now be described how air flows through the air conditioning system.

[53] When a ventilation mode is selected for the air conditioning system by a user or automatically, the fan 15 of the ventilation/air-cleaning device 10 is driven, and the air- supply fan 56 and the discharge fan 57 of the heat recovery ventilator 50 are driven.

[54] Outdoor air is introduced into the heat recovery ventilator 50 by the operation of the air-supply fan 56, and indoor air is introduced into the heat recovery ventilator 50 by the operation of the discharge fan 57. The outdoor air exchanges heat with the indoor air in the heat exchanger 51, and then the outdoor air is supplied to the ventilation/ air-cleaning device 10 through the air-supply duct 31. In the ventilation/air-cleaning device 10, the outdoor air passes through the filter 13 and then is discharged to an indoor area through the discharge grill 141 of the grill 14.

[55] FIG. 7 is a schematic block diagram illustrating an air conditioning system according to an embodiment of the present invention.

[56] Referring to FIG. 7, the air conditioning system of the current embodiment includes a controller 60, a ventilation/air-cleaning device 10, a heat recovery ventilator 50, and an air conditioner 70. The controller 60 is used to select a desired ventilation mode for the air conditioning system. The ventilation/air-cleaning device 10 is operated in the selected ventilation mode. The ventilation/air-cleaning device 10 measures the amount of CO2 included in indoor air to change the current operation mode of the air conditioning system according to the measured amount of CO2. The heat recovery ventilator 50 operates its fan motor according to the change of the operation mode. The air conditioner 70 can be operated in association with the ventilation/air-cleaning device 10.

[57] In detail, the controller 60 includes an input unit 61 for receiving a mode selection command and a display unit 62 for displaying the mode selection command.

[58] Here, the ventilation/air-cleaning device 10 can be operated manually or automatically according to a command input through the input unit 61. Furthermore, other basic setting commands can be input through the input unit 61. The display unit 62 displays information about a command input from the input unit 61 to inform a user of the command. That is, the display unit 62 displays information about the operational status of the ventilation/air-cleaning device 10.

[59] The ventilation/air-cleaning device 10 includes a signal receiving unit 102 for receiving a mode selection command from the controller 60, a detecting unit 103 detecting the amount of CO2 contained in air, and a control unit 101 for controlling a mode change of the ventilation/air-cleaning device 10 using the mode selection command and the amount of CO2 included in air.

[60] In detail, the signal receiving unit 102 receives a mode selection command and transmits the mode selection command to the control unit 101. Here, the signal receiving unit 102 receives the mode selection command from the controller 60 by a wired or wireless communication scheme.

[61] The detecting unit 103 includes a CO2 sensor 104 for detecting the concentration of

CO2 included in indoor air and a timer 105 for checking the time the CO2 sensor 104 detects the concentration of CO2. The CO2 concentration measured by the CO2 sensor 104 and the measurement time checked by the timer 105 are sent to the control unit 101.

[62] The CO2 sensor 104 detects only the amount of CO2 included in indoor air and transmits an electric signal corresponding to the detected amount of CO2 to the detecting unit 103. When the CO2 senor 104 operates, the timer 105 transmits time information to the detecting unit 103.

[63] The control unit 101 calculates the concentration of CO2 and a variation in the concentration of CO2 using the electric signal transmitted from the CO2 sensor 104. The control unit 101 can calculate a variation rate in CO2 concentration using a CO2 concentration variation measured for a predetermined time and Equation 1 below.

[64] [Equation 1]

[65]

CO₂ concentration variation rate =(ACO₂/Tl + ACO ₂/T2)/2

[66] where ΔCO2 denotes CO2 concentration variation, Tl denotes a first measurement time period, and T2 denotes a second measurement time period.

[67] Here, the control unit 101 can calculate the CO2 concentration variation rate for first and second measurement time periods Tl and T2.

[68] For example, the control unit 101 controls the detecting unit 103 to detect the concentration of CO2. Then, the detecting unit 103 detects the concentration of CO2 using the CO2 sensor 104. Here, the timer 105 measures start and end time points of the CO2 concentration measurement operation of the CO2 sensor.

[69] Then, the measured CO2 concentration and time information are transmitted from the detecting unit 103 to the control unit 101. The control unit 101 divides the time period during which the CO2 concentration is measured into first and second measurement time periods Tl and T2 and calculates CO2 concentration variation rates for the first and second time periods Tl and T2.

[70] In detail, the control unit 101 determines the first and second time periods Tl and

T2 in proportional to the total measurement time. Then, the control unit 101 calculates a first variation rate of CO2 concentration by dividing the variation of the CO2 concentration for the first time period Tl by the first time period Tl and a second variation rate of CO2 concentration by dividing the variation of the CO2 concentration for the second time period T2 by the second time period T2. After that, the control unit 101 calculates a mean variation rate of CO2 concentration by dividing the sum of the first and second variation rates by two.

[71] Then, the control unit 101 compares the mean variation rate of CO2 concentration with a first reference value. If the mean variation rate of CO2 concentration is equal to or higher than the first reference value, the control unit 101 switches the ventilation/ air-cleaning device 10 into forced ventilation mode. Here, the first reference value for the CO2 concentration variation rate may be 100 PPM/minute. However, the first reference value can be set to a different value.

[72] If the mean variation rate of CO2 concentration is smaller than the first reference value, the control unit 101 compares the mean variation rate of CO2 concentration with a second reference value. If the mean variation rate of CO2 concentration is equal to or higher than the second reference value, the control unit 101 switches the ventilation/ air-cleaning device 10 into heat processing mode in which the air conditioner 70 interlocked with the ventilation/air-cleaning device 10 is stopped and only the venti lation/air-cleaning device 10 is operated.

[73] Here, the second reference value for the CO2 concentration variation rate can be

1000 PPM/min. However, the second reference value can be set to a different value.

[74] As explained above, the control unit 101 can control the operations of the air conditioner 70 and the ventilation/air-cleaning device 10 according to measured CO2 concentration and the variation rate of the CO2 concentration regardless of the original operation modes of the air conditioner 70 and the ventilation/air-cleaning device 10. The heat recovery ventilator 50 operates in the same manner as described above. Thus, description of the operation of the heat recovery ventilator 50 will be omitted.

[75] FlG. 8 is a flowchart for explaining a method of controlling an air conditioning system according to the present invention.

[76] Referring to FlG. 8, in operation SlOO, it is determined whether the control unit 101 of the ventilation/air-cleaning device 10 controls the air conditioner 70 to be operated in association with the ventilation/air-cleaning device 10. [77] If one of the air conditioner 70 and the ventilation/air-cleaning device 10 does not operate, the control unit 101 controls the air conditioner 70 and the ventilation/ air-cleaning device 10 to operate in set modes, respectively. That is, the set modes are not automatically changed. Furthermore, the control unit 101 controls the timer 105 to operate.

[78] If the air conditioner 70 and the ventilation/air-cleaning device 10 are operated in association with each other, the operation of an indoor unit of the air conditioner 70 is checked in operation S200.

[79] The control unit 101 calculates CO2 concentration variation rate of indoor air and compares the calculated rate with a fist reference value in operation S300.

[80] Here, the control unit 101 controls the CO2 sensor 104 and the timer 105 to measure CO2 concentration variation of indoor air when the indoor unit of the air conditioner 70 operates. That is, the CO2 sensor 104 measures CO2 concentration variation of indoor air and the timer 105 measures a time period during which the CO2 sensor 104 measures the CO2 concentration variation. Information about the measured CO2 concentration variation and the measurement time is sent to the control unit 101. Then, the control unit 101 calculates CO2 concentration variation rate using the received information and Equation 1.

[81] Then, the control unit 101 compares the calculated CO2 concentration variation rate with the first reference value. If the calculated CO2 concentration variation rate is equal to or higher than the first reference value, the control unit 101 controls the air conditioner 70 and the ventilation/air-cleaning device 10 to be operated in forced ventilation mode. Furthermore, the control unit 101 controls the timer 105 to operate.

[82] If the calculated CO2 concentration variation rate is smaller than the first reference value, the control unit 101 compares the calculated CO2 concentration variation rate with a second reference value in operation S400.

[83] Here, if the calculated CO2 concentration variation rate is equal to or higher than the second reference value, the control unit 101 controls the air conditioner 70 and the ventilation/air-cleaning device 10 to be operated in heat processing mode.

[84] That is, the control unit 101 stops the operation of the air conditioner 70 and operates the ventilation/air-cleaning device 10 in the heat processing mode. Furthermore, the control unit 101 controls the timer 105 to operate.

[85] If the calculated CO2 concentration variation rate is smaller that than the second reference value, the air conditioner 70 and the ventilation/air-cleaning device 10 are operated in set ventilation mode, and the timer 105 is operated in operation S500.

[86] Here, when the calculated CO2 concentration variation rate is smaller than the second reference value, the control unit 101 controls the air conditioner 70 and the ventilation/air-cleaning device 10 to operate according to a set mode. [87] While the present invention has been described and illustrated herein with reference to the preferred embodiments thereof, it will be apparent to those skilled in the art that various modifications and variations can be made therein without departing from the spirit and scope of the invention. Thus, it is intended that the present invention covers the modifications and variations of this invention that come within the scope of the appended claims and their equivalents. Industrial Applicability

[88] The present invention provides an air conditioning system automatically operating in a desired ventilation mode according to the CO2 concentration of indoor air, and a method of controlling the air conditioning system. Therefore, the industrial applicability of the present invention is very high since the present invention can be applied to various industrial fields for comfort and convenient air conditioning.

[89]

Claims

[1] An air conditioning system comprising: a controller for setting a ventilation mode; and a ventilation/air-cleaning device operating based on the ventilation mode set by the controller, wherein the ventilation mode of the ventilation/air-cleaning device changes depending on a pollution level of indoor air detected by a pollution sensor.

[2] The air conditioning system according to claim 1, further comprising: a heat recovery ventilator of which fan motor is selectively operated based on the change of the ventilation mode of the ventilation/air-cleaning device; and an air conditioner capable of operating in association with the ventilation/ air-cleaning device.

[3] The air conditioning system according to claim 2, wherein the controller comprises: an input unit receiving a mode selection command for setting the ventilation mode; and a display unit for displaying the mode selection command.

[4] The air conditioning system according to claim 3, wherein the ventilation/ air-cleaning device comprises: a signal receiving unit for receiving the mode selection command from the controller; a detecting unit including the pollution sensor; and a control unit receiving the mode selection command from the signal receiving unit and the pollution level of indoor air from the detecting unit so as to change the ventilation mode of the ventilation/air-cleaning device based on the received mode selection command and the pollution level of indoor air, wherein the pollution sensor is a CO2 sensor detecting a concentration of CO2.

[5] The air conditioning system according to claim 4, wherein the detecting unit further includes a timer for measuring an operation time of the CO2 sensor.

[6] The air conditioning system according to claim 4, wherein the control unit controls operation modes of the air conditioner and the ventilation/air-cleaning device when the control unit changes the ventilation mode of the ventilation/ air-cleaning device based on CO2 concentration of indoor air.

[7] The air conditioning system according to claim 4, wherein the air conditioner and the ventilation/air-cleaning device, the control unit controls the air conditioner and the ventilation/air-cleaning device to be individually operated in set modes.

[8] The air conditioning system according to claim 4, wherein the control unit receives information about a CO2 concentration variation of indoor air and measurement time of the CO2 concentration variation and calculates a CO2 concentration variation rate using equation below: [Equation 1]

CO₂ concentration variation rate=(ACO₂/Tl +ACO₂/T2)/2 where ΔCO2 denotes a CO2 concentration variation, Tl denotes a first measurement time period, and T2 denotes a second measurement time period.

[9] The air conditioning system according to claim 8, wherein when the CO2 concentration variation rate is equal to or higher than a first reference value, the control unit switches the ventilation/air-cleaning device into a forced ventilation mode so as to forcibly operate the ventilation/air-cleaning device.

[10] The air conditioning system according to claim 9, wherein when the CO2 concentration variation rate is smaller than a first reference value, the control unit compares the CO2 concentration with a second reference value, wherein when the CO2 concentration is equal to or higher than the second reference value, the control unit stops the air conditioner and operates the ventilation/air-cleaning device.

[11] The air conditioning system according to claim 10, wherein when the CO2 concentration is smaller than the second reference value, the control unit operates the air conditioner and stops the ventilation/air-cleaning device.

[12] A method of controlling an air conditioning system, the method comprising: determining whether an air conditioner operates in association with a ventilation/ air-cleaning device; if so, detecting a pollution level of indoor air using a pollution sensor; and controlling operations of the air conditioner and the ventilation/air-cleaning device according to the detected pollution level.

[13] The method according to claim 12, further comprising operating the air conditioner and the ventilation/air-cleaning device in set modes if the air conditioner does not operate in association with the ventilation/air-cleaning device.

[14] The method according to claim 12, wherein the pollution sensor is a CO2 sensor detecting a concentration of CO2, the method further comprising: calculating a CO2 concentration variation rate using a CO2 concentration variation measured for a predetermined time period; comparing the CO2 concentration variation rate with a first reference value; and if the CO2 concentration variation rate is equal to or higher than the first reference value, operating the ventilation/air-cleaning device in a forced ventilation mode.

[15] The method according to claim 14, wherein if the CO2 concentration variation rate is smaller than the first reference value, the method further comprising: comparing the CO2 concentration with a second reference value; and if the CO2 concentration variation rate is smaller than the second reference value, operating the ventilation/air-cleaning device and the air conditioner in set modes, respectively.

[16] The method of claim 15, wherein the first reference value is 100 PPM/minute, and the second reference value is 1000 PPM.

[17] The method of claim 15 , further comprising : if the CO2 concentration is equal to or higher than the second reference value, stopping the air conditioner and operating the ventilation/air-cleaning device in a set mode.