EP1342961A1

EP1342961A1 - Method of controlling heating operation in an air conditioner

Info

Publication number: EP1342961A1
Application number: EP02255268A
Authority: EP
Inventors: Ki Seob Lee; Kwan Ho Yeom
Original assignee: LG Electronics Inc
Current assignee: LG Electronics Inc
Priority date: 2002-03-05
Filing date: 2002-07-29
Publication date: 2003-09-10
Anticipated expiration: 2022-07-29
Also published as: JP2003254584A; CN1442640A; KR20030072063A; DE60218627D1; KR100474892B1; JP3732809B2; EP1342961B1; DE60218627T2; CN1228581C

Abstract

Disclosed is a method of controlling a heating operation in an air conditioner enabling rapid supply of heating air to cope with the demanded temperature at the early stage of operation. An air conditioner including a compressor, a first heat exchanger, a second heat exchanger, a refrigerant, a first blow fan at a side of the first heat exchanger, a second blow fan, and a wind-direction control member, includes a power heating mode supplying a heating air by varying a blow quantity of the refrigerant, an airflow, and the wind direction in accordance with an operation time so as to raise room temperature quickly and clear a room temperature difference fast and a normal heating mode supplying the heating air with a uniform airflow and a uniform wind direction until a user-requested temperature is attained.

Description

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to an air conditioner, and more particularly, to a method of controlling a heating operation in an air conditioner.

Discussion of the Related Art

Generally, an air conditioner is an appliance installed in a room of a store, office, home, and the like so as to cool or heat room air. Such an air conditioner includes a cooling cycle system constructed with a compressor, first and second heat exchangers, and an expansion valve, whereby the room is cooled or heated by the consecutive evaporation and condensation of a refrigerant circulating in a cooling cycle.
Although all the components of an air conditioner may be installed in a single case, air conditioners usually include an indoor unit having the first heat exchanger and an outdoor unit having the second heat exchanger for pleasant room condition. In this case, heating or cooling air is generated from the first heat exchanger in accordance with a flow direction of the refrigerant.
Such a process is explained schematically as follows. First, for room heating, a refrigerant gas compressed at high temperature and pressure is sent to the first heat exchanger, and then exchanges heat with room air through the first heat exchanger so as to be condensed. The temperature of the room air, having passed the first heat exchanger, increases highly so as to be blown to the room. During such a process, the room air of high temperature is blown in a user-demanded direction by a wind-direction control member so as to heat the room. Subsequently, a refrigerant liquid condensed by the first heat exchanger passes the expansion valve to be decompressed to a pressure for easy evaporation so as to be sent to the second heat exchanger. The refrigerant liquid then exchanges heat with outdoor air through the second heat exchanger so as to evaporate. In this case, the temperature of the outdoor air having passed the second heat exchanger is reduced, whereby the outdoor air is blown outside the room.
Meanwhile, for room cooling, the refrigerant circulates in a direction opposite to that mentioned in the foregoing explanation. Hence, condensation of the refrigerant occurs in the second heat exchanger, while evaporation of the refrigerant does in the first heat exchanger. In this case, the room air is reduced in temperature so as to cool the room.
The above-operating air conditioner operates uniformly a blow fan circulating room air forcibly, a compressor, a wind-direction control member, and the like until its operation ends unless a user manipulates something additional. Hence, the air conditioner has the following problems or disadvantages.
First, as the blow fan and compressor operates uniformly from start to end of operation, it takes a quite a long time until a temperature of an entire room reaches a demanded degree. It causes a user, who fails to avoid being exposed to a chilly air for the time taken to reach the demanded temperature degree, inconvenience.
Second, as a heating air is blown in a fixed direction unless a user manipulates something additional from start to end of operation, it takes quite a long time to heat the room space evenly. A wind-direction control member generally has blow angles such as upper, middle-upper, middle, middle-lower, and lower angles. Without a user's manipulation, the wind-direction control member has the middle blow angle. Accordingly, the heating air is naturally blown to a middle part in the room, for which a considerable temperature difference occurs between upper and lower spaces of the room for a while. Namely, the heating air blown to the middle part of the room with a small density ascends naturally, while a cold air in the upper part of the room having the relatively low density descends. Hence, the room space for heating operation is heated in order of upper, middle, and lower parts. Yet, the user substantially stands on a floor of the room, thereby being exposed to the heating air insufficiently at the beginning of the heating operation.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a method of controlling a heating operation in an air conditioner that addresses one or more problems due to limitations and disadvantages of the related art.
It would be desirable to provide a method of controlling a heating operation in an air conditioner enabling to reduce a time taken to reach a user-requested temperature on heating operation.
It would also be desirable to provide a method of controlling a heating operation of an air conditioner enabling to overcome a temperature difference in a room space on heating operation.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, in an air conditioner including a compressor, a first heat exchanger discharging heat, a second heat exchanger absorbing the heat, a refrigerant circulating between the first and second heat exchangers, a first blow fan at a side of the first heat exchanger, a second blow fan at a side of the second heat exchanger, and a wind-direction control member adjusting a wind direction of a blow air, a method of controlling a heating operation in the air conditioner according to the present invention includes a power heating mode supplying a heating air by varying a blow quantity of the refrigerant, an airflow, and the wind direction in accordance with an operation time so as to raise a room temperature fast and clear a room temperature difference fast and a normal heating mode supplying the heating air with a uniform airflow and a uniform wind direction until a user-demanding temperature is attained.
Preferably, the power heating mode includes a step (a) of a rapid operation step of operating the compressor with a maximum operation frequency for a first setup time so as to raise the room temperature abruptly and a step (b) of a slow operation step, after the step (a), of operating the compressor with a variable operation frequency varying in accordance with the room temperature for a second setup time.
Preferably, the power heating mode includes a step (a) of a rapid operation step of operating the compressor with a maximum operation frequency for a first setup time so as to raise the room temperature abruptly, a step (b) of, after the step (a), comparing a room air temperature to a setup temperature, a step (c) of a first slow operation step of operating the compressor with a uniform operation frequency smaller than the maximum operation frequency for a second setup time so as to clear the room temperature difference if the room air temperature is higher than the setup temperature, and a step (d) of a second slow operation step of operating the compressor with a variable operation frequency varying in accordance with the room temperature for a second setup time so as to clear the room temperature difference if the room air temperature is lower than the setup temperature.
Accordingly, the present invention enables to reduce a time taken for a room temperature to reach a demanded degree by the rapid operation step as well as settle the temperature difference by the slow operation step.
It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:

FIG. 1A illustrates a diagram of components of an air conditioner according to the present invention;
FIG. 1B illustrates a bird's-eye view of an indoor unit in an air conditioner according to the present invention;
FIG. 2 illustrates a flowchart of a method of controlling a heating operation in an air conditioner according to a first embodiment of the present invention;
FIG. 3A and FIG. 3B illustrate tables for optimal operation frequencies of a compressor in a method of controlling a heating operation in an air conditioner according to the present invention; and
FIG. 4A and FIG. 4B illustrate a flowchart of a method of controlling a heating operation in an air conditioner according to a second embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
FIG. 1A illustrates a diagram of components of an air conditioner embodying the present invention.
Referring to FIG. 1A, an air conditioner embodying the present invention includes a compressor 1 compressing a refrigerant at high temperature and pressure, a first heat exchanger 2 condensing the compressed refrigerant, an expansion valve 3 expanding the condensed refrigerant adiabatically, and a second heat exchanger 4 evaporating the adiabatically expanded refrigerant isobarically. In this case, the first and second heat exchangers 2 and 4 enable to carry out functions opposite to each other in accordance with a flow direction of the refrigerant.
An operation speed of the compressor 1 varies in accordance with a frequency(hereinafter called operation frequency) of a voltage applied thereto, whereby a blow quantity of the refrigerant varies. Namely, the blow quantity of the refrigerant increases in proportion to the operation frequency for the compressor 1.
A first blow fan 2a is installed at one side of the first heat exchanger 2 so as to help condensation of the refrigerant by circulating an air forcibly. And, a second blow fan 4a is installed at one side of the second heat exchanger 4 so as to help evaporation of the refrigerant by circulating an air forcibly. In this case, the first and second blow fans 2a and 4a are operated so as to provide one of strong, medium, and weak winds in accordance with a blow quantity of air.
The above-constructed air conditioner includes an indoor unit having the first heat exchanger 2 and an outdoor unit having the second heat exchanger 4 and compressor 1.
FIG. 1B illustrates a bird's-eye view of an indoor unit in an air conditioner embodying the present invention.
Referring to FIG. 1B, the indoor unit includes a case 10 having an intake port 10 at a lower part and a blow outlet 10b at an upper part and the first heat exchanger and blow fan (2 and 2a in FIG. 1A) installed in the case 10. In this case, a wind-direction control member 20 adjusting a wind direction of a blow air is installed at the blow outlet 10b. The wind-direction control member 20 adjusts the wind directions of the blow air to five steps such as 'upward', 'middle-upward', 'middle', 'middle-downward', and 'downward'.
Meanwhile, a display part 30 informing a user of an operation status of an appliance is installed at one front side of the case 10. A plurality of buttons inducing a manipulation of the user are installed at the display part 30. The buttons include a button enabling to select a power heating mode or a normal heating mode for the heating operation. In this case, a control part controlling an entire operation of the appliance is installed at a back face of the display part 30. The control part controls an airflow and a location of the wind-direction control member 29 as well as an applied voltage of the compressor.
In this case, the power heating mode means an operation status that supplies a heating air by varying a blow quantity of the refrigerant, the airflow, and the wind direction in accordance with an operation time in order to overcome the temperature difference in the room as well as increase a temperature of the room. Such a power heating mode can be applied to an initial stage of the heating operation effectively, of which detailed explanation will be described later.
The normal heating mode means an operation status that the heating air is supplied with the constant airflow and wind direction until a user-demanding temperature is attained. Namely, at the normal heating mode, the wind-direction control member 20 is adjusted to the middle direction as well as the first blow fan 2a is operated with the medium wind.
A method of controlling a heating operation of an air conditioner, embodying the present invention, is explained in detail as follows.
FIG. 2 illustrates a flowchart of a method of controlling a heating operation of an air conditioner according to a first embodiment of the present invention.
Referring to FIG. 2, the control part judges whether a user-inputting operation status is the power or normal heating mode (S1). In this case, the user inputs the operation status through manipulation of buttons of the display part 30 or a remote controller.
If it is judged that the normal heating mode is inputted, the control part operates the wind-direction control member 20 and first blow fan 2a with the previously established airflow and wind direction until the room temperature reaches the user-demanding degree (S10).
If it is judged that the power heating mode is inputted, the control part checks the operation time (S2) and judges whether the operation time reaches a first setup time (S3). In this case, the control part carries out the rapid operation step of raising the temperature abruptly before the operation time reaches the first setup time (S20).
For this, the rapid operation step S20 includes the sub-steps of operating the compressor 1 at a maximum operation frequency so as to make a maximum blow quantity of the refrigerant( S21), adjusting the wind-direction control member 20 downward so as to concentrate the heating air generated through the first heat exchanger 2 on a room floor (S22), and operating the first blow fan 2a with the strong wind so as to make the blow quantity of the heating air become maximum (S23). In this case, the second blow fan 4a installed at the outdoor unit is preferably operated with the strong wind as well (S24). This is for the improvements of an efficiency of the compressor operated with the maximum operation frequency and a heat exchange rate in the first heat exchanger 2.
Subsequently, when the operation time reaches the first setup time, the control part carries out a slow operation step so as to clear the room temperature difference (S30). Thereafter, the control part judges whether a second setup time is reached or not (S4) as well as carries out the slow operation step S30.
For this, the slow operation step (S30) includes the sub-steps of operating the compressor 1 with a variable operation frequency depending on a room temperature (S31), adjusting the wind-direction control member 20 downward so as to concentrate the heating air on a floor of the room (S32), and operating the first blow fan 2 with the medium wind (S33). It is a mater of course that the second blow fan 4a is preferably operated with the weak wind in order to improve the efficiency of the compressor 1 and the heat exchange rate in the first heat exchanger 2 (S34).
In the slow operation step S30, the operation frequency of the compressor 1 is determined by a difference between a compressor-stop temperature Ts set up in accordance with a user-demanding degree and a temperature Td of the room air which is being sucked in, where the compressor-stop temperature Ts means a degree when the compressor 1 stops operating after the room temperature rises to some degree. The compressor-stop temperature Ts is resulted by adding 3~4 °C to the user-demanding temperature. In this case, in order to operate the compressor 1 optimally, the compressor 1 preferably has various steps of operation frequencies according to the temperature difference Ts-Td, and more preferably, at least a maximum operation frequency, a minimum operation frequency, and a rated operation frequency between the maximum and minimum operation frequencies.
FIG. 3A and FIG. 3B illustrate tables for optimal operation frequencies of a compressor in a method of controlling a heating operation in an air conditioner according to the present invention.
Referring to FIG. 3A, in the slow operation step, the compressor 1 is operated with the minimum operation frequency if Ts-Td is 0.0~0.99 °C, the rated operation frequency if Ts-Td is 1.0~2.49 °C, or the maximum operation frequency if Ts-Td is above 2.5 °C. Namely, a big value of 'Ts-Td' indicates that the difference between the room and user-demanding temperatures is big. In order to clear the room temperature difference quickly, the compressor 1 should be operated with the operation frequency proportional to the 'Ts-Td'.
Referring to FIG. 3B, it is seen that the operation frequency of the compressor 1 is more sub-divided than that in FIG. 3A. In this case, it is able to operate the compressor 1 more optimally.
First and second operation frequencies exist between the minimum operation frequency and rated operation frequency, and a third operation frequency lies between the rated and maximum operation frequencies. In this case, the second operation frequency is greater than the first and smaller than the third operation frequency.
In the slow operation step S30, the compressor 1 is operated with the first operation frequency between the minimum operation frequency and rated operation frequency if Ts-Td is 0.5~0.99 °C, the second operation frequency between the minimum operation frequency and the rated operation frequency if Ts-Td is 1.0~1.49 °C, or the third operation frequency between the rated operation frequency and the maximum operation frequency if Ts-Td is 2.0~2.49 °C.
Thereafter, the control part ends the power heating mode if the operation time reaches the second setup time, and is automatically switched to the normal heating mode so as to keep on heating the room (S10).
The first embodiment of the present invention, so to speak, controls an operation speed of the compressor 1 in accordance with the time in the rapid operation step S20 or the time and room temperature in the slow operation step S30. This works on raising the room temperature up to the demanded temperature rapidly as well as clearing the room temperature difference effectively.
FIG. 4A and FIG. 4B illustrate a flowchart of a method of controlling a heating operation of an air conditioner according to a second embodiment of the present invention.
Referring to FIG. 4A and FIG. 4B, the control part judges whether a user-inputting operation status is the power or normal heating mode (S1).
If it is judged that the normal heating mode is inputted, the control part operates the wind-direction control member 20 and first blow fan 2a with the previously established airflow and wind direction until the room temperature reaches the user-demanding degree (S10).
If it is judged that the power heating mode is inputted, the control part checks the operation time(S2) and judges whether the operation time reaches a first setup time (S3). In this case, the control part carries out the rapid operation step of raising the temperature abruptly before the operation time reaches the first setup time (S20).
The rapid operation step S20 includes the sub-steps of operating the compressor 1 with a maximum operation frequency (S21), adjusting the wind-direction control member 20 downward, and operating the first blow fan 2a with the strong wind (S23). In this case, the second blow fan 4a installed at the outdoor unit is preferably operated with the strong wind as well (S24). The rapid operation step S20 is the same of the first embodiment of the present invention.
Thereafter, when the operation time reaches the first setup time, the control part compares a setup temperature to a temperature of the room air sucked in for heat exchange (S5) . In this case, the setup temperature is lower than the user-demanding temperature so as to be a reference for controlling the compressor 1, the wind-direction control member 20, and the like differently to overcome the room temperature difference.
If the temperature of the sucked-in air is higher than the setup temperature, the control part carries out a first slow operation step operating the compressor 1 with a uniform operation frequency smaller than the maximum operation frequency so as to clear the room temperature difference (S40).
The first slow operation step (Ss0) includes the sub-steps of operating the compressor 1 with an operation frequency between the minimum operation frequency and the rated operation frequency (S41), adjusting the wind-direction control member 20 to the middle-downward direction (S42), and operating the first blow fan 2 with the medium wind (S43). In this case, the compressor can be operated with the first or second operation frequency in FIG. 3B.
In this case, the second blow fan 4 is preferably operated with the medium wind in order to improve the efficiency of the compressor 1 and the heat exchange rate in the first heat exchanger 2 (S44).
With the result of the comparison, if the temperature of the sucked-in air is lower than the setup temperature, the control part carries out a second slow operation step operating the compressor 1 for a second setup time with an operation frequency varying in accordance with the room temperature so as to clear the room temperature difference (S60).
The second slow operation step S60 includes the sub-steps of operating the compressor 1 with a variable operation frequency depending on the room temperature(S61), adjusting the wind-direction control member 20 to the middle-downward direction (S62), and operating the first blow fan 2 with the medium wind (S63). It is a mater of course that the second blow fan 4 is preferably operated with the weak wind in order to improve the efficiency of the compressor 1 and the heat exchange rate in the first heat exchanger 2 (S64).
In the second slow operation step S60, the operation frequency of the compressor 1, as is the same case of the foregoing described first embodiment of the present invention, is determined by a difference between a compressor-stop temperature Ts and a temperature Td of the room air. In this case, in order to operate the compressor 1 optimally, the compressor 1 preferably has various steps of operation frequencies according to the temperature difference Ts-Td, and more preferably, at least a maximum operation frequency, a minimum operation frequency, and a rated operation frequency between the maximum and minimum operation frequencies.
Namely, in the second slow operation step S60, the compressor 1 is operated with the minimum operation frequency if Ts-Td is 0.0~0.99 °C, the rated operation frequency if Ts-Td is 1.0~2.49 °C, or the maximum operation frequency if Ts-Td is above 2.5 °C, which is well shown in FIG. 3A.
Additionally, it is able to operate the compressor 1 with the more sub-divided operation frequencies. Namely, the compressor 1 is operated with a first operation frequency between the minimum operation frequency and the rated operation frequency if Ts-Td is 0.5~0.99 °C, a second operation frequency between the minimum operation frequency and the rated operation frequency if Ts-Td is 1.0~1.49 °C, or a third operation frequency between the rated operation frequency and the maximum operation frequency if Ts-Td is 2.0~2.49 °C, which is well shown in FIG. 3B.
Thereafter, the control part ends the power heating mode if the operation time reaches the second setup time, and is automatically switched to the normal heating mode so as to keep on heating the room (S10).
Briefly, in the slow operation step according to the second embodiment of the present invention, the compressor is operated with a constant operation frequency according to the room temperature abruptly raised through the rapid operation step or the operation frequency varying in accordance with the room temperature, thereby enabling to clear the room temperature difference fast.
Accordingly, the present invention enables to reduce the time taken to reach the demanded temperature from the initiation of the heating operation as well as clear the room temperature difference fast. Therefore, the user enables to be fast supplied with the heating air coping with the demanded temperature at the early stage of the operation.
It will be apparent to those skilled in the art than various modifications and variations can be made in the present invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims.

Claims

A method of controlling a heating operation in an air conditioner including a compressor, a first heat exchanger discharging heat, a second heat exchanger absorbing the heat, a refrigerant circulating between the first and second heat exchangers, a first blow fan at a side of the first heat exchanger, a second blow fan at a side of the second heat exchanger, and a wind-direction control member adjusting a wind direction of a blow air, the method comprising:
a power heating mode supplying a heating air by varying a blow quantity of the refrigerant, an airflow, and the wind direction in accordance with an operation time so as to raise a room temperature fast and clear a room temperature difference fast; and

a normal heating mode supplying the heating air with a uniform airflow and a uniform wind direction until a user-demanding temperature is attained.
The method of claim 1, the power heating mode comprising:
a step (a) of a rapid operation step of operating the compressor with a maximum operation frequency for a first setup time so as to raise the room temperature abruptly; and

a step (b) of a slow operation step, after the step (a), of operating the compressor with a variable operation frequency varying in accordance with the room temperature for a second setup time.
The method of claim 2, the step (a) comprising:
a sub-step (a1) of operating the compressor with the maximum operation frequency;

a sub-step (a2) of, if the wind-direction control member is adjusted to one of upward, middle-upward, middle, middle-downward, and downward directions in accordance with a blown direction of the heating air, adjusting the wind-direction control member to the downward direction so as to concentrate the heating air on a room floor; and

a sub-step (a3) of, when the first blow fan is operated with a strong, medium, or weak wind strength in accordance with a blown quantity of the heating air, operating the first blow fan with the strong wind strength so as to provide a maximum blown quantity of the heating air.
The method of claim 3, the step (a) further comprising a sub-step (a4) of, when the second blow fan is operated with a strong, medium, or weak wind strength in accordance with a blown quantity of an outdoor air, operating the second blow fan with the strong wind strength.
The method of claim 2, the step (b) comprising:
a sub-step (b1) of operating the compressor with variable operation frequency determined by the room temperature;

a sub-step (b2) of, if the wind-direction control member is adjusted to one of upward, middle-upward, middle, middle-downward, and downward directions in accordance with a blown direction of the heating air, adjusting the wind-direction control member to the downward direction so as to concentrate the heating air on a room floor; and

a sub-step (b3) of, when the first blow fan is operated with a strong, medium, or weak wind strength in accordance with a blown quantity of the heating air, operating the first blow fan with the medium wind strength.
The method of claim 5, the step (b) further comprising a sub-step (b4) of, when the second blow fan is operated with a strong, medium, or weak wind strength in accordance with a blown quantity of an outdoor air, operating the second blow fan with the weak wind strength.
The method of claim 5, wherein the compressor is operated with at least three operation frequencies determined by a difference between a compressor-stop temperature Ts set up in accordance with the user-demanding temperature and a temperature Td of a room air which is sucked in.
The method of claim 7, the sub-step (b1) comprising:
a further sub-step (b11) of operating the compressor with a minimum operation frequency if the difference between the Ts and Td is 0.0~0.99 °C;

a further sub-step (b12) of operating the compressor with a rated operation frequency if the difference between the Ts and Td is 1.0~2.49 °C; and

a further sub-step (b13) of operating the compressor with a the maximum operation frequency if the difference between the Ts and Td is greater than 2.5 °C.
The method of claim 8, the further sub-step (b11) comprising a step of operating the compressor with the operation frequency between the minimum operation frequency and the rated operation frequency if the difference between the Ts and Td is 0.5~0.99 °C
The method of claim 8, the further sub-step (b12) comprising the steps of:
operating the compressor with the operation frequency between the minimum operation frequency and the rated operation frequency if the difference between the Ts and Td is 1.0~1.49 °C; and

operating the compressor with the operation frequency between the rated operation frequency and the maximum operation frequency if the difference between the Ts and Td is 2.0~2.49 °C.
The method of claim 1, wherein the power and normal heating modes are carried out sequentially.
The method of claim 1, the power heating mode comprising:
a step (a) of a rapid operation step of operating the compressor with a maximum operation frequency for a first setup time so as to raise the room temperature abruptly;

a step (b) of, after the step (a), comparing a room air temperature to a setup temperature;

a step (c) of a first slow operation step of operating the compressor with a uniform operation frequency smaller than the maximum operation frequency for a second setup time so as to clear the room temperature difference if the room air temperature is higher than the setup temperature; and

a step (d) of a second slow operation step of operating the compressor with a variable operation frequency varying in accordance with the room temperature for a second setup time so as to clear the room temperature difference if the room air temperature is lower than the setup temperature.
The method of claim 12, the step (a) comprising:
a sub-step (a1) of operating the compressor with the maximum operation frequency;

a sub-step (a2) of, if the wind-direction control member is adjusted to one of upward, middle-upward, middle, middle-downward, and downward directions in accordance with a blown direction of the heating air, adjusting the wind-direction control member to the downward direction so as to concentrate the heating air on a room floor; and

a sub-step (a3) of, when the first blow fan is operated with a strong, medium, or weak wind strength in accordance with a blown quantity of the heating air, operating the first blow fan with the strong wind strength so as to provide a maximum blown quantity of the heating air.
The method of claim 13, the step (a) further comprising a sub-step (a4) of, when the second blow fan is operated with a strong, medium, or weak wind strength in accordance with a blown quantity of an outdoor air, operating the second blow fan with the strong wind strength.
The method of claim 12, the step (c) comprising:
a sub-step (c1) of operating the compressor with an operation frequency between a minimum operation frequency and a rated operation frequency;

a sub-step (c2) of, if the wind-direction control member is adjusted to one of upward, middle-upward, middle, middle-downward, and downward directions in accordance with a blown direction of the heating air, adjusting the wind-direction control member to the middle-downward direction; and

a sub-step (c3) of, when the first blow fan is operated with a strong, medium, or weak wind strength in accordance with a blown quantity of the heating air, operating the first blow fan with the medium wind strength.
The method of claim 15, the step (c) further comprising a sub-step (c4) of, when the second blow fan is operated with a strong, medium, or weak wind strength in accordance with a blown quantity of an outdoor air, operating the second blow fan with the weak wind strength.
The method of claim 12, the step (d) comprising:
a sub-step (d1) of operating the compressor with the variable operation frequency determined by the room temperature;

a sub-step (d2) of, if the wind-direction control member is adjusted to one of upward, middle-upward, middle, middle-downward, and downward directions in accordance with a blown direction of the heating air, adjusting the wind-direction control member to the middle-downward direction so as to concentrate the heating air on a middle part of the room; and

a sub-step (d3) of, when the first blow fan is operated with a strong, medium, or weak wind strength in accordance with a blown quantity of the heating air, operating the first blow fan with the medium wind strength.
The method of claim 17, the step (d) further comprising a sub-step (d4) of, when the second blow fan is operated with a strong, medium, or weak wind strength in accordance with a blown quantity of an outdoor air, operating the second blow fan with the weak wind strength.
The method of claim 17, wherein the compressor is operated with at least three operation frequencies determined by a difference between a compressor-stop temperature Ts set up in accordance with the user-demanding temperature and a temperature Td of a room air which is sucked in.
The method of claim 19, the sub-step (d1) comprising:
a further sub-step (d11) of operating the compressor with a minimum operation frequency if the difference between the Ts and Td is 0.0~ 0.99 °C;

a further sub-step (d12) of operating the compressor with a rated operation frequency if the difference between the Ts and Td is 1.0~ 2.49 °C; and

a further sub-step (d13) of operating the compressor with a the maximum operation frequency if the difference between the Ts and Td is greater than 2.5 °C.
The method of claim 20, the further sub-step (d11) comprising a step of operating the compressor with the operation frequency between the minimum operation frequency and the rated operation frequency if the difference between the Ts and Td is 0.5~0.99 °C
The method of claim 20, the further sub-step (d12) comprising the steps of:
operating the compressor with the operation frequency between the minimum operation frequency and the rated operation frequency if the difference between the Ts and Td is 1.0~1.49 °C; and

operating the compressor with the operation frequency between the rated operation frequency and the maximum operation frequency if the difference between the Ts and Td is 2.0~2.49 °C.
An air conditioner adapted to carry out the method steps of any preceding claim.