Air conditioners

Abstract

To provide an air conditioner that can restrain an increase in room temperature by accurately controlling the room temperature at the time of drying operation for drying an indoor heat exchanger.SOLUTION: An air conditioner (10) executes a drying operation for drying a surface of an indoor heat exchanger (32). A control unit (40) starts the drying operation from a heating operation, detects a room temperature (Tr3) by a room temperature sensor (41) during the drying operation, and switches between the heating operation and an air blowing operation when the detected room temperature (Tr3) reaches a predetermined temperature (Tc).SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an air conditioner equipped with a cleaning operation function for cleaning the surface of an indoor heat exchanger. [Background technology]

[0002] When an air conditioner is used for a long period of time, dust accumulates on the indoor heat exchanger. For this reason, some air conditioners are equipped with a cleaning function that cleans the surface of the indoor heat exchanger on which dust has accumulated. A conventional technique related to an air conditioner equipped with such a cleaning function is disclosed in Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-300030 A Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, after the indoor heat exchanger is cleaned by condensing the condensation, a drying operation is performed to dry the indoor heat exchanger. Specifically, the drying operation is a heating operation based on a set temperature that is set to a high temperature to promote drying.

[0005] If high-temperature heating operation is performed uniformly, it is expected that the room temperature will be higher than the room temperature that people feel comfortable in. Furthermore, in the case of high-temperature heating operation, the room temperature after the drying operation is too high, so that the user who enters the room feels uncomfortable and power consumption is high.

[0006] An object of the present invention is to provide an air conditioner that can suppress an increase in room temperature by accurately controlling the room temperature during drying operation to dry an indoor heat exchanger. [Means for solving the problem]

[0007] In claim 1, a refrigerant circuit in which a refrigerant circulates and flows, a compressor provided in the refrigerant circuit and capable of compressing a refrigerant; and an expansion valve provided in the refrigerant circuit and configured to reduce a pressure of the refrigerant; a four-way valve provided in the refrigerant circuit for switching a flow direction of the refrigerant; an indoor heat exchanger provided in the refrigerant circuit for exchanging heat between the refrigerant and indoor air; An indoor fan that takes in air from the room and blows air into the room; A room temperature sensor for detecting a room temperature; a control unit that controls the compressor, the expansion valve, the four-way switching valve, and the indoor fan to execute a heating operation for heating the room, a blowing operation for blowing air into the room by the indoor fan without performing heat exchange by the indoor heat exchanger, and a cleaning cooling operation for cleaning the surface of the indoor heat exchanger by causing condensation on the surface of the indoor heat exchanger, The control unit controls the compressor, the expansion valve, and the indoor fan to perform a drying operation to dry a surface of the indoor heat exchanger after performing the cleaning cooling operation, An air conditioner is provided in which the control unit starts the drying operation from the heating operation, detects the room temperature using the room temperature sensor during the drying operation, and switches between the heating operation and the fan operation when the detected room temperature reaches a preset temperature.

[0008] As described in claim 2, preferably, before the start of the cleaning cooling operation, the temperature is detected by the room temperature sensor or an outside air temperature sensor that detects the outside air temperature, When the detected temperature is equal to or lower than a first reference temperature, the start temperature of the heating operation, which is set when starting the drying operation, is set to a first start temperature; When the detected temperature is equal to or higher than a second reference temperature that is higher than the first reference temperature, the start temperature is set to a second start temperature that is higher than the first start temperature; When the detected temperature is greater than the first reference temperature and less than the second reference temperature, the start temperature is set to increase as the detected temperature increases within the range from the first start temperature to the second start temperature.

[0009] As described in claim 3, preferably, before the start of the cleaning cooling operation, the temperature is detected by the room temperature sensor or an outside air temperature sensor that detects the outside air temperature, When the detected temperature is equal to or lower than a reference temperature, the start temperature of the heating operation, which is set when starting the drying operation, is set to a first start temperature; When the detected temperature exceeds the reference temperature, the start temperature is set to a second start temperature that is higher than the first start temperature. Effect of the Invention

[0010] In claim 1, the control unit controls the compressor, the expansion valve, and the indoor fan to execute a cleaning cooling operation, and then execute a drying operation to dry the surface of the indoor heat exchanger. Furthermore, the control unit starts the drying operation from a heating operation, detects the room temperature by a room temperature sensor during the drying operation, and switches between the heating operation and the fan operation when the detected room temperature reaches a preset temperature. Compared to a drying operation that executes only a predetermined high-temperature heating operation, executing the drying operation by combining the heating operation and the fan operation makes it possible to accurately control the room temperature and suppress the rise in the room temperature. It also makes it possible to reduce power consumption.

[0011] In claim 2, before the start of the washing cooling operation, the temperature is detected by a room temperature sensor or an outside air temperature sensor that detects the outside air temperature. When the detected temperature is equal to or lower than a first reference temperature, the start temperature of the heating operation that is set when the drying operation is started is set to the first start temperature. When the detected temperature is equal to or higher than a second reference temperature that is higher than the first reference temperature, the start temperature is set to a second start temperature that is higher than the first start temperature. When the detected temperature is higher than the first reference temperature and lower than the second reference temperature, the start temperature is set to be higher within the range from the first start temperature to the second start temperature as the room temperature increases.

[0012] In other words, as the room temperature decreases, the start temperature of the heating operation set when starting the drying operation is also set lower or constant. Compared to the drying operation in which only the high-temperature heating operation is performed, the room temperature can be further prevented from becoming too high.

[0013] In claim 3, before the start of the washing cooling operation, the temperature is detected by a room temperature sensor or an outside air temperature sensor that detects the outside air temperature. When the detected temperature is equal to or lower than a reference temperature, the start temperature of the heating operation that is set when the drying operation is started is set to a first start temperature. When the detected temperature exceeds the reference temperature, the start temperature is set to a second start temperature that is higher than the first start temperature.

[0014] In other words, as the room temperature decreases, the start temperature of the heating operation set when starting the drying operation is also set lower or constant. Compared to the drying operation in which only the high-temperature heating operation is performed, the room temperature can be further prevented from becoming too high. [Brief description of the drawings]

[0015] [Figure 1] 1 is a schematic diagram of an air conditioner according to an embodiment. [Diagram 2] FIG. 2 is a block diagram of the air conditioner shown in FIG. [Diagram 3] 4 is a flowchart illustrating the control content of a cleaning cooling operation of the air conditioner shown in FIG. [Figure 4] 4 is a flowchart illustrating the control of a drying operation of the air conditioner shown in FIG. [Diagram 5] 11 is a map showing the relationship between the room temperature before the start of a cleaning cooling operation and the start temperature that is set when starting a heating operation. [Figure 6] 11 is a diagram illustrating switching between a heating operation and an air blowing operation during a drying operation. FIG. [Figure 7] 11 is a map showing the relationship between the outside air temperature before the start of a cleaning cooling operation and the start temperature that is set when starting a heating operation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to the accompanying drawings.

[0017] <Example 1> 1 shows an air conditioner 10 (air conditioner) equipped with a refrigerant circuit 11 through which a refrigerant flows. The air conditioner 10 has the function of performing a cooling operation to cool the room R, and a heating operation to warm the room R. The refrigerant circuit 11 includes an outdoor unit 20 arranged outside Ou, and an indoor unit 30 arranged inside the room R. Hereinafter, unless otherwise specified, the direction in which the refrigerant circulates is based on the cooling operation.

[0018] The outdoor unit 20 has a four-way switching valve 21 that switches the direction in which the refrigerant circulates during cooling operation and heating operation, a compressor 22 through which the refrigerant that has passed through this four-way switching valve 21 flows and compresses the refrigerant, an outdoor heat exchanger 23 through which the refrigerant that has been compressed in the compressor 22 and has become high temperature and high pressure flows, a propeller fan 24 that blows air toward the outdoor heat exchanger 23, and an expansion valve 25 that reduces the pressure of the refrigerant that has passed through the outdoor heat exchanger 23.

[0019] The indoor unit 30 is hung on a wall Wa in the room R. The indoor unit 30 has an indoor fan 31 that takes in air from the room and blows air into the room, an indoor heat exchanger 32 that cools the air taken in by the indoor fan 31, and a case 33 that houses the indoor fan 31 and the indoor heat exchanger 32.

[0020] The case 33 has an air outlet 33a which serves as an outlet for the air blown out by the indoor fan 31. A left-right louver 34 for adjusting the left-right direction of the blown air and a top-bottom louver 35 for adjusting the up-down direction of the blown air are arranged in the air outlet 33a.

[0021] Cooling operation will now be described. The refrigerant that has been made high temperature and high pressure by the compressor 22 exchanges heat with outside air in the outdoor heat exchanger 23, releasing heat. At this time, the propeller fan 24 rotates to forcibly flow the outside air around the outdoor heat exchanger 23, promoting the heat exchange. The refrigerant that has passed through the outdoor heat exchanger 23 and released heat is reduced in pressure in the expansion valve 25, and its temperature drops. The refrigerant with the lowered temperature flows to the indoor heat exchanger 32.

[0022] The low-temperature refrigerant that has flowed into the indoor heat exchanger 32 exchanges heat with the air in the room R in the indoor heat exchanger 32, cooling the air in the room R. The cooled air is sent into the room R by the indoor fan 31. The indoor fan 31 forcibly flows the air around the periphery of the indoor heat exchanger 32, promoting heat exchange with the refrigerant.

[0023] During heating operation, the four-way valve 21 switches the flow path of the refrigerant to circulate the refrigerant in the opposite direction to that during cooling operation. Furthermore, the air conditioner 10 also has a function of performing a fan operation in which the indoor fan 31 blows air into the room without performing heat exchange by the indoor heat exchanger 32.

[0024] Fig. 2 shows a control block diagram of the air conditioner device 10 (see Fig. 1). The indoor unit 30 incorporates an indoor fan 31, an indoor control unit 40 (control unit) that controls the left and right louvers 34, and the up and down louvers 35, a room temperature sensor 41 that detects the room temperature, an indicator lamp 42 that displays the operating status by the indoor control unit 40, and a remote control transmitting and receiving unit 43 that transmits and receives predetermined information to and from the remote control 12.

[0025] The indoor control unit 40 has a memory unit 44 in which data received via the remote control transmitter / receiver unit 43, detection values ​​of the room temperature sensor 41, the set temperature and reference time described below, and other specified programs, etc. are stored, as well as timers t1 and t2 which measure the elapsed time of various operations.

[0026] The outdoor unit 20 has an outdoor control unit 45 that is electrically connected to the indoor control unit 40. The indoor control unit 40 is capable of controlling the four-way switching valve 21, the compressor 22, the propeller fan 24, and the expansion valve 25 via the outdoor control unit 45.

[0027] The air conditioner 10 also has a function of performing a cleaning operation to clean dust adhering to the surface of the indoor heat exchanger 32 (see FIG. 1). The control of the cleaning operation of the air conditioner 10 will be described below.

[0028] When a signal to start a cleaning operation is sent from the remote control 12 (see Figure 2) to the indoor control unit 40, or when certain conditions are met after the end of cooling or heating operation (for example, a certain amount of time has passed since the end of the previous cleaning operation), the indoor control unit 40 starts the cleaning operation by turning on the indicator lamp 42 to indicate that a cleaning operation is being performed.

[0029] The cleaning operation includes a cleaning cooling operation in which condensation is used to generate water droplets on the surface of the indoor heat exchanger 32 to wash away dust, and a drying operation which is performed after the cleaning cooling operation to dry the surface of the indoor heat exchanger 32.

[0030] (Cleaning cooling operation) Please refer to Fig. 3. When the cleaning operation is started (START), in step St1, the first timer t1 starts from "0".

[0031] In step St2, the indoor control unit 40 acquires the room temperature Tr1 detected by the room temperature sensor 41. The room temperature Tr1 is a temperature detected before the start of the cleaning cooling operation.

[0032] In step St3, the cleaning cooling operation is performed. The cleaning cooling operation is performed by the outdoor control unit 45 receiving a command from the indoor control unit 40 and controlling the compressor 22, the expansion valve 25, and the four-way switching valve 21, in the same manner as the normal cooling operation.

[0033] The cleaning cooling operation is performed based on preset conditions. For example, the set temperature for the cleaning cooling operation is a predetermined temperature, and the left and right louvers 34 and the up and down louvers 35 are fixed at the positions for maximum airflow. The airflow is changed as appropriate.

[0034] After the start of the cleaning cooling operation, in step st4, it is determined whether the time measured by the first timer t1 (continuation time of the cleaning cooling operation) has passed a preset reference time m1 (t1>m1).

[0035] When the time measured by the first timer t1 has passed the reference time m1 (t1>m1), the process proceeds to the flowchart of the drying operation shown in FIG.

[0036] If the time measured by the first timer t1 has not passed the reference time m1 (t1≦m1), in step St5, the indoor control unit 40 acquires the room temperature Tr2 detected by the room temperature sensor 41. The room temperature Tr2 is a temperature detected during the cleaning cooling operation.

[0037] Then, in step St6, it is determined whether the room temperature Tr2 has fallen below the preset temperature Tp due to the cleaning cooling operation (Tr2 < Tp). If the room temperature Tr2 is equal to or higher than the set temperature Tp (Tr2 ≧ Tp), the cleaning cooling operation continues. If the room temperature Tr2 has fallen below the set temperature Tp1 (Tr2 < Tp), the process proceeds to the flowchart of the drying operation shown in FIG. 4.

[0038] (Drying operation) Please refer to Fig. 4. The indoor control unit 40 starts the drying operation from the heating operation. Furthermore, when the room temperature reaches a preset temperature, the indoor control unit 40 switches between the heating operation and the fan operation. This will be explained in detail below.

[0039] In step St7, the second timer t2 starts from "0".

[0040] (Heating operation start temperature Ts) In step St8, the start temperature Ts of the heating operation, which is set when the drying operation is started, is determined according to the room temperature Tr1 (the room temperature detected before the start of the cleaning cooling operation (see step St2)).

[0041] FIG. 5 is a map in the form of a graph showing the relationship between room temperature Tr1 and start temperature Ts. When room temperature Tr1 is equal to or lower than the first reference temperature Ta1 (Tr1 ≦ Ta1), the start temperature Ts is set to the first start temperature Ts1 (Ts = Ts1). A temperature higher than the first reference temperature Ta1 is set to the second reference temperature Ta2 (Ta1 < Ta2). A temperature higher than the first start temperature Ts1 is set to the second start temperature Ts2 (Ts1 < Ts2). When room temperature Tr1 is equal to or higher than the second reference temperature Ta2 (Tr1 ≧ Ta2), the start temperature Ts is set to the second start temperature Ts2 (Ts = Ts2).

[0042] When the room temperature Tr1 is greater than the first reference temperature Ta1 and less than the second reference temperature Ta2 (Ta1 < Tr1 < Ta2), the start temperature Ts is set within the range from the first start temperature Ts1 to the second start temperature Ts2 (Ts1 ≦ Ts ≦ Ts2) such that the higher the room temperature Tr1, the higher the start temperature Ts.

[0043] Returning to Fig. 4, in step St9, the heating operation is performed at the start temperature Ts determined in step St8. The up-down louvers 35 and the left-right louvers 34 are fixed at the positions at which the air volume is maximum. The air volume is changed as appropriate.

[0044] After the heating operation starts, in step St10, the indoor control unit 40 acquires the room temperature Tr3 detected by the room temperature sensor 41. The room temperature Tr3 is a temperature detected during the drying operation.

[0045] When the drying operation is started, the heating operation is performed, and the room temperature Tr3 rises (see FIG. 6). In step St11, it is determined whether the room temperature Tr3 has reached a preset switching temperature Tc for switching between the heating operation and the fan operation (Tr3≧Tc).

[0046] When the room temperature Tr3 reaches the switching temperature Tc (Tr3 ≧ Tc), in step St12, the indoor control unit 40 stops the heating operation and switches to the fan operation.

[0047] In step St13, the indoor control unit 40 acquires the room temperature Tr3 detected by the room temperature sensor 41. See Fig. 6. Immediately after switching from heating operation to fan operation, the room temperature Tr3 continues to rise due to residual heat of the indoor heat exchanger 32. If the fan operation continues thereafter, for example, the room temperature Tr3 may continue to remain constant, or the room temperature Tr3 may start to decrease after remaining constant.

[0048] In step St14, it is determined whether the room temperature Tr3 has fallen below the switching temperature Tc (Tr3<Tc). If the room temperature Tr3 has fallen below the switching temperature Tc (Tr3<Tc), the indoor control unit 40 stops the air blowing operation and switches to heating operation.

[0049] The start temperature Ts of the heating operation to be restarted is the temperature determined in step st8.

[0050] If the room temperature Tr3 does not reach the switching temperature Tc in step st11, it is determined in step st15 whether the time measured by the second timer t2 (the duration of the drying operation) has passed a preset reference time m2.

[0051] If the time measured by the second timer t2 does not reach the reference time m2, the heating operation continues. If the time measured by the second timer t2 reaches the reference time m2, the indoor control unit 40 stops the heating operation and ends the cleaning operation (END).

[0052] Similarly, if the room temperature Tr3 does not fall below the switching temperature Tc in step st14, it is determined in step st16 whether the time measured by the second timer t2 (the duration of the drying operation) has passed the reference time m2.

[0053] If the time measured by the second timer t2 does not reach the reference time m2, the fan operation continues. If the time measured by the second timer t2 reaches the reference time m2, the indoor control unit 40 stops the fan operation and the cleaning operation ends (ends). Note that if the time measured by the second timer t2 reaches the reference time m2 during the fan operation, the indoor control unit 40 may further perform the heating operation for a predetermined time and then end the cleaning operation. This can prevent the indoor heat exchanger 32 from remaining dry.

[0054] (Effects of the embodiment) (Control of room temperature Tr3 by heating operation and fan operation) Refer to Fig. 4. The indoor control unit 40 starts the drying operation from the heating operation (see step st9). Furthermore, when the room temperature Tr3 reaches the switching temperature Tc, the indoor control unit 40 switches between the heating operation and the fan operation (see steps st11 and st14).

[0055] Compared to a drying operation in which only a heating operation at a predetermined high temperature is performed, the drying operation is performed by combining a heating operation and a ventilation operation, so that the room temperature can be controlled with high precision and the rise in the room temperature can be suppressed. Power consumption can also be reduced.

[0056] See Fig. 6. In addition, the switching temperature Tc is set lower than the start temperature Ts of the heating operation that is set when starting the drying operation (Tc < Ts). Since the operation is switched from the heating operation to the fan operation before the room temperature Tr3 reaches the start temperature Ts, the room temperature Tr3 is less likely to exceed the start temperature Ts, and the rise in the room temperature Tr3 can be further suppressed.

[0057] (Heating operation start temperature Ts according to room temperature Tr1) Please refer to Fig. 4. In step St8, the start temperature Ts of the heating operation, which is set when the drying operation is started, is determined according to the room temperature Tr1 (the room temperature immediately before the start of the cleaning cooling operation (see step st2)). In detail, as shown in Fig. 5, as the room temperature Tr1 becomes lower, the start temperature Ts of the heating operation is also set lower or constant. Compared to performing the heating operation at a constant set temperature regardless of the room temperature, it is possible to prevent the room temperature from becoming too high due to the drying operation.

[0058] <Example 2> Please refer to Figures 2 and 4. The outdoor unit 20 is also equipped with an outdoor air temperature sensor 26. The start temperature Ts of the heating operation, which is set when starting the drying operation, may be set according to the outdoor air temperature To detected by the outdoor air temperature sensor 26 before the start of the cleaning cooling operation, instead of the room temperature Tr1. Furthermore, the start temperature Ts may be set based on the map of Figure 7 instead of the map of Figure 5.

[0059] Refer to Fig. 7. When the outside air temperature To is equal to or lower than the reference temperature Tb, the start temperature Ts is set to the first start temperature Ts1. When the outside air temperature To exceeds the reference temperature Tb, the start temperature Ts is set to the second start temperature Ts2, which is higher than the first start temperature Ts1. In other words, when the outside air temperature To is equal to or lower than the reference temperature Tb, the start temperature Ts is set low. Compared to performing heating operation at a constant set temperature regardless of the room temperature, this prevents the room temperature from becoming too high.

[0060] As long as the functions and effects of the present invention are exhibited, the present invention is not limited to the examples. [Industrial Applicability]

[0061] The air conditioner of the present invention is suitable for use as a home air conditioner. [Explanation of symbols]

[0062] 10…Air conditioning equipment (air conditioner) 11...Refrigerant circuit 21...Four-way switching valve 22...Compressor 25…Expansion valve 26...Outside air temperature sensor 32…Indoor heat exchanger 40...Indoor control unit (control unit) 41…Room temperature sensor Tr1: Temperature detected before the start of the cleaning cooling operation (room temperature) To: Detected before the start of the cleaning cooling operation (outdoor temperature) Tc: Temperature at which heating and fan operation are switched Tr3: Room temperature detected by the room temperature sensor during drying operation Ta1…1st reference temperature Ta2…Second reference temperature Ts: The starting temperature for heating operation that is set when starting drying operation Ts1…1st starting temperature Ts2…Second starting temperature Tb…Reference temperature

Claims

1. A refrigerant circuit through which a refrigerant circulates; a compressor provided in the refrigerant circuit and capable of compressing a refrigerant; and an expansion valve provided in the refrigerant circuit and configured to reduce a pressure of the refrigerant; a four-way valve provided in the refrigerant circuit for switching a flow direction of the refrigerant; an indoor heat exchanger provided in the refrigerant circuit for exchanging heat between the refrigerant and indoor air; An indoor fan that takes in air from the room and blows air into the room; A room temperature sensor for detecting a room temperature; a control unit that controls the compressor, the expansion valve, the four-way switching valve, and the indoor fan to execute a heating operation for heating the room, a blowing operation for blowing air into the room by the indoor fan without performing heat exchange by the indoor heat exchanger, and a cleaning cooling operation for cleaning the surface of the indoor heat exchanger by causing condensation on the surface of the indoor heat exchanger, The control unit controls the compressor, the expansion valve, and the indoor fan to perform a drying operation to dry a surface of the indoor heat exchanger after performing the cleaning cooling operation, The control unit starts the drying operation from the heating operation, detects a room temperature by the room temperature sensor during the drying operation, and switches between the heating operation and the air blowing operation when the detected room temperature reaches a preset temperature. Before the start of the cleaning cooling operation, the temperature is detected by the room temperature sensor or an outside air temperature sensor that detects the outside air temperature, When the detected temperature is equal to or lower than a first reference temperature, the start temperature of the heating operation, which is set when starting the drying operation, is set to a first start temperature; When the detected temperature is equal to or higher than a second reference temperature that is higher than the first reference temperature, the start temperature is set to a second start temperature that is higher than the first start temperature; an air conditioner, wherein, when the detected temperature is greater than the first reference temperature and less than the second reference temperature, the start temperature is set to increase as the detected temperature increases within a range from the first start temperature to the second start temperature.

2. A refrigerant circuit through which a refrigerant circulates; a compressor provided in the refrigerant circuit and capable of compressing a refrigerant; and an expansion valve provided in the refrigerant circuit and configured to reduce a pressure of the refrigerant; a four-way valve provided in the refrigerant circuit for switching a flow direction of the refrigerant; an indoor heat exchanger provided in the refrigerant circuit for exchanging heat between the refrigerant and indoor air; An indoor fan that takes in air from the room and blows air into the room; A room temperature sensor for detecting a room temperature; a control unit that controls the compressor, the expansion valve, the four-way switching valve, and the indoor fan to execute a heating operation for heating the room, a blowing operation for blowing air into the room by the indoor fan without performing heat exchange by the indoor heat exchanger, and a cleaning cooling operation for cleaning the surface of the indoor heat exchanger by causing condensation on the surface of the indoor heat exchanger, The control unit controls the compressor, the expansion valve, and the indoor fan to perform a drying operation to dry a surface of the indoor heat exchanger after performing the cleaning cooling operation, The control unit starts the drying operation from the heating operation, detects a room temperature by the room temperature sensor during the drying operation, and switches between the heating operation and the air blowing operation when the detected room temperature reaches a preset temperature. Before the start of the cleaning cooling operation, the temperature is detected by the room temperature sensor or an outside air temperature sensor that detects the outside air temperature, When the detected temperature is equal to or lower than a reference temperature, the start temperature of the heating operation, which is set when starting the drying operation, is set to a first start temperature; When the detected temperature exceeds the reference temperature, the start temperature is set to a second start temperature that is higher than the first start temperature.

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