JP2022131144A - Dryer - Google Patents

Abstract

To provide a technology, for a dryer which is placed in an indoor setting and includes an exhaust air duct through which exhaust air which has been discharged from a drying chamber through an exhaust air passage is discharged to the outdoor atmosphere, with which the occurrence of condensation on the outer surface of the exhaust air duct can be properly prevented through adopting a low-cost and rational structure.SOLUTION: The invention includes: a condensation occurrence determination unit which determines whether or not condensation on an outer surface 22o of an exhaust air duct 22 occurs; and a condensation prevention controlling unit which, when the condensation occurrence determination unit determines that condensation occurs on the outer surface 22o of the exhaust air duct 22, performs a condensation prevention air sending operation in which an exhaust air fan 20 is activated.SELECTED DRAWING: Figure 1

Description

The present invention relates to a drying apparatus for drying objects such as wet clothes housed in a drying chamber.

2. Description of the Related Art There is known a drying apparatus provided with an exhaust duct installed indoors to guide the exhaust air discharged from a drying chamber through an exhaust air passage to the outside (see Patent Document 1, for example). In such a drying apparatus, while operating an exhaust fan that sends out the exhaust air taken from the drying chamber to the exhaust air passage, the hot air generated by the hot air generation unit is introduced into the drying chamber through the hot air passage. It is configured to be able to execute a drying operation for drying an object to be dried such as wet clothes housed in the drying chamber.

JP 2013-148299 A

The indoor air pressure where the dryer is installed may be lower than the outdoor air pressure due to factors such as the indoor ventilation conditions. Especially in cold weather such as winter, when the air pressure in the room is lower than the outdoor air pressure when the drying operation is not performed, cold air flows into the exhaust duct of the drying device from the outdoors, and the cold air that flows in is exhausted. The duct itself is cooled and as a result condensation may form on the outer surface of the cooled exhaust duct.
As a method to prevent the occurrence of condensation on the outer surface of the exhaust duct, generally, the outer surface of the exhaust duct is completely covered with a heat insulating material, thereby preventing the outer surface of the cooled exhaust duct from falling indoors. There is a way to prevent air contact. However, such a method increases the material cost and construction cost of the heat insulating material, which is a major obstacle to expanding sales of the drying apparatus and improving the installation rate.
In addition, in order to simplify or omit the installation of heat insulating material in the exhaust duct, an electric shutter that operates based on the outside air temperature is installed inside the exhaust duct to prevent cold air from entering the exhaust duct from the outside. However, the addition of such an electric shutter causes an increase in the initial cost, and causes problems such as malfunction due to clothes dust discharged from the drying chamber into the exhaust duct.
In view of this situation, the main object of the present invention is to provide a drying apparatus having an exhaust duct installed indoors for guiding the exhaust air discharged from the drying chamber through the exhaust air passage to the outside, and adopting a low-cost and rational configuration. However, the object of the present invention is to provide a technique capable of appropriately preventing the occurrence of dew condensation on the outer surface of the exhaust duct.

A first characteristic configuration of the present invention includes a drying chamber in which an object to be dried is accommodated and hot air is introduced from a hot air inlet;
a hot air generating unit capable of generating the hot air and supplying it to a hot air path leading to the hot air inlet;
an exhaust air passage installed indoors and connected to an exhaust duct leading to the outdoors;
an exhaust fan that takes in exhaust air from the drying chamber and sends it out to an exhaust air passage;
An operation capable of executing a drying operation of operating the exhaust fan and the hot air generating unit to supply warm air to the drying chamber and exhaust the exhaust air to dry the object to be dried stored in the drying chamber. A drying apparatus comprising a control unit,
a dew condensation determination unit that determines whether dew condensation occurs on the outer surface of the exhaust duct;
and a dew condensation prevention control section that executes dew condensation prevention air blowing operation for operating the exhaust fan when the dew condensation generation determination section determines that dew condensation occurs on the outer surface of the exhaust duct.

According to this configuration, when the dew condensation prevention air blowing operation is executed and the exhaust fan is operated, the indoor air flows into the drying chamber through the warm air passage, and the indoor air that has flowed in is discharged from the exhaust air passage and the exhaust duct. After circulating inside, it is discharged to the outside. When there is a possibility that dew condensation occurs on the outer surface of the exhaust duct due to the fact that the exhaust duct itself is cooled by the cold air that has flowed into the interior when the drying operation is not performed. , the dew condensation prevention air blowing operation as described above is executed in accordance with the dew condensation determination by the dew condensation determination unit. Then, indoor air flows through the exhaust duct from the drying chamber toward the outside, so the temperature of the exhaust duct itself is the temperature of the indoor air (in this application, the temperature of the indoor air is sometimes referred to as the "inside air temperature". ) can be raised to approximately the same temperature or higher. Therefore, even if the outer surface of the exhaust duct is not covered with a heat insulating material and the indoor air comes into contact with the outer surface, it is possible to appropriately prevent the occurrence of dew condensation on the outer surface of the exhaust duct.
Therefore, according to the present invention, in a drying apparatus provided with an exhaust duct installed indoors for guiding the exhaust air discharged from the drying chamber through the exhaust air passage to the outside, the configuration outside the exhaust duct is inexpensive and rational. It is possible to provide a technique that can appropriately prevent the occurrence of dew condensation on the surface.

A second characteristic configuration of the present invention is an exhaust air passage temperature detection unit that detects the temperature of the exhaust air passage as an exhaust air passage temperature;
an inside air temperature detection unit that detects the temperature of the indoor air as the inside air temperature,
The dew condensation generation determination unit determines that there is a temperature difference equal to or greater than a predetermined set temperature range between the exhaust air passage temperature detected by the exhaust air passage temperature detection unit and the inside air temperature detected by the inside air temperature detection unit. In this case, it is determined that dew condensation occurs on the outer surface of the exhaust duct.

According to this configuration, the exhaust air duct temperature detected by the exhaust air duct temperature detection unit is substantially the same as the temperature of the exhaust duct itself. Therefore, by ascertaining the temperature difference in the inside air temperature with respect to the exhaust air passage temperature, it is possible to ascertain the temperature difference in the inside air temperature with respect to the temperature of the exhaust duct itself. Therefore, the dew condensation generation determination unit utilizes this fact, and when there is a temperature difference equal to or greater than a predetermined set temperature range between the exhaust air passage temperature and the inside air temperature, specifically, the exhaust air passage temperature exceeds the inside air temperature. When the temperature is lower than the set temperature range, it can be determined that dew condensation occurs on the outer surface of the exhaust duct because the outer surface of the exhaust duct is lower than the inside air temperature.

A third characteristic configuration of the present invention is, as the inside air temperature detection unit,
a hot air passage temperature detecting unit for detecting the temperature of the hot air passage when the hot air generating unit is not operating as the inside air temperature; The point is that at least one of the drying chamber temperature detection units that detect the temperature is provided.

According to this configuration, the temperature of the hot air path detected by the hot air path temperature detecting part and the temperature of the drying chamber when the hot air generating part does not generate hot air and are not operating The temperature of the drying chamber detected by the temperature detection unit is substantially the same as the inside air temperature, which is the temperature of the indoor air flowing into the warm air path and the drying chamber. Therefore, by grasping the temperature difference between the temperature of the hot air passage and the drying chamber with respect to the temperature of the exhaust air passage, it is possible to grasp the temperature difference of the inside air temperature with respect to the temperature of the exhaust duct itself. Therefore, the dew condensation determination unit utilizes this fact, and when there is a temperature difference equal to or greater than a predetermined set temperature range between the temperature of the exhaust air passage and the temperature of the hot air passage or the drying chamber, specifically, When the temperature of the exhaust duct is lower than the set temperature range compared to the temperature of the hot air duct and the drying chamber, the outer surface of the exhaust duct is cooler than the inside air temperature, causing condensation on the outer surface of the exhaust duct. can be determined to occur.

A fourth characteristic configuration of the present invention is an exhaust air passage temperature detection unit that detects the temperature of the exhaust air passage as an exhaust air passage temperature;
an outside air inflow detection unit that detects the inflow of outside air into the exhaust duct from the outdoors,
The dew condensation occurrence determination unit detects the inflow of outside air into the exhaust duct by the outside air inflow detection unit, and determines that the exhaust air passage temperature detected by the exhaust air passage temperature detection unit is a predetermined set exhaust air passage. It is determined that dew condensation occurs on the outer surface of the exhaust duct when the temperature drops below the temperature.

According to this configuration, when the outside air inflow detection unit detects the inflow of outside air into the exhaust duct, the exhaust air passage temperature detected by the exhaust air passage temperature detection unit is the temperature of the cold air flowing into the exhaust duct. It roughly corresponds to the temperature. Therefore, the dew condensation generation determination unit utilizes this fact to reduce the temperature of the exhaust duct, which corresponds to the temperature of the cold air that has flowed into the exhaust duct, to a predetermined set duct internal temperature that is set according to, for example, the inside air temperature. In this case, it can be determined that dew condensation occurs on the outer surface of the exhaust duct because the temperature of the outer surface of the exhaust duct is lower than the inside air temperature.

A fifth characteristic configuration of the present invention includes a warm season determination unit that determines whether it is a warm season in which dew condensation does not occur on the outer surface of the exhaust duct,
The dew condensation prevention control section prohibits execution of the dew condensation prevention air blowing operation when the warm season determination section determines that it is the warm season.

According to this configuration, when the warm season determination unit determines that it is the warm season, the dew condensation prevention control unit prohibits execution of the dew condensation prevention air blowing operation, so no dew condensation occurs on the outer surface of the exhaust duct. Useless exhaust fan operation in warm weather can be prevented.

A sixth characteristic configuration of the present invention is that the dew condensation prevention control section operates the hot air generating section to supply hot air to the drying chamber in the dew condensation prevention air blowing operation.

According to this configuration, by operating the hot air generating section in the dew condensation prevention air blowing operation to introduce hot air into the drying chamber, hot air flows from the drying chamber to the outside in the exhaust duct. In addition, the temperature of the exhaust duct itself can be raised to the temperature of the inside air or higher, and the occurrence of dew condensation on the outer surface of the exhaust duct can be prevented more reliably. Furthermore, prior to the drying operation, by executing the dew condensation prevention blowing operation while operating the hot air generating unit, the temperature of the drying chamber can be increased in advance, so the operation time (drying time) of the next drying operation can be shortened to improve energy saving and usability.

Schematic diagram of clothes drying device A block diagram showing the configuration of a control unit included in the clothes drying apparatus.

An embodiment of a drying apparatus according to the present invention will be described based on the drawings.
A clothes drying apparatus 1 of this embodiment shown in FIG. 1 is a drying apparatus for drying an object A to be dried such as clothes. A rotating drum 12 into which an object to be dried A is put into a drying chamber 13 formed inside as a rotator, a hot air generating unit 30 for supplying hot air HG to the drying chamber 13, and exhaust from the drying chamber 13 An exhaust air passage 23 for discharging EG, an exhaust fan 20, and a controller 50 for controlling the operation of the warm air generator 30 and the exhaust fan 20 are provided.

The rotating drum 12 is rotatably supported around a substantially horizontal rotating shaft and driven to rotate by a drive motor 25 via a belt B12. Inside the rotary drum 12, there is formed a drying chamber 13 in which the object A to be dried is accommodated and hot air HG is introduced from a hot air inlet 36. As shown in FIG. On the front side wall surface of the drying chamber 13, a hot air inlet 36 is opened facing the drying chamber 13. At the rear side of the drying chamber 13, an exhaust fan 20 is operated through an opening in which a filter 17 is mounted. It communicates with the primary side (suction side).
A drying chamber thermistor 13t (an example of a drying chamber temperature detector) for measuring a drying chamber temperature T13, which is the temperature of the drying chamber 13, is provided on the front side wall surface of the drying chamber 13. As shown in FIG.

The hot air generating section 30 is configured to generate hot air HG and supply it to the hot air path 35 leading to the hot air inlet 36 , and functions as the hot air generating section 30 below the rotating drum 12 . A burner 31 is provided. The burner 31 burns the fuel gas supplied through the fuel supply valve 33 with the combustion air CA that blows out from the fuel nozzle 32 and flows into the hot air passage 35 from the housing 10 to generate high-temperature flue gas. . Then, this high-temperature combustion exhaust gas is introduced into the drying chamber 13 from the hot air inlet 36 through the hot air path 35 as the hot air HG. Into the housing 10, the indoor air RA can flow from the indoor R through the opening formed in the bottom surface, and the outflowing indoor air RA is used as the combustion air CA. 35 can flow.
The hot air passage 35 is provided with a hot air passage thermistor 35t (an example of a hot air passage temperature detection unit) that measures a hot air passage temperature T35 that is the temperature of the hot air passage 35 .

The exhaust air passage 23 is an air passage installed indoors R and connected to the exhaust duct 22 leading to the outdoors O. As shown in FIG. The exhaust fan 20 is a fan that takes in the exhaust EG from the drying chamber 13 and sends it out into the exhaust air passage 23 and the exhaust duct 22, and is rotationally driven by the drive motor 25 via the belt B20. By rotating the exhaust fan 20 and operating it, the air can be ventilated from the drying chamber 13 to the outdoors O through the exhaust air passage 23 and the exhaust duct 22 .
The exhaust air path 23 is provided with an exhaust air path thermistor 23t (an example of an exhaust air path temperature detection unit) that measures an exhaust air path temperature T23, which is the temperature of the exhaust air path 23 .
Further, inside the exhaust duct 22, a wind pressure switch 24 (an example of an outside air inflow detection unit) is provided for detecting the inflow of outside air from the outdoors O into the exhaust air passage 23 and the inside of the exhaust duct 22. FIG.

The control unit 50 functions as an operation control unit 51 that executes a drying operation or the like for drying the object A put into the drying chamber 13, as shown in FIG. That is, in the drying operation executed by the operation control unit 51, the exhaust fan 20 is operated in a form of being rotationally driven by the drive motor 25, and the fuel supply valve 33 is opened to supply fuel gas to the burner 31 for combustion. The burner 31 (hot air generating section 30) is operated in such a manner as to Then, the hot air HG is supplied to the drying chamber 13 by the burner 31 and the exhaust gas EG is discharged by the exhaust fan 20, so that the hot air HG is applied to the drying object A accommodated in the drying chamber 13. Allow to dry.
In the drying operation, the operation control unit 51 checks the operation of the burner 31 based on the warm air path temperature T35 measured by the hot air path thermistor 35t, and controls the drying chamber temperature measured by the drying chamber thermistor 13t. The dryness of the object to be dried A can be estimated based on the exhaust air duct temperature T23 measured by T13 and the exhaust air duct temperature T23.

In the configuration of the clothes drying apparatus 1 as described above, cold air flows from the outdoors O into the exhaust duct 22 when the atmospheric pressure of the indoor R is lower than that of the outdoor O when the drying operation is not performed, especially in cold weather such as winter. There is concern that the exhaust duct 22 itself will be cooled by the inflowing cool air, and dew condensation will occur on the cooled outer surface 22o of the exhaust duct 22. FIG. Therefore, the clothes drying apparatus 1 of the present embodiment has a characteristic configuration that can appropriately prevent the occurrence of dew condensation on the outer surface 22o of the exhaust duct 22 while adopting an inexpensive and rational configuration. The details are explained below.

Although details will be described later, the clothes drying apparatus 1 of the present embodiment includes an inside air temperature detection unit 53, a dew condensation occurrence determination unit 54, a warm season determination unit 55, and a dew condensation prevention unit 50 in a form in which the control unit 50 functions. A control unit 56 is provided.

The inside air temperature detection unit 53 is means for detecting the temperature of the indoor air RA as the inside air temperature Tr. However, in this embodiment, the inside air temperature Tr is detected using the measurement result of at least one of the hot air path thermistor 35t and the drying chamber thermistor 13t.
That is, when the hot air generator 30 does not generate the hot air HG and is not in operation, the hot air path temperature T35 measured by the hot air path thermistor 35t and the temperature T35 measured by the drying chamber thermistor 13t are measured. The drying chamber temperature T<b>13 is approximately equal to the inside air temperature Tr, which is the temperature of the indoor air RA flowing into the warm air path 35 and the drying chamber 13 . Therefore, the inside air temperature detection unit 53 detects the hot air path temperature T35 and the drying chamber temperature measured by the hot air path thermistor 35t and the drying chamber thermistor 13t when the hot air generating unit 30 is not operated and the drying operation is not performed. T13 can be detected as the inside air temperature Tr.

The dew condensation determination unit 54 is means for determining whether dew condensation occurs on the outer surface 22 o of the exhaust duct 22 .
Specifically, the dew condensation generation determining unit 54 can determine whether dew condensation occurs on the outer surface 22o of the exhaust duct 22 by a plurality of determination methods described below.
First, in the first determination method, the dew condensation generation determination unit 54 sets a predetermined value between the exhaust air passage temperature T23 detected by the exhaust air passage thermistor 23t and the inside air temperature Tr detected by the inside air temperature detection unit 53. Dew condensation is determined to occur on the outer surface 22o of the exhaust duct 22 when the temperature difference is equal to or greater than the temperature range (for example, the temperature range within the range of 10° C. to 20° C.).
That is, when the exhaust air passage temperature T23 is lower than the inside air temperature Tr by at least the set temperature range, the outer surface 22o of the exhaust duct 22 is lower than the inside air temperature Tr. It is determined that condensation occurs on the surface 22o.

In the second determination method, the dew condensation occurrence determination unit 54 detects the inflow of outside air into the exhaust air path 23 and the exhaust duct 22 by the wind pressure switch 24, and detects the presence of the exhaust air path detected by the exhaust air path thermistor 23t. Dew condensation is determined to occur on the outer surface 22o of the exhaust duct 22 when the temperature T23 drops below a predetermined set exhaust air passage temperature (for example, a temperature within the range of 10° C. to 30° C.).
As another determination method, the dew condensation determination unit 54 determines that dew condensation occurs on the outer surface 22o of the exhaust duct 22 when the outside air temperature (the temperature of the outdoor O) becomes equal to or lower than a predetermined set outside air temperature. can also

The dew condensation prevention control unit 56 is configured to perform dew condensation prevention air blowing operation for operating the exhaust fan 20 when the dew condensation occurrence determination unit 54 determines that dew condensation occurs on the outer surface 22o of the exhaust duct 22. It is
That is, when the drying operation is not performed, the exhaust duct 22 itself is cooled by the cool air that flows into the exhaust duct 22, and condensation occurs on the outer surface 22o of the exhaust duct 22. If there is a possibility that dew condensation will occur, the dew condensation prevention air blowing operation is executed in accordance with the determination of dew condensation occurrence by the dew condensation occurrence determination unit 54 . When the dew condensation prevention air blowing operation is performed and the exhaust fan 20 is operated, the indoor air RA flows into the drying chamber 13 through the warm air passage 35, and the indoor air RA that has flowed into the air exhaust passage 23 and After passing through the exhaust duct 22 in order, it is discharged to the outdoors O. Then, the temperature of the exhaust duct 22 itself can be raised to substantially the same temperature as or higher than the temperature of the indoor air RA. Therefore, even if the outer surface 22o of the exhaust duct 22 is not covered with a heat insulating material and the indoor air RA contacts the outer surface 22o, the occurrence of dew condensation on the outer surface 22o of the exhaust duct 22 can be appropriately prevented. can be done.

The warm season determining unit 55 is means for determining whether or not it is a warm season in which dew condensation does not occur on the outer surface 22o of the exhaust duct 22, such as summer or intermediate season, using a calendar function or the like.
Then, the dew condensation prevention control unit 56 prohibits execution of the dew condensation prevention air blowing operation when the warm season determination unit 55 determines that it is the warm season. This prevents unnecessary operation of the exhaust fan 20 during the warm season when condensation does not occur on the outer surface 22 o of the exhaust duct 22 .

Furthermore, the dew condensation prevention control unit 56 can execute the dew condensation prevention fan operation described above until the dew condensation generation determination unit 54 no longer determines that dew condensation will occur. Regardless of the results, the dew condensation prevention air blowing operation may be terminated after execution for a certain period of time. In addition, by prohibiting the execution of the dew condensation prevention air blowing operation regardless of the determination result of the dew condensation determination unit 54 until a certain period of time has elapsed from the end of the operation, dew condensation on the outer surface 22o of the exhaust duct 22 is prevented. If the state continues, the dew condensation prevention air blowing operation can be repeatedly executed at regular time intervals to rationally suppress the occurrence of dew condensation.

Further, the dew condensation prevention controller 56 can be configured to operate the hot air generator 30 to supply the hot air HG to the drying chamber 13 so as to perform the dew condensation prevention air blowing operation described above. In this manner, by operating the hot air generating unit 30 and supplying the hot air HG to the drying chamber 13 in the dew condensation prevention air blowing operation, the hot air HG is introduced into the exhaust duct 22 from the drying chamber 13 toward the outdoors O. circulates. As a result, the temperature of the exhaust duct 22 itself can be raised to the inside air temperature Tr or higher, and the occurrence of dew condensation on the outer surface 22o of the exhaust duct 22 can be more reliably prevented. Furthermore, if the dew condensation prevention air blowing operation is executed while operating the hot air generating unit 30 prior to the drying operation, the temperature of the drying chamber 13 can be increased in advance, so that the operation time of the next drying operation (drying time ) is shortened to improve energy saving and usability.

[Another embodiment]
Another embodiment of the present invention will be described. It should be noted that the configuration of each embodiment described below is not limited to being applied alone, and can be applied in combination with the configurations of other embodiments.

(1) In the above-described embodiment, the hot air generator 30 is configured by the burner 31 that burns the fuel gas using the indoor air RA taken in from the indoor room R as the combustion air CA to generate the combustion exhaust gas as the hot air HG. , an electric heater that heats the indoor air RA taken in from the indoor R to generate the heated air as the hot air HG.

(2) In the above embodiment, the drying chamber 13 was described as a space formed inside the rotating drum 12 that rotates around a substantially horizontal rotating shaft. A space formed inside a vertical rotary tank that rotates around a substantially vertical axis of rotation can be used as the drying chamber, or a fixed chamber can be used as the drying chamber.

(3) In the above-described embodiment, the dew condensation generation determination unit 54 indirectly estimates the temperature T23 of the exhaust air passage, the inside air temperature Tr, and the detection result of the wind pressure switch 24. It was determined whether or not dew condensation would occur. For example, dew condensation occurred directly on the outer surface 22o of the exhaust duct 22 based on the detection result of a water leakage sensor attached to the outer surface 22o of the exhaust duct 22. It may be determined whether or not

1 clothes dryer (dryer)
13 drying chamber 13t drying chamber thermistor (drying chamber temperature detector)
20 exhaust fan 22 exhaust duct 22o outer surface 23 exhaust air passage 23t exhaust air passage thermistor (exhaust air passage temperature detector)
24 wind pressure switch (outside air inflow detection part)
30 hot air generator 31 burner (hot air generator)
35 hot air path 35t hot air path thermistor (hot air path temperature detector)
36 Hot air inlet 50 Control unit 51 Operation control unit 53 Inside air temperature detection unit 54 Dew condensation generation determination unit 55 Warm period determination unit 56 Dew condensation prevention control unit A Object to be dried EG Exhaust gas HG Warm air O Outdoor R Indoor RA Indoor air T13 Drying Room temperature T23 Exhaust air passage temperature T35 Warm air passage temperature Tr Inside air temperature

Claims (6)

a drying chamber in which an object to be dried is accommodated and hot air is introduced from a hot air inlet;
a hot air generating unit capable of generating the hot air and supplying it to a hot air path leading to the hot air inlet;
an exhaust air passage installed indoors and connected to an exhaust duct leading to the outdoors;
an exhaust fan that takes in exhaust air from the drying chamber and sends it out to an exhaust air passage;
An operation capable of executing a drying operation of operating the exhaust fan and the hot air generating unit to supply warm air to the drying chamber and exhaust the exhaust air to dry the object to be dried stored in the drying chamber. A drying apparatus comprising a control unit,
a dew condensation determination unit that determines whether dew condensation occurs on the outer surface of the exhaust duct;
and a dew condensation prevention control section that executes a dew condensation prevention air blowing operation for operating the exhaust fan when the dew condensation generation determination section determines that dew condensation occurs on the outer surface of the exhaust duct. an exhaust air passage temperature detection unit that detects the temperature of the exhaust air passage as an exhaust air passage temperature;
an inside air temperature detection unit that detects the temperature of the indoor air as the inside air temperature,
The dew condensation generation determination unit determines that there is a temperature difference equal to or greater than a predetermined set temperature range between the exhaust air passage temperature detected by the exhaust air passage temperature detection unit and the inside air temperature detected by the inside air temperature detection unit. 2. The drying apparatus according to claim 1, wherein it is determined that dew condensation occurs on the outer surface of the exhaust duct in a case where the dew condensation occurs. As the inside air temperature detection unit,
a hot air passage temperature detecting unit for detecting the temperature of the hot air passage when the hot air generating unit is not operating as the inside air temperature; 3. The drying apparatus according to claim 2, comprising at least one of the drying chamber temperature sensing units that sense as temperature. an exhaust air passage temperature detection unit that detects the temperature of the exhaust air passage as an exhaust air passage temperature;
an outside air inflow detection unit that detects the inflow of outside air into the exhaust duct from the outdoors,
The dew condensation occurrence determination unit detects the inflow of outside air into the exhaust duct by the outside air inflow detection unit, and determines that the exhaust air passage temperature detected by the exhaust air passage temperature detection unit is a predetermined set exhaust air passage. 4. The drying apparatus according to any one of claims 1 to 3, wherein it is determined that dew condensation occurs on the outer surface of the exhaust duct when the temperature drops below the temperature. A warm season determination unit that determines whether it is a warm season in which condensation does not occur on the outer surface of the exhaust duct,
The drying apparatus according to any one of claims 1 to 4, wherein the dew condensation prevention control unit prohibits execution of the dew condensation prevention air blowing operation when the warm season determination unit determines that it is the warm season. The drying apparatus according to any one of claims 1 to 5, wherein the dew condensation prevention control section operates the hot air generation section to supply hot air to the drying chamber in the dew condensation prevention air blowing operation.

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