JP6674212B2 - Hot air heater - Google Patents

Description

  The present invention relates to a hot air heater.

  In Patent Document 1, a suction port is provided at a rear portion in a shape in which a cross-sectional area of an upper portion is gradually reduced from a lower portion, a blow-off port is provided at a front portion, and an opening at a narrow angle is provided. A vertical electric hot air blower is disclosed in which a fan motor and a ceramic heater are provided inside a main body formed at a height, and a louver for changing a wind direction is movably provided at an outlet.

  Since the height of the vertical electric heater is almost the height of a person's knees, it is stable and can be warmed efficiently from the feet to the waist to get warmth. By automatically oscillating the head, the abnormal heating of the local part is mitigated.

  Patent Document 2 discloses an electric hot air blower that energizes a ceramic heater and drives a blower fan to blow heat generated in the ceramic heater as hot air. There is disclosed an electric hot air blower that supplies electric power of each of the shifted half-wave waveforms and blows the heat generated at this time as hot air by driving a blower fan at this time.

  According to the electric hot air blower, it is possible to control the amount of electric power to the PTC heater while keeping the air flow of the hot air constant, thereby enabling the temperature control of the hot air.

JP-A-8-334264 JP-A-8-261560

  However, the vertical electric hot air blower disclosed in Patent Literature 1 is configured so that local abnormal heating is reduced by automatically oscillating the louver, The hot air with a small temperature unevenness controlled to an appropriate temperature is not blown from the foot where the user wants to get warm to around the waist.

  Further, the electric hot air blower disclosed in Patent Document 2 can control the temperature of the hot air while controlling the amount of electric power to the PTC heater while keeping the air flow of the hot air constant. The method of controlling the amount of electric power to the heater has been complicated and expensive.

  SUMMARY OF THE INVENTION In view of the above-described conventional problems, an object of the present invention is to provide a simple structure capable of outputting hot air having a uniform temperature and an inexpensive hot air even when temperature unevenness occurs in hot air passing through a heating mechanism. The point is to provide a wind heater.

  In order to achieve the above-mentioned object, a first characteristic configuration of the hot air heater according to the present invention is that, as described in claim 1 of the claims, external air is sucked and blown from a suction port provided in a casing. A blower that blows toward the outlet, a heating mechanism that is provided in a flow path of the air sucked by the blower and heats the air, and air that is blown out of the blowout port through the heating mechanism. And a mixing mechanism for mixing.

  When the outside air sucked by the blower is heated by passing through the heating mechanism, even if temperature unevenness occurs, the air blown from the outlet is mixed and adjusted by the mixing mechanism to have a uniform temperature. Therefore, the user does not feel uncomfortable. In addition, it may be mixed by the mixing mechanism before being blown out from the outlet, may be mixed by the mixing mechanism after being blown out from the outlet, or may be mixed by the mixing mechanism when blown out from the outlet. You may.

  The second characteristic configuration is, as described in claim 2, in addition to the first characteristic configuration, the mixing mechanism guides the air on the end side that has passed through the heating mechanism in a central direction. The point is that it is composed of guide vanes.

  Even when the temperature of the air at the end portion that has passed through the heating mechanism and the temperature of the air at other portions are different, the air at the end portion that has passed through the heating mechanism is guided in the center direction by the guide vanes, and And is blown out from the outlet as warm air adjusted to a uniform temperature. A guide blade that adjusts the flow of air having a non-uniform temperature after heating can output hot air at a uniform temperature with a simple structure and can be configured at low cost.

  The third characteristic configuration is, as described in claim 3, in addition to the above-mentioned second characteristic configuration, a louver in which a plurality of blades are juxtaposed at the outlet is provided, and the guide blade is The present invention is characterized in that it is provided on a slat and configured to guide air passing through the slat.

  When the air heated by the heating mechanism is blown out through the blades, the air is mixed and adjusted to a uniform temperature by the guide blades provided on the blades. By arranging the guide blades within the width of the blade along the hot air blowing direction, the entire device can be made thinner along the hot air blowing direction.

  The fourth characteristic configuration is, as described in the fourth aspect, in addition to the above-mentioned third characteristic configuration, at least a pair of plate-like members arranged so that the guide blades protrude from the surface of the slat. And the gap between the pair of plate-like bodies is gradually narrowed on the downstream side along the flow direction of air.

  The air blown out from the louver is guided by a pair of plate-like bodies provided on the blades and gradually mixed on the narrow downstream side to be adjusted to a uniform temperature and blown out.

  According to a fifth feature configuration, as described in claim 5, in addition to any one of the first to fourth feature configurations, the heating mechanism includes a plurality of heat generating modules that generate heat when energized. In addition, power supply to all the heat generating modules and power supply to at least a part of the heat generating modules can be selectively switched.

  The power consumption can be adjusted by switching the power supply state to the heat generating module. However, when some of the heat generating modules are energized, the air passing through the heat generating modules may have uneven temperature, and if blown out as it is, the user may feel uncomfortable. Even in such a case, warm air adjusted to a uniform temperature by the mixing mechanism described above is blown out.

  According to the sixth characteristic configuration, as described in claim 6, in addition to the fifth characteristic configuration described above, the heat generating modules are provided side by side along the lateral width direction of the air outlet, and the left and right heat generating modules are disposed. The point is that the power supply to the module and the power supply to one of the right and left heat generating modules can be selectively switched.

  In a state in which power is supplied to one of the right and left heat generating modules, the air that has passed through the heated heat generating module becomes heated warm air, whereas the air that has passed through the non-powered heating module remains cool. Even in such a case, hot air adjusted to a uniform temperature in the left-right direction by the mixing mechanism described above is blown.

  As described above, according to the present invention, even when the temperature unevenness occurs in the hot air that has passed through the heating mechanism, it is possible to output a hot air having a uniform temperature with a simple structure and provide an inexpensive hot air heater. Can now be offered.

(A) is a perspective view of a hot air heater according to the present invention, (b) is a front view thereof, and (c) is a rear view thereof. Explanatory drawing of the operation unit of the hot air heater (A) is a front view of a hot air heater, and (b) is a cross-sectional view taken along line AA of (a). (A) is an exploded perspective view of the hot air heater, and (b) is an exploded view of the hot air heater without the operation unit and the legs as viewed from the side. (A) is an exploded perspective view of a heater unit, (b) is an exploded view as viewed from the same side. (A) is an exploded perspective view of the upper heater unit, and (b) is an exploded view as viewed from the same side. (A) is a front view schematically showing a PTC heater in which heating modules are arranged in two rows on the left and right, (b) is a side view thereof, and (c) is a bottom view thereof. Illustration of PTC heater control circuit A perspective view of a louver provided with guide vanes on a slat. (A) is a perspective view of the vane provided with the guide vanes as viewed obliquely from above, (b) is a perspective view of the vane viewed from obliquely below, (c) is a plan view of the same, (d) is a front view of the same, (C) is the same bottom view FIG. 4 is a view for explaining a state in which air passing through a PTC heater to which one of right and left heat generating modules is energized is mixed by a pair of plate-shaped guide blades. FIG. 4 is a view for explaining a state in which air passing through PTC heaters in which heating modules are arranged in four rows on the left and right and energized every other is mixed by two pairs of plate-shaped guide blades.

Hereinafter, an example of the hot air heater 1 constituting the present invention will be described with reference to the drawings.
As shown in FIGS. 1 (a) to 1 (c) and FIGS. 3 (a) and 3 (b), the hot air heater 1 is a tower type having two upper and lower stages, and is provided on a casing 2 and a rear surface of the casing 2. It has two upper and lower suction ports 3 and two upper and lower air outlets 4 similarly provided on the front.

  An upper and lower two-stage blower 5 for sucking outside air from each suction port 3 and blowing the air toward each outlet 4 is provided, and a heating mechanism 6 is provided in a flow path of the air sucked by each blower 5, respectively. The suctioned outside air is heated by the heating mechanism 6 and then discharged from the louvers 70 provided in each outlet 4. Further, the warm air heater 1 is provided with a mixing mechanism 7 (see FIG. 3B) for mixing the air that has passed through the heating mechanism 6. The flow path is a path along the flow of air that is sucked from the suction port 3 and reaches the outlet 4 via the blower 5.

  In other words, the warm air blown out from the upper outlet 4 warms around the waist of the standing worker and around the back of the person performing the sitting work. To warm the feet of the elderly. That is, the upper and lower two-stage tower type in which the whole body is warmed by the warm air from the upper and lower two-stage outlets 4.

  The human sensor 11 is provided on the upper front part of the casing 2. The motion sensor 11 is a sensor configured using an infrared sensor or an ultrasonic sensor. A detection signal from the human sensor 11 is output to a circuit board 12a described later, and the circuit board 12a controls hot air based on the detection signal. Thus, when a person approaches the front of the warm air heater 1, the presence sensor 11 detects the presence of the person and the warm air heater 1 can be automatically turned on. In addition, when the state where the presence of a person is not detected continues for a predetermined time without turning off the hot air heater 1, the hot air heater 1 can be automatically turned off.

An operation unit 12 for operating the hot air heater 1 is provided on an upper surface of the casing 2.
FIG. 2 shows details of the operation buttons of the operation unit 12. A main power button 12f is independently disposed below the center.

  The mode switching button 12b is a button for switching the operation mode. Whether to operate the above-described motion sensor 11 to automatically turn ON / OFF, to operate continuously without operating the motion sensor 11, or to operate in conjunction with the room temperature, The operation mode can be selected by the mode switching button 12b. In the operation mode linked to the room temperature, the room temperature can be set in four stages from a high temperature to a low temperature by the temperature switching button 12c. The warm air heater 1 is provided with a room temperature sensor, and in the operation mode linked to the room temperature, the operation is adjusted so as to reach the set room temperature.

  As shown in FIG. 3B, the hot air heater 1 is provided with upper and lower two-stage PTC heaters 64, which are heating mechanisms 6, and each of the PTC heaters 64 can be controlled independently. ing. Returning to FIG. 2, that is, the upper PTC heater 64 can be selected by the upper heater switching button 12d, and the lower PTC heater 64 can be selected by the lower heater switching button 12e. There are three control modes that can be selected: strong, weak, and off.

  As shown in FIGS. 3A and 3B and FIGS. 4A and 4B, the casing 2 is divided into a front panel 2a and a rear panel 2b. An operation unit 12 is provided on the upper surface of the casing 2, and a circuit board 12 a constituting a control unit is provided below the operation unit 12. A leg 13 is provided on the lower surface side of the casing 2. The leg 13 is substantially disc-shaped and larger than the cross section of the casing 2, so that the effect of preventing a fall due to an earthquake or the like is high.

  The rear panel 2b has two suction ports 3 above and below. A dust filter 2c is attached to the outside of the rear panel 2b so as to cover the suction port 3. The front panel 2a is provided with two outlets 4 vertically. The two upper and lower outlets 4 are respectively provided so as to face the upper and lower two suction ports 3 of the rear panel 2b.

  As already described, the blower 5 and the heater unit 60 are built in the casing 2. Two blowers 5 are provided with axial fans 51, each of which is installed at a position directly opposed to the upper and lower two suction ports 3 on the back side. A heater unit 60 is disposed on the front side of the blower 5 and is attached so as to fit into the outlet 4 of the front panel 2a.

  As a result, the outside air sucked by the blower 5 is sucked into the casing 2 from the suction port 3 after the dust and dirt is removed by the dustproof filter 2c, heated by the heater unit 60, and heated from the outlet 4 It is blown out as wind.

  As shown in FIGS. 5A and 5B, the heater unit 60 is configured by vertically connecting two upper and lower heater units 60a and 60b with a connecting member 60c.

  As shown in FIGS. 6A and 6B, the upper heater unit 60a includes a PTC heater 64, a heater case 6a, a safety mesh 6d, a louver 70 having a guide blade 73 as a mixing mechanism 7, and an outer frame. The body 71 is provided. The lower heater unit 60b has the same configuration.

  The PTC heater 64 is housed in the heater case 6a. A bimetal-type thermostat 6 b is attached to the heater case 6 a so as to control the temperature of the PTC heater 64. A temperature fuse 6c is attached to the heater case 6a, so that when the PTC heater 64 generates abnormal heat, the power supply to the PTC heater 64 is shut off.

  Further, a safety mesh 6d is provided between the louver 70 and the PTC heater 64 in order to prevent a finger from coming into contact with the high-temperature PTC heater 64 through a gap between the louvers 70 of the louver 70.

  In the heater unit 60, the air sucked by the blower 5 (see FIG. 3B) is heated by the PTC heater 64 and then mixed and blown out by the guide blade 73.

  As shown in FIGS. 7A to 7C, the PTC heater 64 is a heater using a PTC thermistor 62 having a property that the resistance value increases with temperature. That is, since the heater itself has the self-temperature control function, the PTC heater 64 is characterized in that it does not consume wasteful power once it has warmed up, and there is little risk of abnormal temperature rise.

  The PTC heater 64 is composed of two heat generating modules 61, and the heat generating modules 61 are arranged in two rows on the left and right along the width direction of the outlet 4 (see FIG. 4A). Each of the heat generating modules 61 includes a PTC thermistor 62, fins 63 disposed in close contact with both sides thereof, and electrode terminals T0 to T2 for supplying electricity to the PTC thermistor 62. The central electrode terminal T0 is a common terminal for the two left and right heat generating modules 61. As the fins 63, in addition to corrugated fins, offset fins, waving fins, and the like are used, and the material thereof is aluminum, copper, or the like having high thermal conductivity.

  The air sucked by the blower 5 (see FIG. 4) passes through the gap between the fins 63 and flows from the back side to the front side of the PTC heater 64. When the PTC thermistor 62 generates heat by energization, the heat is transmitted to the fins 63 on both sides by heat conduction, and the fins 63 are heated. Then, when the air passes through the gap between the fins 63 heated to a high temperature, the air is warmed mainly by heat transfer from the fins 63. In addition, it is preferable to design the fin structure in consideration of the flow rate of air passing through the gap between the fins 63, the pressure loss, the heat transfer coefficient, and the like.

  As shown in FIG. 8, the heat generating modules 61 arranged in two rows on the left and right of the PTC heater 64 switch the left and right switches S1 and S2 based on a signal from the circuit board 12a (see FIG. 4), respectively. Control of energization can be performed independently. For example, when the upper heater switching button 12d of the control unit 2 shown in FIG. 2 is turned off, both the switches S1 and S2 of the two left and right heat generating modules 61 of the PTC heater 64 mounted on the upper heater unit 60a are turned off. Becomes When the upper heater switching button 12d is weakened, one switch S1 of the two left and right heating modules 61 is turned on, the other switch S2 is turned off, and when the upper heater switching button 12d is further strengthened. , Both switches S1 and S2 of the two left and right heat generating modules 61 are turned on. The switches S1 and S2 may be integrally formed in the circuit board 12a.

  That is, the heating mechanism 6 includes a plurality of heat generating modules 61 that generate heat when energized, and is configured such that energization to all the heat generating modules 61 and energization to at least a part of the heat generating modules 61 can be selectively switched. Have been.

  As described above, since the energization of each heat generating module 61 can be controlled independently, the temperature of the air passing through the gap between the fins 63 of each heat generating module 61 can be changed independently. . The same applies to the control of energization of the left and right two heat generating modules 61 of the PTC heater 64 mounted on the lower heater unit 60b by the lower heater switching button 12e.

  When only one of the heating modules 61 arranged in two rows on the left and right is energized, the air passing through the energized heating module 61 is heated, but the air passing through the other non-energized heating module 61 is heated. Since the air is not heated, there is a possibility that a temperature difference occurs in the air blown out from the air outlet 4, which may cause discomfort to the user.

  Therefore, even in such a case, the guide vanes 73 that function as the mixing mechanism 7 that mixes the air that has passed through the heating mechanism are provided so that hot air having a substantially uniform temperature can be blown out.

  As shown in FIGS. 9 and 10 (a) to (e), the louver 70 has a plurality of blades 72 arranged in a vertical direction at substantially equal intervals between two left and right columns 72d (see FIG. 6). It is configured.

  The wing plate 72 has a substantially trapezoidal plate shape, and is disposed such that its long side is perpendicular to the air flow direction. The long side on the downstream side of the air is arc-shaped and protrudes toward the downstream side of the air. At both ends of the long side on the upstream side of the air, there are extending portions 72a extending to the upstream side of the air, and at the tip of each extending portion 72a, a protruding portion 72b protruding outward parallel to the long side is provided. is there.

  A tip 72c is provided at the tip of each projection 72b with a predetermined amount of offset downstream of the air. The protruding portion 72b is engaged with the groove of the outer frame 71 (see FIG. 6), and the blade 72 is free to rotate about an axis passing through the left and right protruding portions 72b. The tip 72c is supported by left and right columns 72d. Therefore, when any one of the blades 72 is rotated about an axis passing through the protruding portion 72b, the supporting column 72d supporting the distal end portion 72c moves up and down, thereby causing other blades arranged in parallel. The plate 72 also rotates in conjunction with the axis passing through the protrusion 72b.

  Thus, the air blowing direction can be adjusted in the vertical direction, and the air blowing flow rate can be adjusted.

  The guide blade 73 is provided on the lower surface side of the slat 72. The guide blade 73 may be formed integrally with the blade 72, or may be configured as a separate member. The guide blades 73 are a pair of plate-like members 74 arranged so as to protrude from the lower surface of the blade 72. The plate-shaped body 74 has a substantially rectangular shape, is in contact with the wing plate 72 at one long side, and is orthogonal to the wing plate 72.

  Then, both ends of the long side of the plate-shaped body 74 are in contact with the long side of the blade 72 on the upstream side of the air and the long side of the blade 72 on the downstream side of the air. The plate-shaped body 74 is formed at an angle to the air flow direction, and is formed so that the gap between the pair of plate-shaped bodies 74 becomes gradually narrower on the downstream side in the air flow direction.

  Thereby, the air that has flowed into the left and right ends of the wing plate 72 is guided in the center direction by the guide blades 73 while passing through the gap between the wing plates 72 arranged side by side. It will be mixed with the incoming air. Note that the angle θ between the above-described air flow direction and the plate-shaped body 74 is preferably 30 to 60 degrees, and more preferably 40 to 50 degrees.

  As shown in FIG. 11, when the left heat generating module 61a of the PTC heater 64 is energized and the right heat generating module 61b is not energized, the air sucked by the blower 5 (see FIG. 4) is used as the PTC heater 64. When passing through, the air passing through the left heat generating module 61a is heated, while the air passing through the right heat generating module 61b is not heated.

  Therefore, the air that has passed through the PTC heater 64 is warm air that has passed through the left heat generating module 61a and has been heated (thick line arrow in the figure), and cold air that has passed through the right heat generating module 61b and has not been heated (in the figure). And a thin line arrow).

  However, after that, the warm air and the cool air are mixed while passing through the vane 72 provided with the guide vanes 73. That is, the flow direction of the warm air that has flowed into the left end portion of the wing plate 72 is changed by the left plate-like body 74 constituting the guide blade 73, and is guided toward the center, that is, the center in the left-right direction.

  On the other hand, the flow direction of the cold air flowing into the right end side of the wing plate 72 is changed by the right plate-like body 74 constituting the guide blade 73, and is similarly guided toward the center. In this way, the warm air and the cool air guided toward the center of the slat 72 are both mixed near the center of the slat 72.

  Then, by mixing the warm air and the cool air evenly, the temperature is controlled to an appropriate temperature, and the air having the reduced temperature unevenness flows out of the louver 70 provided with the guide vanes 73 as the warm air. Will be.

Hereinafter, another embodiment will be described.
As shown in FIG. 12, the PTC heater 64 is provided with the above-described heat generating modules 61 in four rows on the left and right, and the louver 70 is provided with the pair of plate-like bodies 74 on the left and right in two pairs. The guide vanes 73 that are configured side by side may be formed. Each of the heat generating modules 61 of the PTC heater 64 can independently control the energization.

  Here, the heating modules 61 of the PTC heater 64 are controlled so as to be energized every other one. Therefore, the air that has passed through the PTC heater 64 after being sucked by the blower 5 (see FIG. 4) corresponds to warm air (thick line arrow in the figure) or cold air (thin line in the figure) corresponding to the heat generating module 61 that has passed. Arrow).

  As a result, warm air and cool air flow out of the PTC heater 64 alternately on the left and right. Then, the warm air and the cold air that have passed through the left side of the PTC heater 64 are mixed by a pair of left plate members 74 formed on the louver 72 of the louver 70, and the right side of the PTC heater 64. The warm air and the cool air that have passed through are mixed by a pair of right plate-like members 74 formed on the louver 72 of the louver 70. In this way, warm air and cold air are evenly mixed, so that air having an appropriate temperature and small temperature unevenness flows out of the louver 70 provided with the guide vanes 73 as warm air.

  Instead of the PTC heater 64 in which the heat generating modules 61 are arranged left and right as described above, a PTC heater 64 in which the heat generating modules 61 are arranged vertically may be used. Accordingly, the blades 72 of the louver 70 may be arranged in a vertical position and arranged side by side at substantially equal intervals. Also in this case, by forming the guide blade 73 integrally with the wing plate 72, air can be guided toward the center in the up-down direction, and temperature unevenness can be reduced in the same manner as described above.

  Further, when a PTC heater 64 in which a plurality of heat generating modules 61 are arranged is used, the temperature of the hot air may be changed by changing the ratio of the heat generating modules 61 in the ON or OFF state. Furthermore, a temperature gradient can be imparted to the warm air by intentionally forming a region where the number of the heat generating modules 61 in the ON state is large and a region where the heat generating module 61 is small.

  Further, the hot air heater 1 is not limited to the tower type having two upper and lower stages, and the heater unit 60 may have one stage or three or more stages. When there are a plurality of heater units 60, it is preferable that each heater unit 60 can independently control the temperature. This makes it possible to blow warm air having a temperature suitable for each part to the feet, hips, shoulders, head, and the like.

  Further, the guide blade 73 does not necessarily have to be formed integrally with the blade 72 of the louver 70. In other words, the plurality of guide blades 73 may be arranged between the adjacent upper and lower blades 72 so as to be separated from the blades 72, and may be configured to be arranged at substantially equal intervals in the vertical direction. Further, the guide blade 73 may be disposed in a space between the louver 70 and the heating mechanism 6, or the guide blade 73 may be disposed on the opposite side of the heating mechanism 6 with the louver 70 interposed therebetween.

  Further, the guide blade 73 is a pair of plate-like members 74 similar to the above-described pair of plate-like members 74, and the interval between the two plate-like members 74 is smaller than the interval between the pair of plate-like members 74. The plate-like body 74 may be further formed so as to be included inside the pair of plate-like bodies 74 described above. By doing so, the gap between the two pairs of plate-like bodies 74 is formed so as to become gradually narrower on the downstream side along the flow direction of air, so that the mixing of warm air and cool air is further promoted. Will be done.

  Further, the guide blade 73 is not limited to the one formed by the flat plate-shaped body 74, and may be formed by a curved plate-shaped body or a block-shaped one.

  In the above-described embodiment, the example in which the heating mechanism 6 is configured by the PTC heater has been described. However, the heating mechanism 6 may be configured by another heating element or the like other than the PTC heater. It may be configured by a housed sheath heater, a plurality of panel heaters arranged in parallel so as not to hinder the flow of air along the flow path, and the like. Further, in addition to using heat generated from the electric resistor as a heat source, a case where combustion heat of kerosene or gas is used as a heat source may be used.

  The hot air heater described above is only one embodiment of the present invention, and the description is not intended to limit the scope of the present invention. It goes without saying that the shape, size, material and the like can be appropriately changed and designed.

1: Hot air heater 2: Casing 3: Suction port 4: Outlet 5: Blower 51: Axial fan 6: Heating mechanism 60, 60a, 60b: Heater unit 61, 61a, 61b: Heating module 62: PTC thermistor 63 : Fin 64: PTC heater 7: mixing mechanism 70: louver 72: wing plate 73: guide blade 74: plate 11: human sensor 12: operation unit 12 a: circuit board 13: leg

Claims (3)

A blower that sucks outside air from a suction port provided in a casing and blows the air toward an outlet,
A heating mechanism that is provided in the flow path of the air sucked by the blower and heats the air,
A mixing mechanism configured to guide the air on the end portion side that has passed through the heating mechanism toward the center , and a mixing mechanism that mixes the air that has passed through the heating mechanism,
A louver provided at the outlet and having a plurality of blades arranged side by side;
With
The hot air heater is provided on the wing plate and configured to guide air passing through the wing plate .   The guide vane is constituted by at least a pair of plate-like bodies arranged so as to protrude from the surface of the blade, and a gap between the pair of plate-like bodies is gradually narrowed on a downstream side along a flow direction of air. The hot air heater according to claim 1, wherein Before SL heating mechanism is configured with a plurality of heat generating modules for generating heat by energization,
Juxtaposed prior SL direction exothermic module along the wing plate of the louver, and energization to all the heating modules, and a power supply to the at least a portion of the heat generating modules are selectively switchable configured The hot air heater according to claim 1 .

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