PROCEDURES FOR IMPLEMENTING A HYGIENE PROGRAM

Description

[0001] The invention relates to a method for carrying out a hygiene program for a laundry treatment appliance and a laundry treatment appliance with a control device.

[0002] Laundry treatment appliances, such as heat pump dryers, can have an additional electric heater in addition to a heat pump to warm the laundry.

[0003] CN 111 279 028 A discloses a method for sterilizing laundry in a drum dryer. In the final phase of the drying process, the air is heated to an elevated temperature and conveyed through the drum. The temperature is measured at various points in the process air duct using sensors, and the temperature is regulated accordingly based on the measured values.

[0004] The invention aims to provide an improved method for implementing a hygiene program for a laundry treatment appliance and an improved laundry treatment appliance with a control device. According to the invention, this object is achieved by a method for implementing a hygiene program for a laundry treatment appliance and a laundry treatment appliance with a control device having the features of the main claims. Advantageous embodiments and further developments of the invention are set out in the following subclaims.

[0005] The advantages achievable with the invention are a high reduction in germs during a hygiene program.

[0006] A method for implementing a hygiene program for a laundry treatment appliance is presented. The laundry treatment appliance comprises a drum for holding laundry, a pump unit for pumping atomized water into the drum, a heat pump for tempering the process air, a heating unit for heating the process air, a process air blower for conveying the process air through a circuit out of the drum and through the heat pump and the heating unit back into the drum, a temperature sensor for providing a temperature signal representing a temperature in the drum, a humidity sensor for providing a humidity signal representing an air humidity in the drum, and a control device for controlling the hygiene program. The method comprises the following steps: Outputting a pump signal to an interface to the pump unit to cause water, which is atomized in a spray head, to be pumped into the drum, outputting a switch-on signal to an interface to the heat pump to cause the process air to be heated, outputting a heating signal to an interface to the heating unit to cause the process air to be heated, outputting a process air signal to an interface to the process air blower to convey the process air through the circuit, outputting a switch-off signal to the interface to the heat pump to switch off the heat pump when the temperature signal represents a predetermined hygienic temperature, and outputting a pump switch-off signal to the pump unit to switch off the pump unit when the humidity signal represents a predetermined hygienic air humidity.

[0007] A laundry treatment appliance can be understood as an appliance in which laundry, for example textiles, can be treated. For example, this can be a washing machine, a washer-dryer, or a tumble dryer. The treatment of laundry can be understood as washing or drying, or as carrying out the hygiene program described here. During operation of the laundry treatment appliance, the laundry can be arranged in a laundry treatment chamber formed by the drum and treated using process air. A heat pump can be understood as a known device in which components are functionally connected to one another in order to heat and dehumidify the process air flowing through it. For example, the process air can first flow through an evaporator and then a condenser. A refrigerant can be arranged or can be arranged in a refrigerant circuit of the heat pump.The refrigerant can be evaporated in the evaporator using moist process air and condensed in the condenser using the dehumidified process air. A compressor and a throttle can also be arranged in the refrigerant circuit. Thus, the heat pump device can be used to take in the moist process air, for example from a laundry treatment room, cool it and dry it, reheat it, and release it again. In addition, the laundry treatment appliance comprises a heating unit, which can be operated electrically, for example, and is designed to heat the process air independently of the heat pump. For example, the process air, driven by the process air fan, can flow in a circuit through both the heat pump and the heating unit and be heated either by the heat pump or by the heating unit, or by both simultaneously.The switching on and off of the heat pump and heating unit can be controlled using the control device. The heated air can then be used to heat the drum of the laundry treatment appliance and thus the laundry arranged in the drum, for example during the hygiene program. The hygiene program can be used, for example, to hygienically process laundry that has already been washed and at least partially dried. This can be advantageous, for example, if laundry is not removed from the washing machine immediately after a wash cycle, but is left in the closed drum for a while, for example, several hours. In such or a similar case, the laundry can be moistened and heated using the method presented here in order to reduce any germs that have developed.For example, increased air humidity or relative humidity of up to 85% and simultaneously increased temperatures of up to 75°C can contribute to germ reduction. Humidity can be achieved by spraying atomized water into the drum. Atomized water can be defined as water in droplet form. Depending on the spray device used, these droplets can have a larger or smaller diameter. Smaller droplets can help achieve the desired air humidity more quickly.For this purpose, in the process presented here, after a heating phase in which the process air is heated by both the heating unit and the heat pump, the heat pump can be switched off. The desired hygiene temperature can be maintained solely by the heating unit during the hygiene phase following the heating phase until the end of the hygiene program. During the program, the process air can be heated significantly and high humidity can be generated. Under these conditions, germs can be actively reduced. Optimal conditions regarding temperature and humidity can be created by operating the electric heater and switching off the heat pump.

[0008] According to one embodiment, the step of outputting the pump signal can occur before the steps of outputting the switch-on signal and the heating signal. For example, in a first step, the pump can be switched on to moisten the dry laundry at the beginning of the hygiene program with finely atomized water, which can, for example, be pumped from a condensate tank and sprayed into the drum. The process air can then be heated so that the water in the drum can evaporate. Advantageously, a combination of increased humidity and increased temperature enables optimal conditions for germ reduction.

[0009] According to a further embodiment, the step of outputting the pump signal can occur after the steps of outputting the switch-on signal and the heating signal. For example, the process air and the laundry arranged with it in the drum can be heated to a predetermined temperature before it can be humidified by the pump as a result of the pump signal. This has the advantage that the laundry absorbs less water during the subsequent humidification. This allows the air humidity to be kept higher and less water is required. For example, cotton at a temperature of 20°C and a relative humidity of, for example, 65% can have a residual moisture content of 0%. At the same ambient temperatures and when heated to a higher temperature, such as 53°C or 85°C, cotton can have a residual moisture content of up to -3%, which can result in the laundry being overdried, so to speak.In contrast, cotton can have a residual moisture content of 3% at a temperature of 20°C and a relative humidity of, for example, 80%. At the same ambient temperatures and when heated to a higher temperature, such as 53°C, cotton can have a residual moisture content of 1%, and when heated to 85°C, a residual moisture content of -1%. At a relative humidity of, for example, 95% and when heated to a temperature of 20°C, cotton can have a residual moisture content of over 10%. At the same ambient temperatures and when heated to a higher temperature, such as 53°C or 85°C, cotton can have a residual moisture content of between 4 and 6%. Consequently, heating the laundry before moistening it can reduce water absorption in the laundry.

[0010] In addition, the pump signal can be output if the temperature signal represents a predetermined preheating temperature. For example, the preheating temperature can correspond to the hygiene temperature. For example, the laundry in the drum can be heated to a specific temperature, such as 65°C. Subsequent moistening of the laundry can cause the temperature inside the drum to drop slightly, allowing it to be heated again to the predetermined hygiene temperature in the subsequent step of outputting the switch-on signal. This advantageously allows temperature and humidity to be optimally coordinated, thus saving water.

[0011] According to a further embodiment, the method can comprise a step of outputting a reversing signal to an interface to a drive of the drum in order to bring about a reversing state of the drum. For example, the drum of the laundry treatment appliance can be designed as a reversing drum, whereby a rotation process in two directions can advantageously be possible. In this case, for example, a drive of the drum can bring about a change in the direction of rotation. Such a reversing state can be implemented, for example, in response to the reversing signal. Using a reversing drum, for example, the moistening of the laundry can be carried out in the reversing state in order to advantageously achieve optimal moistening of the laundry.

[0012] According to a further embodiment, the predetermined hygiene temperature value can be at least 60°C. For example, the control device can use the temperature signal to continuously compare the current temperature in the drum with a stored temperature reference value to determine whether the desired hygiene temperature, for example, 65°C, has been reached. Germs can advantageously be reduced when heating to temperatures above 60°C.

[0013] In addition, the predetermined hygiene humidity level can be at least 60%. For example, the control device can use the humidity signal to continuously compare the current humidity in the drum with a stored humidity reference value to determine whether the desired hygiene humidity, for example, 65%, has been reached. Germs can advantageously be reduced at a humidity level above 60%.

[0014] According to a further embodiment, the method can comprise a step of terminating the hygiene program after a predetermined period of time, following the step of outputting the shutdown signal. For example, the control device can comprise a counter that can count down a predetermined period of time, for example, 30 minutes, as a result of the step of outputting the shutdown signal and additionally or alternatively as a result of the step of outputting the pump shutdown signal. During this period, both the hygienic temperature and the hygienic humidity in the drum can be maintained. Advantageously, the hygiene program can be terminated automatically after the expiration of the period of time.

[0015] According to a further embodiment, the step of outputting the switch-on signal can be repeated after the step of outputting the switch-off signal if the temperature signal represents a predetermined threshold temperature. For example, after a heating-up phase in which the heating unit and the heat pump are operated simultaneously, the heat pump can be switched off in the step of outputting the switch-off signal. Subsequently, the heating output required for the hygiene program can be generated largely via the heating unit, which can also be referred to as auxiliary heating. Under these circumstances, however, the heat pump's compressor can be damaged due to its low heat level. To prevent this, for example, a drop in temperature to a predetermined threshold can be detected by means of the temperature sensor, and the heat pump can be restarted when this threshold temperature is reached.This has the advantage that components within the heat pump, such as the compressor, can be protected while the hygiene program is being carried out.

[0016] Although the approach described is based on a household appliance, the method described here can be used accordingly in connection with a commercial or professional device, for example a medical device such as a cleaning or disinfection device.

[0017] The approach presented here further provides a device designed to perform, control, or implement the steps of a variant of a method presented here in corresponding devices. This embodiment of the invention in the form of a device also allows the problem underlying the invention to be solved quickly and efficiently.

[0018] The device can be designed to read in input signals and to determine and provide output signals using the input signals. An input signal can, for example, represent a sensor signal that can be read in via an input interface of the device. An output signal can represent a control signal or a data signal that can be provided at an output interface of the device. The device can be designed to determine the output signals using a processing rule implemented in hardware or software. For example, the device can comprise a logic circuit, an integrated circuit, or a software module and can, for example, be implemented as a discrete component or be comprised of a discrete component.

[0019] In addition, a laundry treatment appliance for treating laundry using a hygiene program with a variant of the previously presented control device is presented. The laundry treatment appliance has the following features: a drum for holding laundry, the drum being designed to perform a reversible rotation process, a pump unit for pumping atomized water into the drum, a heat pump for tempering process air, a heating unit for heating process air, a process air blower for conveying the process air through a circuit out of the drum, through the heat pump and the heating unit back into the drum, a temperature sensor for providing a temperature signal representing a temperature in the drum, and a humidity sensor for providing a humidity signal representing an air humidity in the drum.

[0020] Advantageously, the previously presented method for carrying out a hygiene program can be optimally implemented in such a laundry treatment appliance.

[0021] According to one embodiment, the laundry treatment appliance may comprise a condenser tank for collecting water condensed in the heat pump, wherein the pump unit may be configured to pump the water out of the condenser tank. Advantageously, the condensed water can be fed back into the appliance circuit, thereby saving water overall.

[0022] Also advantageous is a computer program product or computer program with program code that can be stored on a machine-readable carrier or storage medium such as a semiconductor memory, a hard disk memory, or an optical memory. If the program product or program is executed on a computer or device, the program product or program can be used to carry out, implement, and / or control the steps of the method according to one of the embodiments described above.

[0023] An embodiment of the invention is shown purely schematically in the drawings and is described in more detail below. It shows Figure 1 shows a schematic representation of a laundry treatment appliance according to an embodiment; Figure 2 shows a flowchart of an embodiment of a method for carrying out a hygiene program for a laundry treatment appliance; Figure 3 shows a flowchart of an embodiment of a heating phase of the method; Figure 4 shows a flowchart of an embodiment of a heating phase of the method; and Figure 5 shows a flowchart of an embodiment of a method for carrying out a hygiene program for a laundry treatment appliance.

[0024] Figure 1shows a schematic representation of a laundry treatment appliance 100 according to an exemplary embodiment. The laundry treatment appliance 100 comprises a drum 105 for holding laundry, which is designed, merely by way of example, as a reversing drum in order to circulate the laundry in a reversing state in two different rotation directions by means of a drive 107. Furthermore, the laundry treatment appliance 100 comprises a pump unit 110 for pumping atomized water into the drum 105, with which water laundry arranged in the drum can be moistened. The pump unit 110 can be controlled, for example, by a control device 115. In this exemplary embodiment, the control device 115 is designed both to put the drum 105 into the reversing state using a reversing signal 117 and to output a pump signal 120 to an interface to the pump unit 110 in order to pump atomized water into the drum 105.For example only, the pump unit 110 is configured to draw water from a condenser tank 125 for pumping. The humidity generated in this or another manner in the drum 105 can be detected by a humidity sensor 130. The humidity sensor 130 is configured to provide a humidity signal 135 representing the humidity to the control device 115. Using the humidity signal 135, the control device 115 is configured to output a pump shutdown signal 140 to the pump unit 110 in order to shut down the pump unit 110 when the humidity signal 105 represents a humidity corresponding to a predetermined hygiene humidity value.

[0025] In this exemplary embodiment, water can be pumped into the condensate tank 125 by a condensate pump 145 after it has condensed in the circuit of a heat pump 150. The heat pump 150 is designed to regulate the temperature of the process air within the laundry treatment appliance 100 and, for this purpose, comprises, merely by way of example, an evaporator 152, a compressor 154, a condenser 156, and a throttle 158. For example, the heat pump 150 can be controlled by the control device 115. By outputting a switch-on signal 160 from the control device 115 to the heat pump 150, the heat pump can be switched on to heat the process air. In addition, the control device 115 is designed to switch off the heat pump 150 by outputting a switch-off signal 162 when a predetermined hygiene temperature is reached in the drum 105.The current temperature in the drum 105 can be detected by a temperature sensor 165, which is designed to provide a temperature signal 167 representing the temperature to the control device 115.

[0026] In addition to the heat pump 150, the laundry treatment appliance 100 in this exemplary embodiment comprises a heating unit 170 designed to heat the process air. For this purpose, the heating unit 170 can be controlled by the control device 115 using a heating signal 175. Thus, both the heat pump 150 and the heating unit 170 are designed to heat the process air. In this exemplary embodiment, a process air blower 180 is designed to convey the process air into the drum 105 and from the drum 105 in a circuit through a filter 182, the heat pump 150 and the heating unit 170 back into the drum 105. In this exemplary embodiment, the process air blower 180 can also be controlled by the control device 115 using a process air signal 185.Thus, the control device 115 is designed to control the execution of a hygiene program for the hygienic processing of laundry by controlling the individual components of the laundry treatment appliance 100.

[0027] Figure 2 shows a flowchart of an embodiment of a method 200 for carrying out a hygiene program for a laundry treatment appliance, as described in the previous figure.

[0028] The method 200 comprises a step 205 of outputting a pump signal to an interface to the pump unit of the laundry treatment appliance in order to pump atomized water into the drum. At the beginning of the hygiene program, the dry laundry arranged in the drum is moistened with water pumped from the condensate container and sprayed into the drum. Using a suitable spray device, the water can be sprayed into the drum in the form of finely atomized water. To achieve optimal moistening of the laundry, moistening of the laundry should only be carried out when the drum is in reverse. Otherwise, the volume flow generated by the process air blower would ensure that the atomized water is directed into the appliance's filters and not into the laundry.

[0029] In this exemplary embodiment, step 205 of outputting the pump signal is followed by a step 210 of outputting a switch-on signal to an interface to the heat pump in order to heat the process air. Furthermore, the method 200 comprises a step 215 of outputting a heating signal to an interface to the heating unit in order to heat the process air. For this purpose, the process air is conveyed through a circuit out of the drum, through the heat pump and the heating unit, and back into the drum. To convey the process air through the circuit, a process air signal is output to an interface to a process air blower in a step 220 of outputting.

[0030] According to alternative embodiments, steps 205, 210, 215, 220 are performed simultaneously at the beginning of the heating phase or sequentially in a suitable order. According to one embodiment, step 205 is performed after steps 210, 215 or after at least one of steps 210, 215. In this case, the laundry is first preheated by pumping the process air through the circuit and the active heat pump and / or the active heating unit. After such preheating to a predetermined preheating temperature or for a predetermined preheating period, the laundry is moistened by spraying water into the drum from the pump unit.

[0031] The process air is thus heated, causing water in the drum to evaporate. This is achieved by the heating unit, which can also be referred to as an auxiliary electric heater. For the hygiene program, a target temperature of, for example, just over 65°C and an air humidity of, for example, just over 65% in the drum are to be achieved by moistening the dry laundry and simultaneously heating the process air via the auxiliary electric heater and the heat pump. By operating the auxiliary heater and the heat pump simultaneously in this exemplary embodiment, the heating phase is significantly shortened compared to heating using only one of the two components.

[0032] As soon as the temperature signal represents a temperature corresponding to a predetermined hygiene temperature value, a shutdown signal is output to the interface of the heat pump in step 225 of outputting the shutdown signal to shut down the heat pump. For example only, the predetermined hygiene temperature value in this exemplary embodiment corresponds to the target temperature of 65°C. In another exemplary embodiment, the hygiene temperature value can also correspond, for example, to a temperature of 62°C or 70°C, but advantageously to at least 60°C. With step 225 of outputting the shutdown signal, the heat pump is shut down and the heating phase of the hygiene program is ended.Following this step, in this example, the process air is heated exclusively by the heating unit for the remainder of the hygiene program, since the maximum temperature and maximum relative humidity are higher when the auxiliary heater is used exclusively in the preheated state. Therefore, both components should be operated during the preheating phase to heat the system as quickly as possible. Once the system is heated, the heating output should be generated entirely or largely by the auxiliary heater.

[0033] For example, the heat pump can be permanently switched off during the execution of a hygiene phase of the hygiene program following the heating phase or can only be operated for a short time, for example to prevent damage to the heat pump.

[0034] The method 200 further includes a step 230 of outputting a pump shutdown signal to the pump unit to shut down the pump unit when the humidity signal represents a humidity corresponding to a predetermined hygienic humidity value. For example only, the predetermined hygienic humidity value in this embodiment corresponds to a humidity of 65%. In another embodiment, the hygienic humidity value may also correspond, for example, to a humidity of 62% or 70%, but advantageously at least 60%.

[0035] Figure 3 shows a flow chart of an embodiment of a heating phase 300 of the method as described in the previous Figure 2 The heating phase 300 shown here corresponds to the heating phase described in the previous Figure 2The process described above comprises step 205 of outputting a pump signal, followed by steps 210, 215 of outputting a switch-on signal and a heating signal. In other words, in this process variant, dry laundry 310 is directly remoistened with water 315, and subsequent heating generates the temperature and humidity necessary for germ reduction. As a result, the water 315 evaporates and is separated from the laundry 310 again.

[0036] Figure 4 shows a flow chart of an embodiment of a heating phase 300 of the method as described in the previous Figure 2was described. In the method variant presented here, the laundry is heated before humidification. This means that step 205 of outputting the pump signal is only carried out after steps 210, 215 of outputting the switch-on signal and the heating signal, wherein the pump signal is output when the temperature signal represents a predetermined preheating temperature. Subsequently, in this embodiment, steps 210, 215 of outputting the switch-on signal and the heating signal are repeatedly carried out after the laundry has been humidified. In other words, in the heating phase 300 of the method, dry laundry is first heated, then humidified, and then heated again. As a result, the air humidity is kept higher and less water is required than in the previous Figure 2 and 3 illustrated embodiment.

[0037] Figure 5shows a flowchart of an embodiment of a method 200 for carrying out a hygiene program for a laundry treatment appliance, as described in the previous Figure 1 The method 200 presented here corresponds to or is similar to that described in Figure 2described method, with the difference that additional steps are shown. Thus, in the first step 500, the hygiene program is started by outputting a start signal. By way of example only, the start of the hygiene program can be initiated manually, for example by a user, for example when the laundry treatment appliance is switched on and the control device of the laundry treatment appliance receives a corresponding user signal to start the hygiene program. In this exemplary embodiment, a step 505 of outputting a reversing signal follows in order to put the drum of the laundry treatment appliance into a reversing state. By way of example only, step 505 of outputting a reversing signal is followed by a decision step 510 in which a decision is made as to whether preheating of the laundry is to be carried out. If preheating of the laundry is not desired, step 205 of outputting the pump signal follows directly.If the laundry is to be preheated, steps 210, 215 of the.

[0038] The switch-on signal and the heating signal are output directly afterwards. As a result, the laundry is heated while still dry, for example, until the temperature signal represents a predetermined preheating temperature. For this purpose, in a comparison step 515, the temperature in the drum is compared, for example, with a stored reference value of 65°C. As long as the preheating temperature is not reached, the dry laundry continues to be heated. When the preheating temperature is reached, step 205 of outputting the pump signal is then carried out in order to moisten the laundry. Subsequently, steps 210, 215 of outputting the switch-on signal and the heating signal are carried out, possibly again, in order to heat the now damp laundry by means of the heat pump and the heating unit to a temperature corresponding to a predetermined hygiene temperature value.In step 520 of the testing, the temperature is checked using the temperature sensor. As long as the hygiene temperature of, for example, 65°C has not yet been reached, the laundry continues to be heated by the heating unit and the heat pump. When the hygiene temperature value is reached, step 225 follows, in which a shutdown signal is output to switch off the heat pump. Following this step, the heat pump is switched off, and the temperature in the drum of the laundry treatment appliance is regulated solely by the heating unit. To protect the components in the heat pump, however, in this exemplary embodiment, step 210 of outputting the switch-on signal is repeatedly executed after step 225 of outputting the shutdown signal if the temperature signal represents a predetermined threshold temperature.Accordingly, throughout the course of the hygiene program, the heat pump is briefly switched on and off again, while the heating unit heats continuously. In this exemplary embodiment, the execution of the hygiene program is checked in a counting step 525 using a counter, so that the hygiene program is terminated only after a predetermined period of time in a step 530 where an end signal is output.

Claims

1. Method (200) for carrying out a hygiene program for a laundry treatment appliance (100), wherein the laundry treatment appliance (100) comprises a drum (105) for receiving laundry (310), a pump unit (110) for pumping nebulised water (315) into the drum (105), a heat pump (150) for controlling the temperature of process air, a heating unit (170) for heating the process air, a process air blower (180) for conveying the process air through a circuit out of the drum (105) and through the heat pump (150) and the heating unit (170) and back into the drum (105), a temperature sensor (165) for providing a temperature signal (167) representing a temperature in the drum (105), a humidity sensor (130) for providing a humidity signal (135) representing an air humidity in the drum (105) and a control device (115) for controlling the hygiene program, and wherein the method (200) comprises the following steps: outputting (205) a pumping signal (120) to an interface with the pump unit (110) in order to cause pumping of nebulised water (315) into the drum (105); outputting (210) a switch-on signal (160) to an interface with the heat pump (150) in order to cause warming of the process air; outputting (215) a heating signal (175) to an interface with the heating unit (170) in order to cause heating of the process air; outputting (220) a process air signal (185) to an interface with the process air blower (180) in order to pump the process air through the circuit; outputting (225) a switch-off signal (162) to the interface with the heat pump (150) in order to switch the heat pump (150) off when the temperature signal (167) represents a temperature corresponding to a predetermined hygiene temperature value; and outputting (230) a pump switch-off signal (140) to the pump unit (110) in order to switch the pump unit (110) off when the humidity signal (135) represents a humidity corresponding to a predetermined hygiene humidity value.

2. Method (200) according to claim 1, wherein the step (205) of outputting the pumping signal (120) occurs before the steps (210, 215) of outputting the switch-on signal (160) and the heating signal (175).

3. Method (200) according to claim 1, wherein the step (205) of outputting the pumping signal (120) occurs after the steps (210, 215) of outputting the switch-on signal (160) and the heating signal (175).

4. Method (200) according to claim 3, wherein the pumping signal (120) is output when the temperature signal (167) represents a predetermined preheat temperature.

5. Method (200) according to any of the preceding claims, comprising a step (505) of outputting a reversing signal (117) to an interface with a drive (107) of the drum (105) in order to cause a reversing state of the drum (105).

6. Method (200) according to any of the preceding claims, wherein the predetermined hygiene temperature value is at least 60°C.

7. Method (200) according to any of the preceding claims, wherein the predetermined hygiene humidity value is at least 60%.

8. Method (200) according to any of the preceding claims, comprising a step (530) of terminating the hygiene program after a predetermined period of time, after the step (225) of outputting the switch-off signal (162).

9. Method (200) according to any of the preceding claims, wherein the step (210) of outputting the switch-on signal (160) is performed repeatedly after the step (225) of outputting the switch-off signal (162) if the temperature signal (167) represents a predetermined threshold temperature.

10. Laundry treatment appliance (100) for treating laundry (310) by means of a hygiene program with a control device (115) which is designed to carry out and / or control the steps (205, 210, 215, 220, 225, 230) of the method (200) according to any of the preceding claims in corresponding units, wherein the laundry treatment appliance (100) has the following features: a drum (105) for receiving laundry (310), the drum (105) being designed to perform a reversible rotation operation; a pump unit (110) for pumping nebulised water (315) into the drum (105); a heat pump (150) for controlling the temperature of process air; a heating unit (170) for heating process air; a process air blower (180) for conveying the process air through a circuit out of the drum (105), through the heat pump (150) and the heating unit (170) and back into the drum (105); a temperature sensor (165) for providing a temperature signal (167) representing a temperature in the drum (105); and a humidity sensor (130) for providing a humidity signal (135) representing a humidity in the drum (105).

11. Laundry treatment appliance (100) according to claim 10, comprising a condenser tank for receiving water (315) condensed in the heat pump (150), wherein the pump unit (110) is designed to pump the water (315) out of the condenser tank (125).

12. Computer program product comprising program code for carrying out the method (200) according to any of claims 1 to 9 when the computer program product is run on a control device (115) in a laundry treatment appliance (100) according to any of claims 10 or 11.