Heat pump dryers can often be used to dry a variety of different types of fruit, including guava. To dry guava, you can follow these steps:

1. Cutting: Thinly slice the guava to make it easier to dry.
2. Pretreatment: Soak guava flakes in hot water for a few minutes to kill bacteria and microbes that may be present and help reduce drying time.
3. Set the drying temperature: The temperature setting of the heat pump dryer should be determined according to the specific model, and can usually be set on the control panel of the machine. For guava drying, it is recommended to set the temperature between 60 and 65 degrees Celsius to preserve its quality and taste.
4. Drying: Evenly distribute the processed guava slices on the baking tray of the heat pump dryer, and then start the machine for drying. Time and drying results vary by dryer type and the thickness of the guava, and usually take several hours or longer.
5. Confirm the drying degree: During the drying process, the drying degree of the guava should be checked regularly. Drying is complete when the flakes are dry and brittle. It can be placed in a well-ventilated place to cool after drying.

In general, guava drying temperatures should be set between 60 and 65 degrees Celsius, depending on the model and size of your heat pump dryer. At the same time, during the drying process, the degree of drying of the guava should be checked regularly, and ensure that it is completely dried and stored after cooling.