Portable dehumidifiers for houses can produce varying noise levels depending on the model, age, and condition of the unit. In recent times, advances in technology allowed manufacturers to design quieter models. A portable dehumidifier with a noise level of fewer than 50 decibels is considered a silent machine.
The noise level of a portable dehumidifier can also depend on its location and surroundings. For example, noise can get amplified if you place the unit in a small, enclosed space, such as a closet or bathroom. Conversely, installing the dehumidification system in a big, open space can reduce noise. Secondly, the unit's mode of operation and settings play an essential role in its operating sound. It is obvious that units sent at high fan speed will produce more noise than at a low-speed stage.
In short, choose a portable clean room dehumidifier with a noise level of not more than 50 DBA. Reading online customer reviews on e-commerce websites will give you honest feedback.