What Are The Settings On A Dehumidifier?

Dehumidifiers typically have a set of controls on the top or side of the unit, often in the form of pressable buttons, that allows you to turn on and adjust all of the functions offered by the appliance.

The settings available on a dehumidifier will differ between make and model but there’ll be a few settings that can be universal among all dehumidifiers because they’re all designed to undertake one main job and remove moisture from the air.

The main settings on a dehumidifier typically include the power button, humidity control, mode selector, fan speed, timer and tank full indicator. Some dehumidifiers may also have settings that control other features such as UV light or Ionizer for further air purification.

Our own dehumidifier has the following settings:

  • Power on button with tank full indicator light
  • Fan speed (3 settings)
  • Mode selector (heater, dehumidifier, smart & air purifier)
  • Fan oscillation
  • Timer
  • Plasma Ionizer
  • UV Light
  • Up & Down button for humidity control
Dehumidifier Controls
The array of settings available to us on the top of our dehumidifier

All of these settings on a dehumidifier serve a purpose to help keep your room at the healthy humidity you want.

Read on to find out how the settings on your dehumidifier work to keep the appliance working properly.

How A Dehumidifier Works

A dehumidifier can work in the same way as an air conditioner (for refrigerant types).

A fan in the dehumidifier draws in warm, wet air. The air immediately hits a set of condenser coils, which are filled with refrigerant, making them cold. The cold temperature draws the moisture out of the air and makes it condense on the coil droplets at a time.

Warm air can hold more moisture than cold air can. As the air that enters the dehumidifier cools, the water is squeezed out of it, leaving it on the coils.

For desiccant models of dehumidifier, absorbent chemicals such as silica gel are used to extract moisture from the air flowing through.

Dehumidifier Plugged In
Our dehumidifier is the desiccant type

The water is then collected in a tank, often found at the base of the unit.

Whichever type of dehumidifiers is being used, the two main settings on all humidifiers, no matter how complicated or simple, are humidity control and the tank full indicator.

Humidity Control

The humidity control on a dehumidifier sets the target humidity you want for the air in your home.

This humidity will be displayed in a percentage, and dehumidifiers will use a built-in humidistat to measure the ongoing current humidity and ensure the moisture level reaches its target.

The most common settings are for humidity control on a dehumidifier include:

  • The % setting
  • The + and – setting
  • The fan speed setting
  • The timer setting
  • The sleep setting

You should tailor your dehumidifier’s humidity settings to your environment. Different environments will require different levels of humidity control.

The % Setting

The % setting is the percentage of humidity that you want your dehumidifier to keep once the dehumidifier has brought the humidity down to that level.

This is connected to the relative humidity sensor, which detects the relative humidity (RH) of the air surrounding it so that it can decide how long to run. They usually range from 30 to 80 percent.

Relative humidity, or RH, is the humidity relative to the total amount of water that air can hold.

The maximum amount that air can hold is 99 percent. At 100 percent humidity, the water has no choice but to leave the air. It naturally does this in the form of rain.

Warm air holds more moisture than cold, so it tends to be much wetter. Moist air is a breeding ground for dust mites, mold, and other allergens. Getting the air to a recommended humidity level in your home or work environment not only makes things more comfortable but also makes you and those around you healthier.

The current (and proposed) humidity levels are shown in a simple display on our dehumidifier.

The current humidity being displayed

The + and – Settings

The + and – settings raise or lower the percentage of humidity on your dehumidifier sensor.

The + sign, sometimes a > sign, will raise the humidity level, where the – or < sign will lower it.

For our dehumidifier, it has up and down arrows that we can use to change our desired humidity level (in 5% increments) down to a minimum of 35%

Dehumidifier Controls
Up and down arrows to change the desired humidity

The recommended healthy humidity for a room is between 30 and 50 percent, with up to 60% being acceptable.

It’s not recommended that you set it above 70 percent, due to the proclivity of mold to grow in wet environments. Mold growing in your indoor environment, whether it be work or home, can cause irritation of the eyes, skin, and lungs.

The Fan Speed Setting

The fan speed setting lets you regulate how fast or slow you would like the fan to be spinning inside the dehumidifier.

The rate of speed of the fan determines how quickly the immediate area is dehumidified.

The fan moves air through the dehumidifier. It draws the wet air in at the cold condenser coils, as explained before. The act of taking the moisture out of the air only takes a moment, before the fan moves the now drier air out of the appliance.

Our dehumidifier has three fan speeds:

  • Sleep (low)
  • Normal (medium)
  • Turbo (high)
Dehumidifier Fan Speed Control
Fan speed settings

A faster-moving fan does not always necessarily mean that the air will dehumidify faster, however.

In fact, it can mean the opposite. The air being sucked in by the fan might not have enough time around the condenser coils to have the water taken out of it, so it is simply blown out of the dehumidifier much like it went in.

The fan on a slower setting can make the air drier, faster. The draws in less air and moves it more slowly, but this allows it to hang around the condenser coils longer. Since it is able to get colder, more water is extracted from the air and gathered on the coils before the air is moved out of the dehumidifier by the airflow of the fan.

However, we find that the fastest fan speed (turbo) works very well with our desiccant type of dehumidifier.

The Timer Setting

The timer setting is often depicted as a clock or an hourglass.

Dehumidifier Timer Control
Timer button for time settings

This allows you to set the dehumidifier on a timer so that it can run when you wish.

If you live in an area where it is particularly wet during a certain part of the day, you can time the machine to turn on at that time. Or alternatively, you can time it to turn off during times when the air is relatively dry.

The Sleep Setting

The sleep setting, should your dehumidifier have one, is closely linked to the timer setting. It allows you to put your machine to sleep at certain times, so it can run or not run for long periods.

Dehumidifiers can be loud, especially when in a small, enclosed space. The sleep setting allows it to still work without disturbing the people in the room.

The lowest fan speed on our dehumidifier is references as ‘Sleep’.

Our dehumidifier also has a ‘Smart’ mode that brings the humidity of our home down to 50% and alters performance based on the current humidity.

Dehumidifier Mode Control
Our dehumidifier running in smart mode

When at 50%, the dehumidifier runs quietly in sleep mode until the humidity rises back up again.

Tank Full

The next setting that all dehumidifiers have is the tank full setting. This indicates whether the water tank is full or not.

Dehumidifying the air is, literally, taking the moisture out of the air and so it has to go somewhere. The moisture pulled from the air it collected in a water tank.

The light on our dehumidifier indicating the water tank is full

When the water gathers on the condenser coils a droplet at a time, the droplets grow until they are too heavy to stay on the metal coil. They then drip off, just like a raindrop.

They drip into the tank, and when the tank is full, the settings let you know and automatically keep the dehumidifier from running until the tank is emptied.

Other Dehumidifier Settings

Power On

The power button on a dehumidifier can be used to turn the appliance on and off.

Dehumidifier Power Control
The power button

The tank full indicator light also forms part of the power button assembly on our dehumidifier.


Certain models of dehumidifier, such as ours, can have features found on different appliances, such as being able to be a heater or an air purifier.

The mode button on our dehumidifier cycles through these different mode settings.


The oscillation setting on a dehumidifier can adjust the air outlet direction, and whether you want it to oscillate between the two or more direction settings.

Dehumidifier Fan Oscillation Button
Fan oscillation settings

Plasma Ionizer

Our dehumidifier features a built-in Ionizer that we can use to help provide further purification of the air in our home by helping to ‘kill off viruses, dust mites, mold and other airborne allergens’.

Dehumidifier Plasma Ionizer Control
Plasma Ionizer button

UV Light

The UV light feature on our dehumidifier also provides further air purification by helping to ‘destroy germs and bacteria’.

Dehumidifier UV Light Control
UV light button

What Are The Settings On A Dehumidifier?

Dehumidifiers typically share a common set of settings between all makes and models, including power on, humidity control, fan speed and timer.

Other settings found on a dehumidifier can include being able to cycle through different modes and features for increased air purification.

Further Reading

Does A Dehumidifier Actually Work?

Do Dehumidifiers Need To Be Emptied?

Do Dehumidifiers Lose Effectiveness?