You usually have 3 dehumidifier fan speed settings: low, medium, and high. With 3 options, it’s only natural to wonder if you should run your dehumidifier on low, medium, or high. In many cases, we just want to set the ‘High’ setting right away but this is not always ideal.
Here’s the point of using a dehumidifier (and an explanation of how to think about low, medium, and high settings):
You should get the relative humidity levels down to 30% – 50% interval. That’s pretty much it. In general, all – low, medium, and high – settings should remove enough moisture from the air to lower the humidity levels to below 50%.
In most situation, using a medium dehumidifier setting is most advantageous. However, in certain situations:
- It’s better to use a high dehumidifier setting than a low dehumidifier setting. This is when we have very high relative humidity levels (80% or more) and would like to reduce humidity levels fast. We have such situations mostly during the summer (when the humidity levels spike).
- It’s better to use a dehumidifier low setting vs. high setting. This is usually when we use a dehumidifier with an air conditioner. Every AC unit also works as a dehumidifier. When AC and dehumidifier work in tandem, lowering the dehumidifier setting to ‘Low’ will likely increase the overall energy efficiency of dehumidification (lower combined AC and dehumidifier running costs).

In most situations, however, it is recommended to use a dehumidifier on the medium setting. Here’s why:
What Setting Should I Put My Dehumidifier On? (Medium)
Putting a dehumidifier on low or high setting has its disadvantages.
Disadvantages of using a dehumidifier on high setting include:
- Increased wear-and-tear. If you run a dehumidifier at a 100% dehumidification rate constantly, you will effectively reduce its lifespan. The increased wear-and-tear shortens the lifespan of all HVAC devices, including dehumidifiers.
- Higher running costs (lower efficiency). On a high setting, a 1,000-watt dehumidifier will spend 1 kWh worth of electricity per hour. Yes, it will remove more water, but in general, running a dehumidifier on a high setting (100% dehumidification capacity) is less energy efficient than running it on a low or medium setting.
- Excessive if used with an air conditioner. As we have explained in this post, a dehumidifier and air conditioner can run at the same time. Since AC also reduces relative indoor humidity levels, setting a dehumidifier on high setting while also using a dehumidifier is a bit of an overkill.
Running a dehumidifier on a low setting is also not ideal in many cases. Here is why:
- Low dehumidifier setting might not provide you with a sufficient dehumidification rate to reduce the relative moisture levels below 50%. You will at least have to increase the setting to medium or even high.
- If you can run a dehumidifier on a low setting and you get below 50% humidity levels, this may indicate that you have an oversized dehumidifier. Bigger dehumidifiers are more expensive and take more space; you should consult this how big a dehumidifier do I need article in order to avoid getting a dehumidifier that’s unnecessarily too big.
Considering the disadvantages of low and high dehumidifier setting, the medium setting should be just right.
A medium dehumidifier setting should:
- Adequately reduce the humidity levels below 50%.
- Reach the set humidity setting is the optimal time (high setting will do it fast, low setting might not reach the set humidity at all).
- Have optimal energy efficiency. Running a dehumidifier at a low setting is generally more energy-efficient than running it on a high setting; the medium setting strikes a good balance between energy efficiency and dehumidification rate.
Here’s a simple bottom line:
When you are deciding to put a dehumidifier on a low, medium, or high setting, always start with the medium setting.
If you are satisfied with how fast the medium setting reduces indoor humidity levels, just leave it on ‘Medium’.
If you see that humidity levels stay above 50% on the medium setting, switch to the high setting.
If you see that the medium dehumidifier setting can easily and quickly reduce the moisture levels below 50%, switch to the low setting.
We hope this helps you choose an optimal setting for your dehumidifier.