How long should a Dehumidifier run per Day?

One of the biggest questions that often crops up among consumers is how long should a dehumidifier run per day. Well, there is no single answer for this question, because there are several factors that come into play including the level of humidity in the surrounding area.

You already know what a dehumidifier is, but just in case there’s any confusion with regards to its functionality, the primary goal of a dehumidifier is to remove excess moisture and lower the relative humidity (RH) in your space.

What is Relative Humidity (RH)?

There are several ways to measure humidity, of which relative humidity is the most common. Humidity and relative humidity are not to be confused with each other, because the former is vaporized water contained in the air, whereas the latter is the total of the current temperature and the amount of vaporized water.

Relative humidity is one of the most important factors to consider when determining the indoor quality of your home. It is generally measured as a percentage, and to keep humans comfortable must be between 20 and 60 percent.

You will experience better indoor air quality if the RH level is kept below 50 percent in the summer, and 30 to 40 percent during the winter. Maintaining the aforementioned numbers will prevent several environmental issues such as condensation, bacteria, mildew, mold, volatile organic compounds (VOCs) and dust mite infestations.

If you have no clue what the RH levels are in your house, you can use a hygrometer commonly referred to a damp meter to get an accurate reading of the RH levels, which will be different across rooms.

As an example, areas such as your kitchen will have a higher RH reading due to the appliances in it including a dishwasher, kettle and stove than the bathroom.

How does a Dehumidifier Work?

Dehumidifiers are classified as household appliances that are engineered to remove the excess moisture from the surrounding air, resulting in living conditions that do not encourage mold, and other allergenic organisms.

It works by sucking in the hot air through an air intake vent, removing the moisture and then blowing it out again via another air outlet.

The moisture that is removed during the above process drips into the onsite capture tank, which you have to empty when filled. Some of the best dehumidifiers are appointed with an LED display that indicates both the current temperature and relative humidity level, saving you the trouble to buy one separately.

How long should a Dehumidifier run for?

Given that the size and dampness varies across rooms, there is no set period of time you should run the dehumidifier for, but here are some general guidelines. A new house for the most part will display a higher RH reading, so it makes sense to run the humidifier in each room continuously until the RH level is below the 60 percent mark.

Once the RH level is normal, you can then experiment with the different settings during different times of the day until you find out how long you should leave the unit running per day.

Given that most modern dehumidifiers come with an auto-shutoff function, you could practically just leave the appliance running around the clock, and just get back to it when the water reservoir is full. This however may result in higher energy costs, sometimes totaling to more than the initial price of the dehumidifier.

If you’re worried about a surge in energy bills, you may want to opt for a dehumidifier that allows you to set the desired humidity level and shuts off automatically when that is reached.

How to Control the Runtime of a Dehumidifier?

Running your dehumidifier 24/7 when it is not required will put an extra burden on its components such as the compressor, which will result in a shorter service life. If you do find that the appliance is going into overtime often, it is highly recommended that you take care of the root cause of the excess humidity.

Removing the source of excess moisture – Each dehumidifier is designed to work in a certain amount of space, which should be a closed environment with the doors and windows tightly shut. If you do have leaky windows and doors from where outside air is able to seep through, try applying door and window seals to the openings to block the intrusion. Bathrooms generally collect more moisture during hot baths and showers, and the best way to let the moisture filled air out is with an exhaust fan.

Preventive Measures – Since most if not all manufacturer instructions vary, it is important that you refer to the owner’s manual that came with your dehumidifier and adjust its settings accordingly. Make sure that the water tank is emptied often, and the integrated vents are cleaned of debris and dust them gently with a soft brush.

All in all, there are no ground rules on how long a dehumidifier should run for per day, because it may run non-stop or not all depending on the moisture level in your space.

3 thoughts on “How long should a Dehumidifier run per Day?”

    • Hi Rodney,

      Thanks for the comment. It is difficult to say for sure, so do make sure to consult the owners manual.

      What make and model did you buy? Does it have an auto shutoff function? Also, do you have a damp meter (hygrometer) or do you know the RH level in the room? Plus whats the size of the room? Sorry more questions than answers.

      If necessary, I run appliances such as Dehumidifiers and Air Purifiers continuously while I am at home, but I do switch them off or set them on auto shutoff if I am leaving the house. I know plenty of people run dehumidifiers constantly, especially at the outset. You might want to check out another post

      Are you happy with the results so far?


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