How Long Should I Run My Dehumidifier?

“How long should I run my dehumidifier every day?” This is an excellent question. I get asked by everyone, whether they’ve had a dehumidifier for years or just started using one.

The best answer would be to run your dehumidifier unit 24 hours a day. However, that could end up costing quite a bit of money, and more than you really need to spend.

The Extraction Rate

The idea is to run all the air through the unit as much as possible. This is called your Extraction Rate, and it’s pretty difficult to determine. An average unit in your space, if it was operating correctly, should extract the moisture to around 50 to 55% Relative Humidity.

With this assumption, you can safely run your dehumidifier for about 12 hours a day. That should (again, depending on your unit) run all the humid air in your space through the system at least once. I usually tell people to run their dehumidifier for 10-12 hours a day, and of course, the more the better.

What About Costs?

If you’re concerned about spending too much on your electricity bill, you can try calling your energy company and asking about the “best times.” Usually, the best times to run your unit, that will save you money, is between 10 pm and 7 am — this is when less people are consuming energy, which drives down the rates.

However, if you’re drying your room, you need to have your unit running, and I doubt you’ll be doing this activity in the middle of the night. So it’s okay if you run your dehumidifier during normal hours from a couple of days to as long as required.

You could also split these times. For instance, you could run for six hours during the day and six hours at night. This is perfectly fine, however, you’ll want to get a timer to help you regulate this.

A timer is useful. Simply attach one to your power point and connect your dehumidifier. Especially great for if you’re running out the door to do errands, drying laundry indoors, or drying a painted wall.

The RH Factor

The ideal Relative Humidity or RH in a building is around 40% to 50%. Given that mould starts to grow at around 65% RH,  it is recommended that your home’s RH level stays well within ideal. Your dehumidifier is used to maintain that RH level.

A household produces 15 litres of moisture per day, bathing, cooking, washing, drying, breathing, sweating … However, properties vary in size, number of occupants, building materials, air flow, circulation, contents, occupant behaviour so there is no set limit about how long to run a dehumidifier.

When you first operate your dehumidifier, it would be good practise to run it continuously until the RH falls below the 60% mark or fills up the water tank, which ever comes first.  Once RH is below 60% you can then use the dehumidifier during day and off during the night.

If the RH has risen, the unit keeps working to bring the RH down and goes into sleep mode when the healthy RH level is reached.

You COULD Invest in Zeolite

If you have variable humidity spaces you can run a system for 24 hours a day without spending as much money as a standard dehumidifier. You can run at nominal costs when you’re just drying and freshening and consistent levels when you’re adding a permanent unit.

If cost is a consideration, I highly suggest you look into buying zeolite for any spaces that need a little something. They are the best bet for keeping your space dry and fresh and saving you money at the same time. I highly recommend them.


Zeolite- Bag of Rocks

Eliminates moisture, damp and musty smells safely and naturally from any wardrobe or room. Reduce mould, mildew, dampness, condensation, odours. 

Zeolite Rocks

Or You COULD Invest In A Dampp Chaser

If value for money is important, I highly suggest you look into buying a Dammp Chaser for spaces that need more than expected. They are the BEST in keeping small spaces consistently dry and fresh. I more than highly recommend them


Dampp Chaser

Eliminates mould, mildew, stagnant air in wardrobes and cupboards, pantries, linen closets, RV’s, boats, rental storage, basements. 

How Long To Run Your Dehumidifier?

So to recap, run your dehumidifier unit for at least 12 hours a day. This is a good rule of thumb. Again, it’s okay if you don’t stick to this schedule every day, but be aware that the more your family runs your dehumidifier unit the fresher and cleaner it will be all year long.

If you have any questions about running your dehumidifier, you can ask in the comments below and I will answer them quickly


Hire a Dehumidifier

Round the clock protection when you need it most! Reduce mould, mildew, dampness, condensation, odours. Relieve hayfever, sinus headache, influenza, sneezing, itchy eyes, stuffy nose, coughing, allergic rhinitis, asthma symptoms any time of year!

Dehumidifier 20 Litre

Towards healthier living Carol Parr ♥

As Building Biologists, we have acquired knowledge of adverse health effects and recommend effective strategies to reduce occupants’ exposure by eliminating and controlling as many sources of pollutants in order to create healthy indoor living environments that are as exposure-free and natural as practically possible.

We cut out all the fluff and confusion of indoor air maintenance and stripped it down to the bare bones.


  • Carol Parr

    We’re glad you’re here. We’re Carol and Tony, founders of one of the longest running Healthy Home Blogs in the world, Mitey Fresh Australia. We’ve been on this journey for the last 25 years and are passionate about helping families sift through health hazards and triggers like allergens, mould, water damage, chemicals and EMFs, to get clarity about what’s toxic and what’s not so they can create a healthy and happy home for their family they love. Each month, people visit this blog seeking focus on the health and wellbeing of their loved ones, sustainable and effective practice tips and guides, to help create and manage healthier indoor spaces, improve the built environment that is pleasing to the senses and support healthy living and nature, every day. Starting this blog was to help change people’s lives, one family at a time, and we can’t wait to share how its allowed us to stand next to you and show you how interpreting these synergies between buildings and the environment they are built in will impact upon the health and well-being of those who occupy them. Find out more about Healthy Homes and what this blog can do for you!

19 thoughts on “How Long Should I Run My Dehumidifier?”

  1. What is the average setting for
    Dehumidifier? we wake up in morning to find all our windows
    Covered with water on the inside
    and our GE machine has collected
    No water. Got any ideas for us

    1. Yes I do! I am unfamiliar with the brand however as a general overview – 1. the machine may be faulty. Check the machine over – clean filter; clean holding container; clean any inlets; motor will be encased for safety; ring GE for maintenance team feedback; motor may be operating inadequately even though you may hear the fan operating. 2. Relative Humidity Setting may be too high – set to 50-55% Relative Humidity, comfortable setting. 3. The machine capacity my be inadequate for the size of the room – we found 16 litre unit most suitable for bedroom, lounge/dining sized room. 4. Type of dehumidifier – a. Refrigerant dehumidifier operates efficiently (21-32 degrees celcius). b. Conventional refrigerant dehum operates efficiently at air above 55% gpp, the warmer and the wetter, the better! c. Low grain refrigerant dehumidifier dries air at a lower dew point 34-40 gpp. d. Desiccant dehum efficient below 30 gpp. Does that help?

  2. Josephine Bentley

    hi Carol.
    I have a new dehumidifier and have just started running it 24/7 as it’s keeping the under the stoop area dry and clean.
    The stoop is well ventilated.

    Which months will the unit be the MOST expensive to run?

    Any advise re; settings, etc?

    i am in NJ.


    1. Hi, I should think the high humidity months since then you’ll have to run the unit more hours than when the humidity is relatively low. Where I come from, the humidity is highest from June through August. That is when my dehumidifier has to run for several hours a day to prevent the development of mold colonies in my indoor spaces.

      1. Thank you for your feedback Patrick. Every space is different and so are the climates. working hand in hand, you will find a happy medium.

  3. We run 2 humidifiers in our basement. They are full everyday. My daughters bedroom is down there so we worry about keeping the humidy down. I was wondering how do you know when to stop using them? Do they just no longer collect water? Can you take too much out of the air?

    1. Hi Deb, Running a dehumidifier, they are full as a response to a damp environment where the machines are located. The basement is sub ground, that is the space is below the ground level and adjacent to earth, soil and rocks, inadequate light and airing. Moisture ingress potentially dampens the building envelope and foundations, keeping building materials damp in this space, it has nowhere to go except into the materials and air.
      The dehumidifier is most beneficial and doing its job, removing that moisture and drying the space.
      To stop using the dehumidifier is when the collection container is dry, for several days, the machine will actually switch off, until of course, when it detects there is moisture in the air.
      Hope that helps 🙂

      1. Hi, I’m in sw fla. and just got a dehumidifier and it was so loud.. but after moving it around, I finally figured it out.. it was the little hose door on side of unit- when shut it made loud noise so I keep it open what a big difference in the noise. Hopefully this will help everyone who has a loud noise. Angie

  4. I’m thinking of putting a timer on my humidifier but the owners Manuel cautions that you should operate the unit by switching off or on the power. Says it may cause shock or fire due to heat generation. Unit is a keystone KSTAD70C. Thank you

    1. Thanks for getting in touch. My advice would be to check the specs on your timer and follow their recommendations. All the best!

  5. My dehumidifier has to be changed often, like every 12 hours its full. I’ve had mold, mildew and dust issues in my apartment for years and it has affected my health, now I have a dehumidifier it is accumulating a lot of water. I still seem the mold in my apartment but it is getting a little better. what does that mean when it fills up fast everyday.

    1. Hello Anika,

      Sounds like there is a lots of moisture in your home. Do you live in a basement apartment? Moisture is very dense and it will usually be in lower levels of homes. If it fills up fast every day, how big is your dehumidifier? Where do you put it usually? Check your walls and for leakage in the bathroom. All these are a factor.

  6. I have been using my dehumidifier for almost 2 months at 12 hours a day approximately..
    I empty the bucket twice a day and clean the filter every couple days..
    tonight it started making a very loud humming sound which is unusual and I don’t know why…
    Am I ruining it by using it so much

    1. Hi Kathy, awesome monitoring of the environment. The humming sound may be that the machine is reverberating. simply shift it, to see if that helps. You are running the machine just fine.

  7. Sticky&uncomfortable

    I just moved into a rental home that was built on a concrete slab, and holy crap there’s a lot of moisture in the air! I was given a used 70L dehumidifier and the humidity control seems to be broken, so it will only run on continuous mode. My home is approximately 900sq ft and I have to empty it every 6-8 hours. It’s seems the “bucket full” alarm isn’t working properly either so I really have to keep an eye on it or I’ll have to attach a hose for continuous draining. I’m very low-income and all utilities in the house are electric so I’m very weary of my 1st electric bill. With soooo much moisture, is it still possible to receive any benefit from running it 12 hrs/day, or is the moisture building right back up while it’s off? I also bought a bunch of packets of what my boyfriend calls some kind of volcanic rock? It looks exactly like the product you have linked to purchase in this article. How many of them would do you recommend for a 900 sq ft home? Thank you so much for this post, it’s been VERY helpful!!!

  8. Della J Buckley

    I am having a problem with the noise coming from the dehumidifier in my basement. The noise comes up from the basement intermittently. The machine runs for 27minutes and shuts off 14 minutes. The dehumidifier does this 24 hours a day. It disturb my rest at night and continues to awaken me throughout the night. What can be done about the noise and does the machine needs to be replaced? Thanks!

    1. Hi Della, thank you for asking. I am umfamiliar with your home’s basement environment, so lets go through a general checklist to get you started. You may already have considered these options or may be of interest. I’ve divided the questions into 2 parts to make it a little clearer.
      – basement space from floor to walls and ceiling may reverberate the noise, like the noise travels through the materials so it would be an idea to place the machine on something that is noise absorbent like cardboard or a piece of timber sheeting.
      – the dehum is a machine and in conjunction with the basement being quite hollow in space, the noise may potentially echo upstairs.

      Timing of on and off
      – the switching of timing im unsure about – is the power supply on a timer?
      – the dehumidifier will reach the set humidity, the unit will switch off. And as the humidity increases, the machine will swith on.
      For example: if the machine is set at 60% RH, and the environment is above this 60% setting, the machine is running. If the humidity in the environment is drier, below 60%, the machine will switch off.
      – in saying this, check what the setting is set at. There is no ideal setting for a basement however I would recommend setting the dehumidifier at 50 to 60% and monitor the switching off and on response.
      Hope this helps.

  9. Lost my Frigidaire manual, doe’s Auto. mean when the temp. setting is reached the unit will turn off and come back on when humidity goes up??

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