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How Long Do I Run My Air Purifier?

“How long do I run my air purifier for?” or “Do I leave the air purifier on overnight?” These are questions I get asked by both residential and commercial occupants, whether they’ve started using an air purifier first time or had one for operating on and off for longer.

24 hours a day would be the most optimal answer would be to operate your air purifier. However, that could cost 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 air to around 6 air changes every hour.

With this assumption, you can safely run your air purifier for about 12 hours a day. That should (again, depending on your unit) run all the air in your space through the filter system at least 72 times. I usually advice people to run their air purifier for 10-12 hours a day, in the spaces that they sleep, work and play.

What About Costs?

If you’re concerned about spending too much on your electric bill, call your energy company and ask about “off peak times.” Usually, the best times to run your unit, that will save you money, is between 9:00pm and 9:00am — less people consume energy, and in turn lowers the tariffs.

However, if you’re filtering the air in your room, you need to have your unit running, and when you need it most, you’d be doing this activity during the day when you are at home or at work. So it’s okay if you run your air purifier during normal hours from a couple of days to as long as required.

You could also split these times. For instance, you could run the air purifier 1-2 hours before you go to bed and 1-2 hours after you have woken up when you are working or 1-2 hours whilst relaxing. This is perfectly fine, however, you’ll want to get a timer to help you regulate this.

You COULD Invest in:


If you have variable air borne triggers like dust, ambient pollution, car fumes you can run a system for 24 hours a day without spending as much money as a standard air purifier. You can run at nominal costs when you’ve adjusted the speed to comfortable, consistent levels when you are looking for quality indoor air.

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 adverse air borne trigger free 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

Mechanical Ventilation System

If year round comfort is important, I highly suggest you look into buying a ventilation system for spaces that need more air flow, circulation and extraction than expected. They are great to keep small and large spaces consistently fresh. I more than highly recommend them.


If value for money is important, I highly suggest you look into buying 10 – 15 indoor plants for spaces that can do with more natural removal of toxins. They are the BEST to keep small spaces consistently dry and fresh. I more than highly recommend them. BONUS


Find some great indoor plant options at your local garden centre- these are a selection that we recommend you look out for.

BONUS – if ambience, humidity balance and prevention of dust in small rooms is important, may I recommend you look into adding a Himilayan salt lamp for spaces that are stagnant, located next to computers and just need that something natural without the maintenance. They are great to keep small spaces and offices consistently dry. BONUS PLUS!

How Long To Run Your Air Purifier?

So to recap, run your air purifier 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 you run your air purifier the fresher and cleaner it will be all year long.

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

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.

Our passion comes from pure necessity that we can all live natural and healthy lives, we can all contribute to human wellbeing and preservation and determine the future health of our children and their environment tomorrow.

As a result of working with us, families thrive, sensitive occupants heal. They’re healthier, they’re alert, they’re happier, more relaxed, more productive, and enjoying life.

Together we bring about healthy indoor environments and create rooms that provide calmness, healthy sleep, relaxation and restored energy for you and your family.

By maintaining indoor spaces to close as possible more natural conditions, occupants are healthy and happy, it’s nice that it sustains our planet’s ecology, you’d agree.


Gale, R.W. Walter, L.C. Alvarez, D.A. Huckins, J.N. Petty, J.D. Robertson, G.L., 2009. “Semivolatile Organic Compounds in Residential Air along the Arizona−Mexico Border”, Environmental Science and Technology., 2009, 43 (9), pp 3054–3060 (Online). Available: [15 April, 2015]

Asthma and Allergy Foundation of America, 2005, “Air Pollution”, (Online), Available: [15 April, 2015]

Wolverton, Dr B.C. 1996, How to Grow Fresh Air: 50 Houseplants that Purify Your Home or Office, Weidenfeld & Nicholson, London.


  • 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!

7 thoughts on “How Long Do I Run My Air Purifier?”

  1. Thanks a lot to you for share. Really this is very informative and useful. that filtering the air can indeed help to remove harmful particles from indoor spaces, particularly allergens, smoke, and mold.

  2. My family always has allergies, so we’ve needed an air purifier since before our kids were born! The best part about these machines is that they don’t just filter out allergens; they also keep your home clean by removing odors and pollutants from the air.
    This is a very informative guide to help you understand how long your air purifier should run and if it needs replacing. It’s also great for those who have just bought an air purifier and are unsure of when they need to change the filter. Thank you for this beautiful guide.

    1. Thank you Evan for popping in and sharing your experiences. What I’m reading is that an air purifier does so much much more than we first read about it, so many benefits.

  3. Hi Carol,

    You suggested running an air purifier usually up to 12h daily, but is that enough? I believe, when you turn off the air purifier, the air could get polluted again (very fast), especially if there is a source of pollution inside. So, switching it off is not always an acceptable option.

    Also, you suggested leaving an air purifier in hours when the energy is the least expensive. I wouldn’t agree with you, because air purifiers usually aren’t huge energy consumers, and the purpose of having an air purifier is to clean the air, not necessarily to save on energy consumption.

    Thanks for the inspiring article!

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