“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 RocksZeolite Pack

Zeolite helps prevent the odours and moisture from attaching to your furnishings too quickly and gives it a chance to work in the air the way it was designed naturally to do.  Adding a Big Bag of Rocks to your bedrooms and living areas will help you control your air quality and save you money in the process.

BUY NOW with Mitey Fresh

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!


Peace Lilies are very common houseplants because they are easy to grow. They can grow up to 30 cm tall, highly desirable supporting fresh air indoors.

BUY NOW online


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.

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

Carol Parr

Author Carol Parr

Carol Parr is a Building Biologist and Healthy Home Wizard. She has worked with asthma and allergy sufferers in their homes and work places for over twenty years, specialising in mould, dust mites, chemicals, EMFs and WiFi. When she’s not turning unhealthy rooms into healthier, relaxing and productive spaces, she’s most likely frightening her husband and their children with numerous “let’s see what this does when …” projects.

More posts by Carol Parr

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