How Long Should You Run an Air Purifier?

Running your air purifier 24/7 is ideal . A room can become recontaminated within 2-4 hours if you leave it off. But how long should you run an air purifier if you’re often out of the house or if you’re always in the house?

Most studies and air purifier manufacturers insist on running your commercial air purifier all day. But..

  • Are you worried about the cost on your bill if you run your fresh air machine too long in a day?
  • Are there any safety issues if you leave your house while the air sanitizer machine is still on?

In this post, you’re going to find out how long you should run an air purifier and the safety, cost and air quality acquainted to it.

How Long Should You Run an Air Purifier?
How Long Should You Run an Air Purifier?

How Long to Run an Air Purifier – Short Answer

You should run your air purifier 24 hours a day . The reason for this is that the air can become recontaminated with dust, allergens or pollen almost instantly.

how long to run an air purifier
Source: Old Almanac

I know, I know, you wouldn’t want to waste away on electric bills or degrade early on its useful life. But portable air purifiers are smartly designed to operate continuously and some even have Energy Star ratings to conserve on electricity.

In the next section, we’ll show you how energy efficient an air purifier can be.

Does the Air Purifier Use a Lot of Electricity?

The fact of the matter is, air purifiers conserve a bulk of electricity . We’ll tell you why.

Does the Air Purifier Use a Lot of Electricity
Does the Air Purifier Use a Lot of Electricity

Air cleaning machines have a maximum power consumption of 40W to 200W for its highest fan speed setting . When you choose to run it at the lower speeds , which most of us do, it will only consume 10W to 30W .

To visualize this, think of the light bulb you use at home. Light bulbs consume 60W. Your laptop typically consumes 50W, while a refrigerator is about 150 watts. And these devices usually run all day long. Running your commercial air sanitizer machine consumes less energy than these machines.

Typical Household Appliances

Average Wattage


150 Watts

light bulb

60 Watts


50 Watts

Air Purifier

40 Watts

Hence, air purifiers are more energy efficient than these appliances and it’s not going to affect your bill enormously.

How Much Does It Cost to Run an Air Purifier All Day?

Typically, air purifiers average between $4 to $15 a month on your electric bill.

Below, we explain how to get the real monthly cost or running an air purifier all day. And let’s compare with your other appliances’ consumption.

Typically, what you can see in your bill is the kilowatt-hour consumption of your electric device. So let’s take the air purifier power consumption. As mentioned, an air cleaning machine for home usually takes 10W to 30W on its lowest setting and 40W to 200W on its highest setting in one (1) hour.

Let’s take a look at HisoAir’s HA128 Air Purifier with a power consumption of 45W or 0.045KW.

Running it all day means switching it on for 24 hours for 30 days in a month .

To get the monthly power consumption, we do this:

Monthly power consumption (KW-hr) = air purifier wattage x 24 hours x 30 days

For this example, we get 0.045W x 24hours x 30days = 32.4 KW-hour

Electricity costs average around 13.11 cents per kilowatt-hour.

To get the monthly cost for an air purifier running 24/7, we do this:

Monthly Electric Cost ($) = Monthly Power Consumption x Cost per KW-Hr

For the example above, we get 32.4 KW-hour x 13.11 cents per kilowatt-hour = $4.2 per month .

How about for your refrigerator running 24 hours a day ? Applying the same principle, your fridge’s monthly electric cost is: 0.150W x 24 hours x 30 days x 13.11 cents per kw-hr = $14.15 per month!

See the difference? So why worry about your air cleaning machine running all day when you can get more healthy and pay only a fraction of the cost?

Ways to Conserve on Air Purifier Electricity (if you’re super thrifty)

Tip #1 Schedule the Fan Speed ​​Modes

Schedule the Fan Speed ​​Modes 4 different speeds for alen unit
Schedule the Fan Speed ​​Modes 4 different speeds for alen unit

Air disinfection machines are designed with smart sensors and can run on auto mode to reduce fan power whenever the room is tidy. This way, it won’t put much pressure on the bill. You can schedule it to run at high speeds only at limited hours in a day if you’re being thrifty.

Nevertheless, it’s a matter of choosing a good brand so you won’t worry about running it all day. So selecting a good quality air clean air machine for home would do better in the long run, even with a higher initial cost.

For that, we recommend the HisoAir brand , offered in small to large air purifier units. If you’re on budget but still want a high performance HEPA air purifier , this will cover you.

Tip #2 Run It at Low Speed ​​If You’re Not Home

Run your air cleaning machine at Low Speed ​​If You're Not Home
Run your air cleaning machine at Low Speed ​​If You’re Not Home

Turn it to its lowest setting if you’re not home or if you have indoor plants.

Tip #3 Vary the Speed ​​Settings According to the Time of the Year

Vary the Speed ​​Settings According to the Time of the Year
Vary the Speed ​​Settings According to the Time of the Year

Adjust the speed setting according to the time of the year. For example, during summers, there is lots of dust and pollen, so you can run your air purifier at higher speeds than in winter.

How Often to Run an Air Purifier at Full Speed?

running an air purifier at full speed
running an air purifier at full speed

Source: Pinterest

To better optimize its performance, only turn it on at full speed when you’re at home. Then you can set it back to low speed whenever you’re going out.

It’s okay not to run the air cleaner machine for home at full speed all day long while optimizing its full performance. This brings us to the next question: How long does it take an air purifier to clean a room anyway?

How Long Does It Take An Air Purifier to Clean A Room?

In short, most air purifiers take 30 minutes to 2 hours to sanitize the air in your room. In just 20 minutes, there should be a noticeable difference in the air quality in your room.

For you to determine how long it takes for your air dust filter machine to purify the room, you should know your room size and the Clean Air Delivery Rate (CADR) of your air purifier. This is to know the air changes per hour (ACH ) the air purifier can perform. The ACH is the number of times a certain volume of air can be cleaned from the room in an hour.

For instance, a home air sanitizer machine has a CADR of 400 CFM and you have a 176 square feet room size. This means the air ionizer machine is running at 4 ACH or cleans the air 4 times in an hour (15 minutes per charge) .

Your weather, humidity and location can also play a role in how fast the commercial air sanitizer machine works. There are more dusts during summer which means it will take longer for the air purifier to clean the air.

Is It Safe to Leave an Air Purifier On All Day?

Yes, it is alright to leave the air purifier on 24/7 to maintain a clean indoor air environment. The only downside to this is that the electric consumption will be a little higher. However, air purifiers do not use a lot of electricity which means it doesn’t put much cost on your bill.

Remember that dust can easily contaminate the air. So if you choose to turn off your dust purifier machine to save a little on electric costs, this would leave your home as dirty as before you turn it on.

Should I Sleep With an Air Purifier On?

should you sleep with an air purifier still on
should you sleep with an air purifier still on

Yes, you should turn your air cleaner machine on in your bedroom, especially if you suffer from asthma, allergies or other respiratory illnesses.

This is because each time you turn off your air purifier, air can become immediately polluted in just 15 minutes.

A study conducted by the Smart Air Filters showed how air can become 50% polluted in just 15 minutes. At 80 minutes, air can become 100% polluted.

graph showing how long does it take for a room to get dusty again after turning off air purifier
graph showing how long does it take for a room to get dusty again after turning off air purifier

So when you turn off your air purifier while sleeping, you will end up breathing unclean air.

Wrapping Up

We hope this article helped you understand how long you should run your air purifier and how little can you spend running it 24/7.

If you want to know the top air purifier manufacturers in China, we’ve written a separate article for this. 5 Best Air Purifier Manufacturers in China (2021).

HisoAir is an air purifier supplier in China offering ODM/OEM services. We have a large variety of air purifiers for homes, industries, hospitals and hotels. Check out our other recommendations for air purifiers or you can contact us if you want a quotation for wholesale air purifiers.

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