How Long Should an Air Purifier Work (24/7 or Not)

If you’ve just started using an air purifier, you’ve probably wondered how long you should keep it on, in addition to the many questions that come to mind regarding air purifier usage. It’s not strange at all. Believe me, I get asked this question every now and then, and it seems that this is the most significant misunderstanding from most air purifier users.

Whether you are a beginner or a long-time air purifier user, you should always look at how to get the most out of your air purifier. You should always look at how to use it in the best way. That’s why you need additional training, expert advice, and constant experimentation.

How Long Should You Run Air Purifier
Turning on an air purifier. Photo: / Milan Antonic

Some air purifiers need a longer run, while others can filter the air in the room at rapid speed thanks to the high airflow. This is just one fact that makes running an air purifier a difficult question to answer. Each air purifier needs to be run at its best to give the best outcome.

This article will touch on the optimum time to use an air purifier during the day. I will also describe how energy-efficient it is to use an air purifier continuously throughout the day and whether switching off the device periodically improves energy efficiency and reduces costs. I will also touch on filter life, particularly during daily air purifier use.

How Long Does It Take to Run the Air Purifier for Fresh Air?

First, it is essential to understand that air purifiers are needed when the air in your room is terrible. They are also important when the air is good because then you want to maintain that good air quality. This further means that running an air purifier depends on many different factors. 

People who live in locations where forest fires are widespread choose to buy an air purifier. In such situations, it is crazy to turn off the air purifier as long as the fire is going on and as long as the air is polluted above average. You just simply need to keep it on and filter all that smoke.

How much electricity does an air purifier use
A tool I use when measuring air purifiers power usage. Photo: / Milan Antonic

However, using air purifiers during a sunny, fresh, day, it is also crazy to run the air purifier if the air is noticeably clean. It is therefore challenging to make optimum use of an air purifier. Fortunately, smart air purifiers with built-in smart sensors are increasingly appearing on the market, which gives you a whole new dimension in air purifier management.

In addition, many users, such as my brother, have problems with allergies, especially pollen. For example, he doesn’t even switch off the air purifier when pollen season starts. He uses it 24/7 because he feels that the pollen bothers him as soon as he switches it off.

I would like to say that the first thing to bear in mind is that whether you use the air purifier 8 hours a day, 12 hours a day, or 24 hours a day depends entirely on your situation and the quality of the air in your environment.

Some of the users I have spoken to prefer to use the air purifier when cooking or preparing food because of a nasty odor that is removed rapidly with an air purifier.

In any case, it would be ideal to have an air purifier running 24/7 so that you can be sure that you are breathing clean, pollutant-free air at almost all times.

How Long Until You Feel a Difference in the Air

If you are using an air purifier for the first time, believe me, after 30 minutes up to 1 hour, you will be surprised and delighted by how much better the air quality in your room seems to be.

Is it ok to run an air purifier on turbo mode all the time
Controls of an air purifier. Photo: / Milan Antonic

The time it takes for the air purifier to clean the air in your room depends on whether you have placed it in a room of suitable dimensions. The room coverage covered by the air purifier is defined as sq. ft. If the air purifier is designed for a room of 200 sq. ft., the device will clean the air in that room 5 times in one hour (this is according to AHAM standards).

For the device to completely clean the air in a 200 sq. ft. room, if it is designed for a room of this size, it will take approximately 1-2 hours. These are, of course, ideal conditions, which are not always the case and depend on many other factors:

Filter wear: air purifiers mostly use replaceable HEPA filters that you can quickly wash. However, they do have a shelf life. This means that over time the efficiency of your device will decrease, and the more you use it, the lower the filter quality will be. This will continue to happen until you replace the HEPA filter with a new one.

CADR: The time it takes for an air purifier to clean the air in a room depends on the speed at which it is running and the CADR (CFM) value it has. Note that if the air purifier has a CADR of 120, this value only applies to the maximum speed and has several times less CADR on a lower speed. Therefore, in addition to the size of the room in which it is used, the device’s efficiency also depends on the speed at which it is used. However, using the air purifier at maximum speed is not always an option, mainly due to the motor noise, which is usually unbearable at full speed.

Power consumption: it should be borne in mind that air purifiers need less power than some similar devices. Small air purifiers generally have an motor power of up to 50W, while slightly larger ones do not exceed 100W. However, suppose you use the device all day long. In that case, the power consumption can be a significant expense. Even when you factor in the price of replacement filters, you come to the conclusion that maintaining an air purifier is not cheap at all. There are many different air purifiers on the market; some have an ECO mode which, in combination with an air quality sensor, switches the unit on and off as needed (depending on the current air quality), something similar is done by Auto Mode, which optimizes the speed and therefore the energy consumption according to the current air quality. In short, there is always room for savings, and each air purifier tackles energy efficiency differently.

Location of the air purifier: indeed, one of the most important factors is the location where you will place the air purifier. It is not the same if you put the air purifier in a corner and leave it running 24 hours a day in that location, or if you put it in the middle of a room, for example, and leave it running at the same time. Obviously, the one in the middle of the room will be much better. I have written about this topic before, so I would definitely suggest you read the blog post on the best location to install an air purifier.

Maybe that’s too much information to capture, it’s perhaps easiest to just turn on the air purifier and leave it running, but if you want the best performance, optimum consumption, and consistently clean air in your room, then I definitely recommend following these suggestions.

Is It Safe to Leave the Air Purifier on All Day?

As I have already hinted in previous titles, using an air purifier 24/7 is absolutely possible and, in some cases, recommended. I have even noticed that many manufacturers recommend using an air purifier 24/7.

If you have already bought an air purifier, I assume that you feel that the air in the room you live in is polluted. Therefore, it is justified and expected that you use your air purifier for as long as possible to clean the air in your room as efficiently and thoroughly as possible and, among other things, keep the air quality at a high level for as long as possible.

If you are planning a trip or any other reason why you will be away from home for a while, leaving the air purifier on is not what I recommend. Not only do I not recommend leaving the air purifier on, but any other electrical appliance should be turned off. There have been cases where users have had problems with fire hazards due to a short circuit in the device, and now imagine that happening when you are on the road, and you cannot react in any way. Therefore, it is always better to prevent such situations, and I strongly advise you to switch off the air purifier when you know that you will be away from home for a long time.

In my opinion, if you are traveling, a much better option is to use a smart air purifier that you can switch on at any time from a remote location and turn on a few hours before you get home and enjoy the fresh air.


Should I turn off the air purifier at night?

Not necessarily. An air purifier can efficiently operate at night. Many models have a sleep mode specifically adapted to work at night.

Can you run the air purifier 24 hours a day?

Yes, definitely. This way, you can maintain the high air quality in your home at all times.

Do air purifiers get hot?

No. These devices use small, well-optimized motors that do not heat up easily, and in this way, they rarely overheat or get damaged.

Do air purifiers consume a lot of electricity?

These small devices use low-power motors and do not consume much electricity.

Final Thoughts

I hope that I have given you at least a little insight into the problem and that I have resolved any doubts you may have had about the air purifier working all day. Basically, it is all a matter of choice and how polluted is the air in the room you are in.

In short, if you feel comfortable using the air purifier 24/7, you can do so without any problems. Many manufacturers advise you not to turn the air purifier off. You can expect faster filter consumption and higher electricity consumption in this case. But perhaps the most important thing to pay attention to is to switch off the air purifier if you plan to be away for a long time.

If you have any questions, please post them in the comments box below.

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