Should I Turn Off My Air Purifier At Night Or Leave It On?

So you brought the latest and most powerful air purifier on the market. Everything looks great and the air is being filtered as we speak. Your allergy symptoms have gone and overall indoor air quality has improved. Yet, there is the question that always has been lingering in your head. Am I suppose to leave the air purifier on all the time or let it cool down to avoid overheating? What about the electricity cost?
Short answer
Leave it on all day, every day.


Can You Leave Air Purifier On All The Time?

You should leave your air purifier on continuously so there is a constant flow of purified, clean air. When the air purifier is turned off, it will stop filtering the air and harmful particles like dust, pet dander, mold, pollen, bacteria, viruses will gradually return within 2 to 4 hours. The only time you should not be running an air purifier is when there is a safety hazard such as a damaged power cord, dirty filters, or the presence of an ozone generator that diffuses harmful ozone.

Should I Sleep With Air Purifier On?

As we spend about one-third of our life sleeping, keeping an air purifier on at night can improve your sleep quality and overall health. With an air purifier continuously removing airborne contaminants while you sleep, you will be at less risk of breathing into the allergens and wake up feeling refresh the next day. Without an air purifier, airborne allergens will build up overnight and can disrupt your sleep by triggering allergic reactions e.g. night cough, choking, sinus. You can learn more about the best bedroom air purifiers that we reviewed recently here.

Should I Leave My Air Purifier On When I’m Not Home?

Yes, you should leave your air purifier running when you’re not at home to ensure airborne particulates are always removed. You will be greeted with clean, fresh air when you return from work or holiday rather than having to wait for the air purifier to restart the cleaning cycle. As air quality in your home will drop every time you turn off the device, it is not possible for the room to remain clean with only a couple of hours of runtime.

Is It Safe To Run An Air Purifier All The Time?

It is perfectly safe to leave an air purifier on all day, all night even if you’re not around or out of town. Air purifiers are designed to run 24×7 that will not overheat, break down, or release harmful byproducts as it is typically powered by a mechanical HEPA filtration. Most models are also CE/ UL listed with strict safety compliances and CARB certified to be ozone-free so there is nothing to worry about.

Is It Costly To Run An Air Purifier All Day?

It is not costly to run an air purifier compared with other home appliances. Some model has a power consumption rate equivalent to a light bulb. Even if you run it 24 hours a day, you will not see a huge spike in your electric bills.

We do not recommend running an air cleaner intermittently in order to save cost. It is far from economical and you will be at risk of inhaling harmful contaminants. The air cleaner will also have to work extra hard to restore back the clean air and may end up using more energy thus a higher utility bill. Instead, pick an Energy Star Rated air cleaner or model that comes with Auto mode that conserves energy by only using higher fan speed when there is a high concentration level of pollutants detected.

To calculate the running cost of an air purifier, multiply the energy consumption with the rate of electricity (by states) and hours of operation. For the monthly electricity bill, just multiple the cost by 30 days.

Should I Open Windows With An Air Purifier On?

Depend on the air quality outside, you should keep all windows shut to reduce the number of irritants from flowing in. Even if outdoor air is not polluted, leaving windows open forces the air cleaner to work harder as unfiltered air is coming in and clean air is going out.

Optimizing An Air Purifier That Runs All-day

Airborne pollutants do not take a break while you sleep or go away. If you plan to run an air purifier day and night, it is important to check on the filter condition. A dirty filter is less effective as more and more particulates are trapped inside. You will need to replace the filter when it reaches its lifespan typically between 6 to 12 months or when the filter change indicator is flashing. You can also reduce the air purifier workload by vacuuming regularly to keep your home clean and tidy. Every little bit of effort counts.



Max Fernandez

A loving father and a dedicated reviewer for airfuji.com with more than 1000 air purifiers under his belt. Max Fernandez is also one of the million patients currently suffering from asthma. Feel free to nudge him if you have any questions.