The first answer is always… wait for it… It Depends! Most people who purchase an air purifier for the home or office do so to reduce the effects of allergens or smoke. Having selected an efficient and powerful air purifier, you may notice a dramatic improvement in the air quality of your home. However, to achieve maximum results from your machine, it is important to know when to operate it and for how long. How Long Should You Let It Run for Maximum Effect? Air purifiers are designed and meant to be used for extended periods of time. It is a common misconception that operating an air purifier for an hour or two in a room will sufficiently clean the air. New particulates swirl around in the air all the time. Humans, pets, air-conditioning and heating systems, and open windows are all responsible for introducing contaminants into a room. How long to run your purifier greatly depends on its make, model, and type. Your user manual should give you a guideline, but generally you want to keep it on for between five and eight hours at a time, keeping in mind that you can always turn it back on after it has had a rest. Austin Air Purifiers, being the best in class, are commercial grade heavy-duty built and can be run 24/7, and yes they can be run all the time—warranty is for 24/7 operation!! 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 4-6 air changes every hour. With this assumption, you can safely run your air purifier at least 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. Should You Turn Off Your Air Filter to Save Electricity? Those who want to operate air purifiers in the home are often worried about conserving electricity. To run one or more older model allergen removers for many hours at a time not only wears out the filters and the machines themselves, but also expends an enormous amount of electricity. To conserve as much electricity as possible, consider operating it during times of the day when you will be inside the home. Similarly, if you are not using the purifier to reduce allergies, consider keeping windows open to allow for ventilation of smoke or other undesirable particles in the air, if the weather allows. You may want to consider putting it on a adjustable timer to suit your lifestyle and prevent you forgetting to turn it on in time or forget to turn it off as desired. As always, this is general advise, and your home and needs may be different. Feel free to call and discuss at 205-252-9506 if you wish.