Air Purifier Expert Buyer's

Air purifiers are handily portable devices that combine the power of an internal filter (though, there are air purifier models without filters as well) with a fan to remove unwanted particles from the air in a designated room. The freshly purified air is then circulated back into the room. An air purifier can eliminate pollutants like wildfire smoke, pet dander, dust, pollen, and other toxins in the air of a specific room. Air purifiers are the opposite of an oil diffuser or humidifier, in that they remove particles from the indoor air instead of adding particles to the air. In fact, the Environmental Protection Agency reports that particular pollutants can be anywhere from 2-5 times more concentrated indoors than outdoors. So, an air purifier is clearly a worthwhile investment.

In this guide, we review the different filter types built into air purifiers, as well as air purifiers that operate without filters and cutting-edge technology to sanitize the air. We also cover the particle removal process carried out by air purifiers, the different target pollutants of an air purifier, and the coverage, dimensions, and features of air purifiers.

How it Works

Filter Type

There are a wide array of air filters available for purchase. We’ll cover HEPA, True HEPA, charcoal, and filter-free alternatives, and what particular particulates each kind of filter is specifically designed to eliminate from the air. From there, you’ll be able to invest confidently in exactly what kind of air purifier you need to best address your air purification needs.

• HEPA Filter: The HEPA filter is commonly known as the most reliable filter. The HEPA filter is paired with an activated carbon filter, and it's extremely effective at catching a wide array of particulates that can be found within your home. The particulates that HEPA targets include dust, pollen, mold, bacteria, and any other airborne particles with a size of 0.3 microns. The difference between a True HEPA filtration device or filter and a normal HEPA filter is that the True HEPA filter specifically conforms to the DOE standard for HEPA filtration, is the most efficient, and is able to hit the required 99.97% threshold (the threshold for particulates captured).

• Charcoal Filter: Charcoal (or carbon) filters specifically remove odors, fumes, smoke, and other chemicals. Examples of these can include the gases in cigarette smoke or those that are given off by drying paint or cleaning products. Benzene, toluene, xylene, and some chlorinated compounds are additional examples of chemicals that can be removed by a carbon filter.
• Filter-Free Alternatives: A filter-free air purifier is able to deploy a stream of ions that are negatively charged in order to eliminate pollutants and contaminants in the air such as allergens, that most often consist of positively charged ions. There are also air sanitizers that are able to sterilize the air by using heat or UV light in order to eliminate viruses, bacteria, and spores. #### Particle Removal A HEPA filter, which is most commonly used by air purifiers, can theoretically capture and eliminate at least 99.97% of dust, pollen, mold, bacteria, and any other airborne particles that have a size of .3 microns. You should note that the specification of .3 microns represents the worst case. Particles that are bigger are trapped by the filter with even greater efficiency. Charcoal or activated carbon filters are able to remove pollutants from the air through a process known as adsorption. It’s key to note that this is completely different from “absorption” when a substance that you want to remove is actually absorbed into the structure of the absorbent. An example of this would be a sponge and water, and how the water itself doesn’t become chemically bonded to the sponge. Charcoal (or activated carbon) filters absorb the pollutants in the structure of the filter itself. The activation process for an activated carbon filter is crucial because the surface area gives gases a greater area to stick to. Over time you will need to replace the charcoal (activated carbon) filter because gaseous pollutants will eventually entirely fill up the adsorption sites of the actual carbon.

Lastly, filter-free air purifiers like air ionizers are able to use two plates that are each electrically charged, and then work together to thoroughly sanitize the air. One plate will charge the molecules flowing in and exiting the purifier. The electrical field that's in the actual air purifier charges all the molecules and lastly releases the newly sanitized air back into the enclosed area. The other most commonly used filter-free air purifier is an ultraviolet purifier. An ultraviolet purifier can kill viruses, germs, bacteria, and mold spores. Ultraviolet air purifiers are extremely effective and cost-efficient, using little electricity when operating.

Targets

Air purifiers that have HEPA filters can effectively capture numerous harmful particles that you can find indoors like pollen, pet dander, dust, viruses, and wildfire smoke. For starters, COVID particles are generally estimated to range between 0.06 to 0.14 microns, which is a size that HEPA filters have been shown to be effective in capturing. However, the EPA states that an air purifier with a HEPA filter doesn’t guarantee that you can’t still get sick after exposure to a virus. But, the air purifier will be highly effective in helping you and any other people in your household stay healthy.

Next, wildfire smoke is measured to range between 0.1 to 0.7 microns. When wildfire smoke is inhaled it can result in numerous health problems. These health problems include a burning sensation in the eyes, bronchitis, asthma attacks, and more dangerous conditions like a heart attack and stroke. The EPA additionally reports that wildfire smoke which is often made up of vegetation, natural fuels, and synthetic materials, has been attributed to causing premature death and difficulty in breathing for children. The great news is that HEPA filters are very effective at removing smoke. The EPA recommends air purifiers as being an effective tool to eliminate smoke.

Air purifiers are also extremely effective in capturing the microscopic flakes of skin and/or dander that your pets can shed around your home. Pet dander can range from 0.5 to 100 microns, and while consistent sweeping and vacuuming can be helpful in negating the unwanted effects of exposure to pet dander like intense eye-watering, an itchy throat, and even respiratory problems, an air purifier is much more thorough in its cleaning process. Next, air purifiers that are equipped with HEPA filters can effectively capture dust particles. When left unaddressed, dust can lead to serious health conditions if it’s inhaled deep within your lungs. Not only will an air purifier with a HEPA filter capture dust particles, but it can also capture dust mites, which are far too small for your eyes to pick up otherwise. Lastly, an air purifier with a HEPA filter is highly effective at capturing pollen. Pollen measures out to between 10-100 microns. If you’re someone who suffers from pollen-related allergies, an air purifier can thus significantly enhance your daily life.

Home Placement

It’s best to set up your air purifier so that it’s as close as possible to the source of the odors and/or potential allergens. Some example spots where your air purifier will perform at its best include: close to your dog/cat’s bed, in the kitchen close to the stove, and in any rooms that contain a lot of fabric or other materials that often gather a lot of dust.

Additionally, make sure to give your air purifier at least 6 inches of space away from any walls, doors, or furniture. You want to maximize the amount of airflow that the air purifier can generate with its intake fan. You also need to keep your air purifier away from other potential sources of heat to ensure that your air purifier doesn’t overheat from all the work that it gets done. Lastly, work to put your air purifier in a dry space that isn’t susceptible to excessive moisture exposure.

Specifications

Coverage

You’ll want to make sure that you invest in an air purifier that is sized relative to the size of the room that you plan on setting it up in. Simply use a measuring tape to measure the length and width of your room in feet. Then, multiply those two numbers to get the square footage of the room where you’re going to put your new air purifier. You can then calculate the volume of air in your room by taking the square footage of your room (in ft) and multiplying it by the ceiling height of the room (in ft).

As an example, consider the following: You have a 600 sq ft room with an 8 ft ceiling height. The total air volume of the room is 600 sq ft x 8 ft = 4,800 cubic feet. If you want an air purifier that will change all the air in the 600 sq ft room 2 times per hour, the air purifier will have to provide 9,600 cubic feet of cleaned air.

Your target range in terms of how many air changes per hour (ACH) your air purifier provides should fall within the 2-5 air change range. Anything within this range ensures that your air purifier is cleaning the air every 12-30 minutes. Additionally, if you live in a home with pets and/or smokers, you should aim for a maximum of 5 changes per hour. This will vastly cut down on the total number of allergens in your home.

In the event that you're actively interested in strategically eliminating different kinds of pollutants while also eliminating a troublesome odor in your home, you'll be best served by investing in at least 2 new air purifiers. This is because, you may need a charcoal air purifier to deal with an odor coming from your kitchen, while you'll also need a HEPA filter to thoroughly eliminate other pollutants like dust and pollen from a heavily frequented living space in your home like the dining room.

Dimensions

The dimensions of a specific air purifier will be measured in Width", Depth", and Height". You will need to take measurements in the particular living space where you plan to place your air purifier to ensure that it will fit properly. There are small, medium, large, and whole-house air purifiers. Small air purifiers are generally best for personal spaces and any rooms up to 200 sq ft. Next, medium air purifiers are effective in rooms between 200-400 sq ft. Then, large air purifiers are great for rooms ranging between 400-1,500 sq ft. Last, whole-house air purifiers are best for sanitizing the air in every room of your house.

Features

Modern air purifiers feature cutting-edge special features like an AUTO mode that includes a smart air quality sensor. This sensor can rapidly detect pollutants present in your air, and make real-time fan adjustments to optimize the air sanitation process. Plus, you’ll often have access to a digital display on the air purifier that shows your air quality level. Additionally, air purifiers with HEPA filters can include reset indicators that will flash and alert you when it’s time to replace the filter. There are also air purifiers with built-in warm night lights that feature easily customizable brightness levels, and a timer for the added convenience of an auto-shut-off capability. Air purifiers possess numerous high-tech functionalities that can greatly enhance their operational efficiency. Below are two of the main features worth considering when you're shopping for a new air purifier.

• Ultra-Quiet: Many air purifiers will run as low as 25db (most homes never exceed this during the day), and the special display light can auto-shutoff to help ensure you get an undisturbed night's sleep.
• Smart View Air Quality Sensor: Some air purifiers contain a built-in sensor that will scan the surrounding air for any pollutants, and then continuously update the display so that you can actively monitor the state of your air quality. By investing a bit more money in an air purifier that has additional special features like those that we've discussed, you’ll only stand to benefit that much more down the road from a low-maintenance and highly effective device.

FAQS

How much does it cost to run an air purifier?

Air purifiers are highly efficient in their electricity usage. They are designed such that their max wattage ranges anywhere from 40W to 200W, and that would be for the highest speed setting. As a helpful comparison, a fridge will use 3-5 times more energy on average. Most air purifiers that are available for purchase will only cost you max $7 a week due to their impressive energy efficiency.

How often do you need to change the filter in your air purifier?

You should make sure to replace your HEPA filter at least once a year, and sometimes more if it’s been exposed to a highly concentrated amount of particulates in the air. If you have an activated carbon filter, that will need to be replaced every 3-6 months. As previously mentioned, some air purifiers are filter-free and won't require you to invest in new filters. However, As mentioned some air purifiers like ultraviolet air purifiers and air ionizers don't use a filter to purify and may be worth considering if you don't want to bother with replacing filters down the road.

How frequently should you run your air purifier?

While the amount of time that an air purifier will take to improve the air quality of a given room varies, in general, you should run your air purifier at least a few hours per day. You’ll want to make sure to run your air purifier at least once per day to ensure that you benefit most from it. You could also run your air purifier 24/7 but should note that this will use more power, and you may need to replace and/or clean the air purifier’s filters more often.