Best Air Purifiers in 2023

What is an air purifier?

An air purifier is an electronic device used to clean pollutants from the air and improve air quality. It is normally rectangular or square. It is speficially designed for people who suffer from allergies or asthma. Air purifiers can either be standalone units or attach to an HVAC or air handler unit (AHU). Air purifiers are used not only in residences but also in the commercial, industrial, and medical industries. 

The two main methods of purifying the air are active and passive; the most common and effective air purifiers are passive. Inside the passive air purifier is a suction tube to draw in air, which passes over a filter. There’s also a fan to blow the clean air back out. The larger an air purifier is, the more powerful fan motor and airflow capacity it can accommodate.

Pollutants can include any of the following in combination:

• Dust: Dust is a mixture of human hair, sloughed-off skin cells, clothing fibers, dirt, pollen, dust mites, bacteria, bits of plastic, or anything that is dry and can flake off. When there’s not enough surface cleaning and clear air circulation, dust settles.
• Pollen: Pollen consists of plant spores or grains that are male sperm cells (gametes), which cause hay fever and other allergies in many people.
• Smoke: The smoke that people seek to remove from their homes is usually tobacco smoke, but it can also include smoke from the kitchen.
• Pet dander: Sloughed-off skin cells, pet fur, and saliva make up pet dander. However, people who are allergic are specifically reacting to a protein in the pet’s saliva.
• VOCs: Volatile organic compounds are gas emissions from solids or liquids that have a variety of chemical compounds.
• Mold spores: Excess humidity can be a problem in homes, especially in certain rooms. Mold and mildew thrive in environments that are moist and damp and have poor circulation.
• Pathogens: Viruses and bacteria are the smallest particles, and they need medical-grade filters as well as sanitizing.

Air purifiers are designed to remove particles that are a certain micron size or larger, depending on the type of filter that is used. Some, especially the newer models, have pre-filters and fabric or activated carbon filters to trap hair and other large particles. Newer models also tend to have features such as several fan speeds, a timer, filter replacement indicators, and pollution sensors. It is recommended to use only the replacement filters for your specific make and model of air purifier.

Types of air purifiers

There are many types of air purifiers on the market today, each with its own pros and cons:

• HEPA: HEPA stands for High-Efficiency Particulate Air filter, and a HEPA filter is an extremely dense, pleated mechanical air filter for trapping airborne pollutants. A “True HEPA Filter” removes 99.97% of particles as small as 0.3 microns in size, including dust, pollen, pet dander, smoke, and mold spores. Usually made of fiberglass and sometimes nonwoven fabric material, those that feature the ability to remove particles measuring 0.1 microns or larger have a diffusion component as the last trap for particles that don’t stick to the fibers. The disadvantages of HEPA are upkeep and the fact that it doesn’t remove pathogens or odors.

• ULPA: ULPA stands for Ultra-Low Penetration Air filter. It removes 99.99% of particles that are 0.1 microns or larger. Since it offers more filtration than is often needed in a home, it is typically used for biosafety cabinets and sterile rooms.
• Activated carbon: Also called absorbent, this type of filter has activated carbon material that is highly absorbent, enough to trap gases, volatile organic compounds (VOCs), and other toxic chemicals, and even remove lingering odors from gases and small particle pollutants. It uses physical absorption, chemical absorption, or both, to remove pollutants with particle sizes ranging from 0.5 to 50 microns and to release purified air. The disadvantage of activated carbon is that it doesn’t remove airborne particles and so is not a stand-alone product. It often comes as a pre-filter for HEPA air purifiers.
• Negative ionization: Also called ionic, this type of air purifier is also called an air cleaner. This type of technology creates a small powerful electrical field that creates oppositely charged particles, or negative ions, that attract pollutants. It weighs particles down, making them settle and stick to surrounding surfaces or fall to the floor, so they are easier to clean. Ionization can remove particles as ultra-fine as 0.01 microns in size. Another type of ionizer is called electrostatic precipitation, and it works almost the same way. Instead of making the particles fall on outside surfaces, the particles are drawn in and fall onto positively charged plates, which can then be cleaned. While filter-less and quiet, ionic air purifiers don’t remove particles as well as HEPA purifiers. They also produce ozone, which can create particle pollution and higher levels of formaldehyde.
• Ultraviolet (UV) light: UV light air purifiers kill airborne mold, bacteria, and viruses at the DNA level. The UV-C light produced by the UV lamp is exposed to air passing through the air purifier and sterilizes the air while it is filtered. One caveat is that UV-light air purifiers do not remove pollutants, so this technology is often combined with a filter. HEPA air purifiers sometimes have a UV light pre-filter. The disadvantage is that it creates ozone as a byproduct.
• Ozone generation: Ozone air purifiers change oxygen (O2) molecules into ozone (O3). They are not approved for occupied spaces and are, instead, typically used in industrial settings to purify the air of biological contaminants.
• Electronic: A whole-home solution, the electronic air purifier needs professional installation. It uses a combination of HEPA and ionization to improve air quality.
• Central air cleaner: Another whole-home solution, a central air cleaner needs professional installation and works through your HVAC unit.
• Air-to-air exchanger: The air-to-air exchanger is another whole-home solution that requires professional installation. It accomplishes air purification and improves air quality by recycling air and providing ventilation. If it has energy recovery ventilators, it can also help manage humidity and temperature in the home.

By far the most common types of air purifiers are HEPA and activated carbon. There are many air purifiers using both HEPA and activated carbon, which are not only affordable but very efficient in removing 99.97% of pollutants as well as odors and VOCs. Other air purifiers use some combination of mechanical and electrostatic filtration as well as features such as UV light and a humidifier or dehumidifier. They are called hybrid filters.

Air purifier vs. HVAC air filter

The air filter that attaches to your HVAC unit is only able to trap larger dust and dirt particles from the air. It is designed to reduce damage to the unit and its function from the larger particles. There are air filters designed specifically to help people suffering from allergies or asthma, but experts recommend using a stand-alone or whole-home air purifier as well.

Air purifier with pre-filter

Some air purifiers on the market today have multiple filters, including a pre-filter. The pre-filter may or may not be washable. It is designed to capture larger particles that would get stuck in the HEPA filter and increase the latter’s lifespan. it increases noise, reduces airflow, and reduces effectiveness by 40%. Even air purifiers without pre-filters outperform those whose pre-filters are frequently changed. However, people who worry about fur from pets can benefit, and strong fans in air purifiers will keep the pre-filters from restricting airflow as much.

Air purifier with permanent or washable filter

Having to do a lot of upkeep by changing the filter in the air purifier every few months can cost a lot of money. That’s why air purifiers with permanent washable HEPA filters are becoming increasingly popular. The most common one is a HEPA filter, which is just as effective as its non-washable counterparts. A similar washable and reusable filter is called an iFD filter. The permanent filter cannot be cleaned with soap and water but, instead, must be cleaned with vacuum cleaner tools. The disadvantage to both the permanent and washable air filters is that they cannot remove particles that are 2 microns or smaller, including fungi, bacteria, viruses, and some allergens.

Air purifier with humidifier or dehumidifier

Air conditioning and ventilation can help to dehumidify the air, but sometimes, they’re not enough. Dry air can also be a problem, one with which air conditioning and ventilation cannot help at all. Instead of purchasing an air purifier and a humidifier or dehumidifier separately, it’s much more economical to get a hybrid purifier. Also called an air purifier combo with a humidifier (or dehumidifier), it not only improves air quality but adds or removes moisture. Excess moisture can cause breathing issues in people with asthma or COPD and promotes mold and dust mites, while excess dryness causes nosebleeds, dry skin and mucous membranes, allergic reactions, and breathing issues.

Air purifier with UV-C light

Air purifiers using just filters can remove most particles and pollutants. They can also remove airborne mold spores. However, they cannot remove or kill viruses and bacteria. Air purifiers with UV-C light can do both. The disadvantages are that they’re so intense that they can burn people, and many generate ozone. They are also only for small to medium-sized rooms.

Air purifiers for specific needs

Air purifiers tend to focus on targeting certain problems in air quality:

• Breathing issues: HEPA filter air purifiers remove dust, smoke, pollen, and other potential triggers of asthma, allergies, and other conditions such as COPD. They are the most common type of air purifiers on the market today.
• Pets: Standalone HEPA air purifiers are not as effective for removing pet dander and especially odors unless they are designed specifically for people with pets. They usually have both a HEPA filter and a carbon pre-filter.
• Smoke: While many air purifiers remove smoke particles effectively, they cannot remove odors. Those that also remove smoke odors typically have a pre-filter plus a HEPA filter, or a pre-filter, carbon filter, and HEPA filter.

Air purifiers for small spaces vs. large spaces

It is very important to choose the right size of air purifier for the room whose air quality you want to improve. Otherwise, the air purifier will not be able to work effectively. A portable air purifier is often all that is needed for a small room of a certain size. There are also air purifiers for medium-sized or medium-to-large rooms. However, it can be difficult to find air purifiers for large and extra-large rooms. A solution is to purchase multiple air purifiers that each cover a certain amount of square footage.

Air purifier certifications

Here are a few of the most important types of air purifier certifications:

• CARB: CARB certification is done by the California Air Resources Board to limit the ozone emissions from indoor air cleaners.
• Clean Air Delivery Rate (CADR): The Clean Air Delivery Rate is a measurement of the cubic feet per minute (CFM) of air that has had certain particles removed, such as pollen/dust/smoke. A good CADR rating is at least two-thirds of a room’s area in square feet.
• Energy Star: An Energy Star rating means the product has met federally mandated guidelines for energy efficiency. Energy Star products use less energy and save money over time more than non-Energy Star products, about 9% in comparison.

How much noise does an air purifier make?

The noise level of an air purifier is usually given in a decibel range. However, some are fairly well set at a certain level. Most people agree that 40dB is tolerable during the day but difficult to handle when trying to sleep at night. Others may find it difficult to hear the TV over any background noise, including that of an air purifier.

How much does an air purifier cost?

There are several factors that go into the cost of an air purifier. First, there is the initial cost. The second factor is the power consumption of the product, which adds to your energy bill. The last factor is the upkeep to maintain it, including changing or cleaning the pre-filter, carbon filter, and/or HEPA air filter. While it is possible to buy an inexpensive air purifier that is not durable or efficient, there are many air purifiers that work very well and are affordable. The more features an air purifier has, the more expensive it tends to be.

How do I choose the air purifier that’s best for me?

When deciding on an air purifier to buy, consider the following factors:

1. Room size
   
2. Budget
3. Targeted particles
4. Particle size
5. Power consumption
6. Noise level
7. Additional features