Clean air is essential for everyone, but especially for people with COPD. Allergens like pollen and pollutants in the air can irritate your lungs and lead to more symptom flares.

The air in your home or office might seem clean enough. But what you can’t see could hurt you.

Tiny particles of pollutants like smoke, radon, and other chemicals can get into your home through open doors and windows as well as your ventilation system.

There are also indoor pollutants that come from cleaning products, the materials used to build your home, allergens like dust mites and mold, and home appliances.

The combination of these sources is why the concentration of indoor pollutants is two to five times higher than those of outdoor pollutants, according to the Environmental Protection Agency.

One way to clear the air in your home is by using an air purifier. This stand-alone device sanitizes the air and removes fine particles like pollutants and allergens.

Purifiers filter the air in one room. They’re different from the air filter that’s built into your HVAC system, which filters your whole house. Air purifiers can cost hundreds of dollars.

An air purifier can help clear your home’s air of allergens and pollutants. Whether it will help improve COPD symptoms is still uncertain. There hasn’t been much research. The results of the studies that do exist have been inconsistent.

Yet the research does suggest that reducing particles and allergens in the air may ease lung symptoms.

For example, some studies have shown that air cleaners that capture large amounts of allergens and dust particles improve lung function in people with asthma.

There are several types of air purifiers. Some work better than others. A few might actually be harmful to your health. Here’s a quick breakdown:

  • HEPA filters. This is the gold-standard filter for removing airborne particles. It uses mechanical ventilation — fans that push air through pleated fibers like foam or fiberglass — to trap particles from the air.
  • Activated carbon. This model uses an active carbon filter to trap odors and gases from the air. Although it can catch larger particles, it typically misses smaller ones. Some purifiers combine a HEPA filter with an activated carbon filter to trap both odors and pollutants.
  • Ultraviolet (UV) light. UV light has the ability to kill germs like viruses, bacteria, and fungi in the air. For a UV air purifier to kill these germs, the light must be strong and stay on for at least several minutes or hours at a time. This isn’t the case with all models.
  • Ionizers. Normally, particles in the air have a neutral charge. Ionizers negatively charge these particles, which makes them stick to plates in the machine or other surfaces so you can clean them away.
  • Electrostatic air purifiers and ozone generators. These purifiers use ozone to change the charge of particles in the air so they stick to surfaces. Ozone can irritate the lungs, making it a bad choice for people with COPD.

The key to a good air purifier is that it filters out particles 10 micrometers or smaller in diameter (a human hair is about 90 micrometers wide).

Your nose and upper airway are pretty good at filtering out particles larger than 10 micrometers, but particles smaller than that can easily get into your lungs and bloodstream.

Air purifiers that contain a HEPA filter are the gold standard. Choose one that contains a true HEPA filter, rather than a HEPA-type filter. Although it’s more expensive, it will remove more particles from the air.

Avoid any purifier that uses ozone or ions. These products could be harmful to your lungs.

Using an air purifier may help clean the air in your home so you breathe in fewer particles that could irritate your lungs.

Cleaner indoor air might help your heart, too.

Exposure to particles in the air can contribute to the inflammation that damages blood vessels. In studies, filtering the air led to improved blood vessel function, which could contribute to better heart health.

When choosing an air filter, you have a few different options.

HEPA stands for high-efficiency particulate air. These filters are highly effective at clearing the air because they remove 99.97 percent of particles 0.3 microns (1/83,000 of an inch) in diameter or larger.

For every 10,000 particles of that size that enter the filter, only three will pass through.

When choosing a HEPA filter, look at its minimum efficiency reporting values (MERV). This number, which goes from 1 to 16, shows how effective the filter is at trapping certain types of particles. The higher the number, the better.

Some air filters are disposable. You change them every 1 to 3 months and throw out the old one. Others are washable. You check them once a month, and if they’re dirty, you wash them.

Disposable air filters offer more convenience, but you’ll spend more to keep replacing them. Washable air filters save you money, but you’ll need to keep up with the cleaning.

In addition, filters are made from several different materials:

  • Pleated filters are designed to last longer with less maintenance.
  • Polyester filters trap lint, dust, and dirt.
  • Activated carbon filters help control odors in your home.
  • Fiberglass filters are made from spun glass that traps dirt.

You need to keep the filter in your air purifier clean so it can work effectively. Plan to clean your purifier about once a month.

The only filters you should never wash are HEPA or carbon filters. Change these filters every 6 months to 1 year.

To clean your filter:

  1. Turn off and unplug the air purifier.
  2. Clean the outside with a damp cloth. Use a soft brush to clear any dust out of the top air vent.
  3. Remove the front grill and prefilter and wash them with warm, soapy water. Dry them with a towel before putting them back inside the machine.
  4. Use a dry, soft cloth to wipe down the inside of the air purifier.

An air purifier can remove some pollutants and allergens from the air in your home. While these machines haven’t been proven to help with COPD, they may improve asthma symptoms.

For best results, choose a purifier with a HEPA filter. Make sure to keep your air purifier clean by regularly washing or changing the filter.