The Ultimate Guide to Buying an Air Purifier

As an expert in the field of air purifiers, I have seen many mistakes made by consumers when it comes to purchasing these products. In this article, I will share with you the dos and don'ts of buying an air purifier, so you can make an informed decision and improve the air quality in your home.

Avoid False Promises

One of the biggest mistakes people make when buying an air purifier is falling for manufacturers that promise the most powerful engine. While a strong engine may seem like a good thing, it doesn't necessarily mean that the air purifier is effective at cleaning the air. Instead, look for a reputable brand with good reviews and ratings from trusted sources.

Don't Rely on Just a Medical-Grade HEPA Filter

Another mistake to avoid is purchasing an air purifier that only has a medical-grade HEPA filter.

While these filters are effective at removing fine particles from the air, they are not enough on their own. As Misha Kollontai, who oversees air purifier testing at Consumer Reports, explains, an air purifier should be seen as an add-on unit for a room, similar to a space heater in the context of a whole-house heating system.

Look for High CADR Ratings

The Clean Air Delivery Rate (CADR) is an important factor to consider when buying an air purifier. This rating reflects the volume of clean air produced by the purifier at its highest speed setting. For allergy sufferers and asthmatics, it is recommended to choose an air purifier that can clean the air in a space at least four times an hour.

Understand How Air Purifiers Work

It's important to have a basic understanding of how air purifiers work in order to make an informed decision.

As air enters the purifier, it passes through layers of filters that remove fine particles, and then clean air is released on the other side. However, it's important to note that air purifiers cannot eliminate larger allergens, dust mites, and pet hair unless they are disturbed and redistributed in the air.

Consider Noise Levels

Some people are bothered by the noise of an air purifier, especially if it is placed next to their bed. However, for others, the white noise produced by the purifier can actually help them sleep better. If you are sensitive to noise, look for an air purifier with a low decibel rating.

Do Your Research on Different Technologies

When researching air purification systems, you may come across a lot of buzzwords that seem promising.

However, it's important to understand the actual ability of these technologies to clean the air. For example, there has been little field research on the efficacy of PCO air purifiers, and a laboratory study conducted by researchers at Syracuse University found that these devices did not effectively remove VOCs from indoor air.

Choose the Right Size for Your Room

Air purifiers are optimized for cleaning rooms of specific sizes. Their power is measured by the frequency with which they can exchange all the air in the room, known as hourly air changes (ACH). When purchasing an air purifier, make sure to choose one that is suitable for the size of your room.

Invest in Multiple Units for Larger Spaces

If you have a larger space that you want to purify, keep in mind that portable air purifiers are designed to clean the air in a single room.

This means that you may need to invest in multiple units for different rooms in your home.

Don't Forget to Change Your Air Filter

Even with the best air purifier, it's important to regularly change your air filter. This is especially important for those with allergies or asthma, as pollen and other allergens can easily enter your home through open windows. Make sure to run your air conditioner or forced-air cooling system with a clean air filter to keep the air in your home clean and fresh.


In conclusion, when buying an air purifier, it's important to avoid certain mistakes in order to get the best product for your needs. Remember to choose a reputable brand, look for high CADR ratings, understand how air purifiers work, and do your research on different technologies.

By following these dos and don'ts, you can improve the air quality in your home and breathe easier.