What to Look for in an Air Purifier: 5 Essential Features

If you are going to spend money on an air purifier, it makes sense that you would take the time to compare different models and brands before making a decision. You want to get the most air quality improvement for your dollar, and you are not alone. That is why we put together this checklist of the top features — to demystify the buying process so you can choose the best air purifier for your home.

What makes a good air purifier?

When it comes to buying an air purifier, the goal is simple: to improve the air quality of your home or office. However, wading through lists of technical specifications can make your choice seem far from easy. To make the process more straightforward, identify the main reason that you want an air purifier. What is your top air quality concern — allergies, asthma triggers, wildfire smoke or something else? The best air purifier will address your specific air quality issues while blending seamlessly into your space. Before you start shopping around, we suggest sitting down and determining the most important things that you want from your air purifier. Then, you can let those priorities help guide your search.

What are the top air purifier features to consider?

Thanks to vast technological advancements in recent years (and the ease of online shopping), there are more household appliances on the market than ever before, each boasting newer and better features than the last. How do you cut through the noise and decide what really matters in an air purifier? The answer depends on your preferences and objectives for these five factors:

1. Type of filtration technology

Choosing the right filtration technology is probably the most important part of buying an air purifier. Remember when you listed your specific air quality concerns? This is where they come into play. Different types of filters can tackle different types of indoor air pollution. It is crucial to make sure that you are getting one that can handle your specific needs.

  • HEPA filters are designed to capture airborne particulate matter, such as dust, pollen and pet dander. True HEPA filters capture at least 99.97% of particles 0.3 micrometers (µm). However, these filters are ineffective against any gaseous pollutants. Units with HEPA filters may mention industry standards such as CADR or MERV values, but these numbers are not necessarily the best indicators of an air purifier’s performance.
  • Carbon filters trap gaseous pollutants, such as VOCs, in the air through a process called adsorption. As these filters become more saturated, they become less effective. Activated carbon filters cannot remove particle pollution from the air.
  • PECO-Filter technology goes beyond simply trapping airborne pollutants. Instead, this patented Molekule technology destroys pollutants like VOCs at the molecular level.
  • Ionizers work by releasing charged ions into the air. These ions then attach to airborne particles, giving them a charge that makes them either attach to surfaces in your home (such as walls and furniture) or fall to the ground. The technology used in some ionizers can create ozone as a byproduct, which may cause a long list of harmful health effects according to the California Air Resources Board (CARB).

2. Design and ease of use

A lot of things fall under this umbrella, such as aesthetics, portability, ease of set-up and Wi-Fi accessibility. Consider the room in which you will place your air purifier. You want to choose a model integrates into your daily life with minimal interruption. For you, that may mean matching your home decor. For others, it may mean having something that they can set up and forget about. Some questions to consider include:

  • What are the dimensions and weight of the air purifier unit?
  • What is the size of the room in which you will place your air purifier?
  • How complicated is the user interface?
  • How many settings options does the unit have?
  • Can the air purifier be controlled by a phone app or remote?
  • Will the air purifier notify you when it is time to replace the filters?

3. Noise level

If an air purifier is too loud, the chances of you using it regularly are slim to none. Whether you like to relax in total silence or enjoy having white noise playing in the background, checking an air purifier’s sound ratings can help give you a better idea of what to expect in terms of noise. (Keep in mind, an air purifier’s noise level will change with different fan settings.) The quietest air purifiers on the market will have a dB rating of 20-40 at the lowest fan speed, while the loudest ones will be rated 50 to 70 dB and above. To put this into perspective:

  • 30 dB is about the same noise level as a whispered conversation.
  • 50 dB is similar to a normal conversation or moderate rainfall.
  • 70 dB is as loud as running a vacuum or sitting in rush-hour traffic.

4. Energy consumption

If you are not careful, your air purifier’s energy consumption can lead to unpleasant surprises on your monthly electricity bill. To keep energy costs low, try looking for units that use below 100 watts on their highest setting. For example, our Molekule Air uses 20 to 80 watts of energy when in use, and the Molekule Air Mini only uses 18 to 53 watts. The Office of Energy Efficiency & Renewable Energy provides an online calculator that can help you determine how the addition of an air purifier can impact your yearly energy bill.

5. Cost of maintenance

During the life of your air purifier, you will need to replace the filter(s) regularly. Filter life can range from a few months to a year, depending on the pollutant levels in your home and the type of filtration technology in the unit. When considering the cost of an air purifier, make sure to factor in the average yearly cost of filter replacements (the cost of replacement filters multiplied by the number of times the filters need to be changed each year). Note that some air purifiers have more than one filter that will need to be replaced regularly.

Additionally, note the air purifier’s warranty and return policy. What happens if the air purifier breaks or you realize that it is not right for your home? When you are investing in an air purifier, you want to know that you will be in good hands if anything breaks, or if you decide to return the product.

Which air purifier features should you avoid?

When we are talking about air purifier features such as Wi-Fi accessibility and filter status indicators, it may seem like more is better, but that is not always the case. The top three air purifier features to avoid are:

1. Ozone emissions and ionizing functions

If there is any chance that an air purifier will emit ozone, either on purpose or as a byproduct of its operation, you probably do not want to bring it into your home. Ozone is a toxic pollutant known to cause harm to the cells in the lungs and airways. An easy way to check for this is to see whether the unit has been certified by the CARB.

2. Primary UV-C (germicidal) light technology

Like ionizers, air purifiers that primarily use ultraviolet UV-C light may also emit ozone, according to CARB. If the air purifier uses UV-C tech or has a UV-light feature, you can double check if it is certified by CARB here. Plus, considering the low levels of UV light present in residential air purifiers, it is doubtful that this feature provides a significant added air quality benefit. Some manufacturers add optional features such as this to justify inflating the price of their devices. Note that the Molekule air purifier uses UV-A light, and not harmful UV-C light, solely as a method to initiate a catalytic reaction that occurs on the surface of the filter.

3. Fanless air purification

Fanless air purifiers may seem like a great option for those who are looking for a quieter option, but they have a serious downside. Without a fan, an air purifier cannot get enough airflow to replace the air in the room completely. These types of air purifiers can only remove a small fraction of the pollutants removed by an air purifier with a fan.

We understand how easy it is to feel overwhelmed by the vast selection of air purifiers on the market today. Fortunately, once you know which type of air filter best handles your top air quality concerns, your search for an air purifier becomes much more manageable. Then, it is only a matter of finding a model that is right for your room size, design preferences, noise level and budget.