Does an air purifier really help with allergies?

If you suffer from allergies, you know how debilitating it can be. Congestion, sneezing, and itchy eyes can derail your whole day. One potential solution that has gained popularity in recent years is the air purifier. But do these devices really help alleviate allergy symptoms? In this article, we'll explore the science behind air purifiers and find out if they can be effective in managing allergies. Let’s clear the air… literally. 

Do air purifiers help with allergies?

The short answer is yes, air purifiers can help with allergies. These devices work by removing airborne pollutants and allergens from the air, reducing the amount of irritants that can enter the body. By capturing particles like dust, pollen, and pet dander, air purifiers may help alleviate symptoms like congestion, sneezing, and itchy eyes.

Which allergens can they help with?

Air purifiers are effective against a range of common allergens, including:

• Dust: They can capture dust particles, including fine and larger particles, reducing the amount of dust that settles on surfaces and becomes airborne. This can be especially beneficial for people with respiratory allergies such as asthma.
• Pollen: By removing pollen from the air, air purifiers may help alleviate symptoms for people with seasonal allergies, such as hay fever. Pollen counts can be particularly high during peak seasons and air purifiers can help reduce exposure to these allergens. 
• Pet dander: Air purifiers can capture pet dander (flecks of dead skin shed by animals), reducing the amount of allergen that becomes airborne. This can be especially beneficial for people with pet allergies, as pet dander can become embedded in furniture and carpets making it difficult to eliminate.
• Mould: Some air purifiers can capture mould spores, reducing the risk of allergic reactions. Mould can grow in damp environments and air purifiers can help reduce exposure to mould spores.
• Other allergens: Air purifiers can also capture other airborne allergens such as: 
• Smoke: from wildfires or tobacco smoke 
• Insect particles: including things like cockroach allergens etc 
• Viral and bacterial particles: helping to reduce the transmission of airborne infections 

Air purifiers may also be beneficial for people with:

• Asthma: By removing airborne pollutants and allergens, air purifiers may help to alleviate asthma symptoms and reduce the risk of attacks.
• Eczema: While air purifiers won't cure eczema, they can help reduce the amount of airborne allergens that contribute to skin irritation.

How to use an air purifier to manage allergies

To maximise the effectiveness of your air purifier and maintain optimal air quality in your home, consistent and strategic usage is key. For continuous benefits, it's recommended to run your air purifier all year round, 24/7, especially if you suffer from allergies or live in an area with consistently poor air quality.

To get the most out of your device, consider the following detailed tips:

Strategic room placement

Where you put your air purifier makes a big difference to how effective it’s going to be. Place the air purifier in the room where you spend the most significant amount of time. For many, this will be the bedroom, as people typically spend 7-9 hours sleeping there. 

But if you work from home, your home office or a common living area might be a more suitable primary location during the day. If you have multiple air purifiers, distribute them in areas with high foot traffic or where allergens are most problematic. Make sure the purifier isn't blocked by furniture or curtains, allowing for optimal air circulation.

Continuous operation for optimal air quality

For consistent air purification, run your device all the time. Turning it on and off can lead to fluctuations in air quality, allowing allergens and pollutants to build up before the purifier has a chance to effectively remove them. 

Having your purifier on continuously allows the air in your chosen space to be constantly filtered, creating a healthier environment. Modern air purifiers are often energy-efficient, making 24/7 operation feasible without significantly impacting your electricity bill.

Regular maintenance for sustained performance

An air purifier's effectiveness hinges on proper and regular maintenance. Over time, filters become clogged with the particles they've captured, reducing airflow and its ability to clean the air. To keep things running smoothly, regularly clean and replace HEPA and carbon filters according to the manufacturer's recommendations.

Usually, HEPA filters need replacing every 6-12 months, and carbon filters every 3-6 months, depending on how much you use it and what your home’s like. If you neglect filter maintenance, it can lead to a less efficient unit, or even one that starts recirculating pollutants back into your air.  So, check your model’s manual for the exact schedule and keep that air fresh. 

How to choose the right air purifier

When selecting an air purifier, there’s a few factors to consider to ensure optimal performance and effectiveness. These include: 

Clean air delivery rate (CADR)

A fundamental metric, CADR indicates how quickly an air purifier can remove pollutants from a room. It's measured in cubic feet per minute (CFM) and provides a clear understanding of the purifier's efficiency. A higher CADR means the unit can clean a larger volume of air more rapidly. 

When evaluating CADR, it's essential to match the purifier's capacity to the size of the room where it’ll be used. An air purifier with a CADR too low for the room size will struggle to effectively clean the air, while one that's too powerful might be overkill and less energy-efficient.

Filter type

The heart of an air purifier lies in its filtration system. Among the various filter types, a High-Efficiency Particulate Air (HEPA) filter is seen as the gold standard for allergy sufferers as it’s designed to capture an impressive 99.97% of airborne particles as small as 0.3 microns. This includes common allergens such as pollen, pet dander, dust mites, mould spores, and even some bacteria and viruses. 

Beyond HEPA, some purifiers also incorporate activated carbon filters, which are excellent for removing odours, volatile organic compounds (VOCs), and gases, providing a more comprehensive air purification solution. Pre-filters are often used to capture larger particles, extending the lifespan of the HEPA and activated carbon filters.

Room size

Getting the right size air purifier for your room size is key  to making sure it actually works. Manufacturers usually provide clear recommendations for the maximum room size their purifiers can effectively cover, often indicating the number of air changes per hour (ACH) it can achieve within that space. 

Selecting a purifier that is appropriately sized for your room ensures that it can adequately circulate and clean the air. Using a purifier designed for a small bedroom in a large living room will likely be ineffective. Conversely, an oversized purifier for a small space might lead to unnecessary energy consumption and noise. For allergy relief, aiming for a purifier that can achieve at least four to five air changes per hour in your chosen room is generally recommended.

By carefully considering these three key factors (CADR, filter type, and room size) you can make an informed decision on which air purifier can help provide a healthier indoor environment, particularly for those prone to allergies. 

Other considerations might include noise levels, energy efficiency ratings, smart features (like app control or air quality sensors), and design aesthetics, all of which can enhance the overall user experience.

Other ways to manage allergies

While air purifiers can be a valuable tool in managing allergies, they're not the only solution. A comprehensive approach is often required to effectively manage allergy symptoms and improve overall wellbeing. Other crucial strategies to consider include:

Avoiding allergens

The most effective way to manage allergies is to identify and consistently avoid the specific allergens that trigger your symptoms. 

This might involve allergy testing to pinpoint exact triggers, followed by adjustments to your lifestyle and home environment. 

For instance, if dust mites are an issue, regular washing of bedding in hot water and using allergen-proof covers can help. If pet dander is a problem, limiting exposure to pets or creating pet-free zones in your home may be necessary. For pollen allergies, staying indoors during peak pollen times and keeping windows closed can significantly reduce exposure.

Using medication

Over the counter medications can play a vital role in alleviating allergy symptoms. 

These can range from antihistamines to relieve sneezing, itching, and runny nose, to nasal corticosteroids for reducing inflammation in the nasal passages. 

Decongestants can help clear stuffy noses, while eye drops can relieve itchy, watery eyes. 

Maintaining a clean environment

Regularly cleaning and dusting your home is essential to reduce allergen levels. 

Dusting with a damp cloth can help trap dust and allergens rather than scattering them into the air. Vacuuming frequently, especially with a vacuum cleaner equipped with a HEPA filter, can effectively remove allergens from carpets and upholstery. 

Washing curtains, rugs, and bedding regularly can also help minimize the accumulation of dust mites and other allergens. Controlling humidity levels in your home can also deter mould growth, another common allergen. Aim for indoor humidity levels between 30% and 50%.

The bottom line

Air purifiers can help reduce allergy symptoms by trapping a wide range of airborne pollutants. These devices work by drawing in air from the surrounding environment and passing it through a series of filters designed to trap microscopic particles. Common allergens such as pollen, pet dander, dust mites, and mould spores, which are often invisible to the naked eye, can be effectively removed from the air. By reducing the concentration of these irritants, air purifiers help to create a healthier indoor environment, leading to a noticeable reduction in allergy symptoms like sneezing, coughing, watery eyes, and nasal congestion. 

Reviewed by the Healthylife health experts September 2025.