Air purifier vs dehumidifier — we explain the difference and why you may need both

A woman pressing the on button on a white air purifier
(Image credit: Getty Images)

While proper ventilation is the key to tackling issues like damp and mould in our homes; air purifiers and dehumidifiers play a crucial role in enhancing the overall quality of the air we breathe every day. 

But while there is some crossover between air purifiers and dehumidifiers, the main functions of these appliances vary. 

Below, we take a closer look at the differences between the two, and examine why you may require a combination of both an air purifier and a dehumidifier to improve your home's air quality.

Air purifiers vs dehumidifiers – what's the difference?

At first glance, air purifiers and dehumidifiers might seem to fulfil similar roles in improving indoor air quality, but they serve different functions.

Air purifiers are designed to filter out airborne pollutants, allergens and odours, ensuring the air you breathe is cleaner. 

Dehumidifiers, in contrast, reduce excessive moisture in the air, which can lead to problems like damp, mould and mildew

Why would you use an air purifier?

Young woman using digital tablet to set up a home air purifier.

(Image credit: Getty Images)

Air purifiers operate by trapping a variety of airborne particles. These include common irritants like dust and pollen, making them ideal for homes in urban settings or for individuals suffering from allergies and asthma.

An air purifier might be the ideal solution if you or your home are troubled by the following:

  • Persistent allergic reactions.
  • Smoking fumes.
  • Bad odours. 
  • Pet dander.
  • General concerns regarding indoor air pollutants.

Certain air purifiers are designed to trap volatile organic compounds (VOCs) and other potentially harmful chemicals that may be present in household cleaning products, paints or building materials. Other models – equipped with UV-C light – claim to kill airborne germs and bacteria, reducing the spread of illnesses in the home. 

The Honeywell Premium True HEPA Air Purifier, from Appliances Direct, is a popular model of air purifier. It contains an activated carbon filter to reduce odours in the home, as well as an ioniser to remove mould spores from the air. 

It's worth noting that an air purifier is not designed to treat damp. Dampness is related to poor home ventilation and the level of moisture in the air, which an air purifier does not affect.

Why would you use a dehumidifier?

modern dehumidifier in home office

(Image credit: Duux)

Conversely, a dehumidifier will not only help treat damp in your home, it can also solve condensation and even dry your laundry. Rather than trapping air particles, a dehumidifier works by extracting the moisture from the air.

For mould issues, a dehumidifier – like the Probreeze 20L Premium Dehumidifier – is generally more effective than an air purifier. Mould thrives in moist environments, so reducing excessive humidity levels in your home with a dehumidifier can help prevent mould growth. While an air purifier can filter mould spores from the air, it won't address the root cause of mould. 

When would you need both appliances?

In certain situations, your home environment might benefit from the combined use of both an air purifier and a dehumidifier. If, for example, you have high humidity levels in your house, as well as pets who shed their fur everywhere, you may see the benefit to using both. 

Using an air purifier and a dehumidifier together can improve the overall air quality in your home. The dehumidifier reduces moisture and prevents mould, while the air purifier cleans the air of particulates and allergens. The Meaco low energy dehumidifier and air purifier is a good example of a unit that does both.


Can you put an air purifier and a dehumidifier in the same room?

Yes, you can. However, it's important to position them strategically to prevent them from interfering with each other's airflow. Ideally, they should be placed at least 3 - 5 feet apart. This separation allows both devices to efficiently circulate and treat the air in its vicinity without impacting the output of the other. 

Can you buy a 2-in-1 air purifier and dehumidifier?

Can you use an air purifier with a humidifier?

Unlike a dehumidifier, a humidifier is designed to introduce moisture into the air in order to combat dry conditions. While you wouldn't use a humidifier and a dehumidifier in the same environment, you can combine an air purifier with a humidifier. 

Gabriella Dyson
Assistant Editor

Gabriella is Homebuilding & Renovating's Assistant Editor. She is a DIY enthusiast and a lover of all things interior design. She’s spent the past decade crafting copy for regional publications, award-winning architects, and leading UK homeware brands. 

She has a particular passion for historic buildings and listed properties, and she is currently in the process of renovating a Grade II-listed Victorian coach house in the West Country. At Homebuilding & Renovating Magazine, Gabriella is responsible for curating the magazine's home case studies and regularly contributes to the Homebuilding website.