Air purifiers and dehumidifiers minimize allergens in the room, making it easier for those suffering from allergies and asthma. An air purifier circulates air through a filter that traps air-borne pollutants and irritants like dust, smoke and pollen. A dehumidifier sucks in moisture and reduces the humidity levels in the air, killing mold and microbes that thrive in moisture.

Comparison chart

Air Purifier versus Dehumidifier comparison chart
Edit this comparison chartAir PurifierDehumidifier
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Purpose To circulate and filter the air by trapping dust, smoke and other allergens To reduce the moisture content in the surrounding area.
Humidity levels Can vary Used where humidity is greater than 50%
Types Filter, Ionizing, Ozone generators, Adsorbents, UV light Mechanical /refrigerative, Air conditioners, Adsorption/desiccant, Electronic, Ionic membrane, Makeshift
Application Beneficial to allergy sufferers and asthmatics as they reduce or eliminate dust, second-hand tobacco smoke and other air-borne allergens. Recommended to alleviate allergy by eliminating mold, dust mites and mildew from the air.


An air purifier circulates air through a filter which removes air borne pollutants, like dust or smoke particles, and even pollen, which a dehumidifier cannot. An purifier may prevent mold build-up as it removes the spores from the air. However, because it cannot control humidity levels in a house, excessive moisture can cause mold to return. The video below deconstructs a humidifier to demonstrate how it works:

A dehumidifier's primary function is to eliminate excessive moisture from the air and bring down a room's humidity levels. While this device does not clear or filter air, it does help remove allergens, like mold and dust mites, which thrive in a moist or humid environment. With a humidity level less than 50%, these sources of allergies and asthma wither and die. This is how a dehumidifier works:


Two types of dehumidifiers are typically found in the marketplace: warm mist and cool mist. Regardless of mist type selected, both affect moisture level in the air and lower the level of humidity. Other types include:

The types of air purifiers include:

Health hazards of Air Purifiers

Ozone production is typical for air ionizing purifiers. Ionic air purifiers can produce ozone as an additional feature to eliminate odor. Although high concentration of ozone is dangerous, most air ionizers produce low amounts (<0.05> ppm). Many air purifiers generate some ozone, and in the presence of humidity, small amounts of nitrogen oxide.

The noise level of a purifier can be obtained through a customer service department


Maintaining dehumidifiers requires cleaning all its coils and buckets periodically, and also checking these coils for frost, to improve efficiency.

Air purifiers can be maintained by replacing the filter every 6 months. If the humidifier has plates, they should be washed once a week. To clean the plates, take them out of system and place them in the dishwasher or submerge them in the sink.

How and Where to Buy

After you've decided which appliance is right for you, the next step is what to look for. Watch this guide to buying air purifiers before you make your decision:

The Amazon Best Sellers lists for air purifiers lists the most popular air purifiers in a wide price range.

A guide to buying dehumidifiers:

Amazon's Best Sellers list for dehumidifiers is a good starting point to find one that suits your home, budget and preference.


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