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Air purifiers and dehumidifiers can transform your indoor air quality, but choosing the right one depends on your needs.
Whether you're tackling mold, dust, or improving overall air health, this guide will help you decide which machine is best for your home.
Key takeaways
Air purifiers versus dehumidifiers: Key comparisons
An air purifier removes airborne pollutants like dust, smoke particles, and pollen. It also prevents mold build-up by eliminating spores from the air.
Multiple studies have indicated that air purifiers with HEPA filters can remove up to 99.97% of all fine particles, including viruses and bacteria.
A dehumidifier’s primary function is to eliminate excessive moisture and reduce humidity levels.
It doesn’t filter the air but can help remove allergens like mold and dust mites that thrive in humid environments.
Related article: Top rated dehumidifiers and air purifier combos
Header | Air Purifier | Dehumidifier |
|---|---|---|
Purpose | Circulates and filters the air, trapping particles such as dust, smoke, and allergens to improve air quality | Designed to lower the humidity levels in the air by removing excess moisture from the surrounding area |
Humidity Levels | Varies | Air dehumidifiers are typically used in areas where the humidity levels exceed 50% |
Types | Filter, HEPA, Ionizing, UV light, Ozone generators | Air conditioners, mechanical or refrigerator, desiccant, electronic, ionic membrane |
Application | Remove impurities from the air | Reduce moisture from the air |
Dehumidifiers versus air purifiers: When to use each?
For removing mold
An air purifier can help remove mold spores from the air while you work on physically removing the mold from surfaces.
If the source of your mold problem is high humidity, purchase a dehumidifier to reduce moisture levels and prevent mold growth in the future.
Here's a table I've made to help you determine the best relative humidity level for your space:
Goal | Below 40% | 40% - 50 % | Over 60% |
|---|---|---|---|
Best for total home comfort | |||
Ideal for allergy sufferers | |||
Manage asthma symptoms | |||
Avoid respiratory illnesses | |||
Stop the spread of viruses | |||
Negate static electricity | |||
Discourage bacteria and mold growth | |||
Fight dust mites |
If you don’t have a mold problem but want to ensure that mold spores and other contaminants do not enter your indoor air, then an air purifier can be a good investment.
Air purifiers can remove up to 99% of mold spores in the air, but are not a one and done solution, as they cannot eliminate visible mold.
Verdict: Use both an air purifier and dehumidifier for mold
For allergies
If you’re suffering from seasonal and environmental allergies, an air purifier can help remove allergens like pet dander, smoke, bacteria, and pollen from the air.
An air purifier with a true HEPA and carbon filter can capture 99.7% of contaminants, effectively combating most allergens.
The best air purifiers for allergy sufferers typically have multiple stages of filtration, including a pre-filter, carbon filter, HEPA air filter, and UV light.
While I would first try an air purifier for allergies, a dehumidifier can also be beneficial.
According to the Clinical Research Clinic, home humidity levels above 50% can trigger allergens.
Related article: The best whole home air purifiers
Verdict: Choose an air purifier to reduce allergens
For babies
As a parent, you want the best for your kids, so you choose both an air purifier and a dehumidifier in their room. An air purifier can help keep them healthy by removing harmful contaminants like dust, mold, and pollen.
A dehumidifier will maintain the appropriate humidity levels in the room to prevent dry skin and other discomforts.
Some air purifiers also come with diffusers, allowing you to use essential oils to create a calming and soothing environment for your children.
If you choose to use a diffuser around your child, make sure to follow the best safety practices for use of essential oils.
Verdict: Both a dehumidifier and air purifier are recommended for nurseries
For dust mites
If you’re struggling with dust and dust mites in your home, an air purifier can help remove them from the air.
Look for an air purifier that features a true HEPA filter that can capture particles as small as 0.3 microns and a dust prefilter that can capture larger particles like dust and hair.
This will help ensure your indoor air is clean and free of irritating particles that can cause respiratory problems.
However, it should be noted that if high humidity is your issue, a dehumidifier will help as well. The National Center for Healthy Housing has stated that dust mites thrive in areas where the the humidity levels are above 55% to 75%.
Verdict: An air purifier is a first line of defense against dust mites.
For smoke
I recommend using an air purifier to effectively remove tobacco or cooking smoke.
Air purifiers have also been proven to help with asthma and allergy symptoms caused by wildfires.
Look for models with a high smoke CADR (Clean Air Delivery Rate) number that indicates the machine’s effectiveness in eliminating smoke particles from the air.
In addition, opt for air purifiers that feature a carbon or charcoal filter, which can help to remove smoke odors.
Choosing models with true HEPA filters is also beneficial as it can capture smoke particles and other pollutants as small as 0.3 microns.
Related article: Air purifiers for removing harmful VOCs
Verdict: Air purifiers are a major defense against smoke
For basements
Basements are prone to excess moisture when the surrounding soil is wet, leading to mold growth and unpleasant odors. A dehumidifier can help reduce the basement’s humidity level to an acceptable range.
Once the humidity is under control, you can use an air purifier to eliminate mold spores, dust, or bacteria that might have accumulated in the air.
Again, look for an air purifier with a HEPA filter and activated carbon air filter to effectively remove these pollutants from your basement.
Verdict: Dehumidifier and air purifier
How dehumidifiers work to remove moisture
Dehumidifiers are effective at reducing indoor humidity to the recommended 30-50% range. I like to keep my indoor humidity at 40%.
Dehumidifiers draw in warm and moist air and pass it over a cold coil, causing the water vapor to condense into water droplets.
These droplets are then collected in a container or drained continuously through a hose. The machine then releases drier air back into the room using a fan.
Certain models may include a humidistat that monitors and adjusts the humidity levels.
However, it’s important to note that not all dehumidifiers have this feature, so be sure to check the specifications before purchasing. Some models only have a hygrometer, which reads the humidity level.
| Hygrometer | Humidistat |
|---|---|---|
Purpose | Measures humidity levels | Controls humidity levels |
Measurement capability | Gives real-time readings | Monitors and regulates based on set point |
Control capability | No direct control function | Can adjust devices |
Accuracy | High accuracy for readings | Moderate accuracy, focused on regulation |
Typical use | Monitoring indoor humidity | Automatic regulation of HVAC devices |
Cost | Low | Mid to high |
Here are a few of the most common types of dehumidifiers and how dehumidifiers work:
ACLAB Note:
Make sure the humidity levels are in the ideal range. Air that is too dry is equally bad for your health and belongings. Make sure you have a hygrometer to measure the air humidity at all times.
How air purifiers clean air
Your indoor air can contain harmful contaminants that should be removed as quickly as possible.
Air purifiers work by pulling in polluted air and filtering out impurities. The best air purifiers I’ve come across use filters like HEPA filters and activated carbon filters.
Others use methods like electrostatic precipitation or UV-C light to remove contaminants.
Here are a few of the most common types of purifiers and how they work:
Related article: Are ionic air purifiers safe?
ACLAB Note:
The efficacy of UV light, ionizers, ozone generators and other filterless air purifiers is debatable. For best results, choose to go with mechanical air purifiers that have different several air filtration stages including HEPA filtration.
FAQs
Can you use a dehumidifier and air purifier together?
You can use a dehumidifier and an air purifier together.
Dehumidifiers reduce humidity levels to improve indoor air quality, while air purifiers remove harmful particles from the air to provide cleaner, healthier air.
Can you buy a combo all-in-one air purifier and dehumidifier that does both?
You can buy combo dehumidifiers and air purifiers. These options can be the best of both worlds for some consumers. They are also relatively affordable.
How do air purifiers and dehumidifiers compare in terms of price?
In terms of price, dehumidifiers generally cost slightly more than air purifiers since they contain a compressor.
How do air purifiers and dehumidifiers compare regarding maintenance?
Air purifiers generally require less maintenance than dehumidifiers.
Air purifiers require filter replacements every few months, while dehumidifiers require more frequent cleaning and water removal.
