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If you suffer from asthma or have seasonal allergies, an air purifier can relieve your symptoms by improving the air quality in your home. To help you select the best air purifier for your needs, the This Old House Reviews Team researched the available units on Amazon. Here are our favorite options.
Best Speed Settings: Whirlpool Whispure Air Purifier
With four fan speeds and one sleep mode, this air purifier is customizable to match how much purification your air needs. It has a useful display that shows you the settings as well as the life of the carbon pre-filter and true filter.
Key Features
- Offers four fan speeds, a sleep mode, and a timer
- Purifies up to 490 square feet
- Runs at 43-44 decibels
- Comes with a five-year warranty
What Customers Are Saying
Customers had this air purifier set up in minutes. They said that it was effective at eliminating dust and reducing odors. However, those who weren’t happy with this machine claimed that it was noisy and hot to the touch when it was on.
Quietest Setting: Blueair Blue Pure Air Purifier
Ideal for nurseries, offices, and other spaces where you need quiet, this purifier can remove 99.97% of airborne particles at 23 decibels. It automatically adjusts to real-time conditions to maintain a comfortable air quality, and it has 360-degree air intake to ensure your entire room gets purified.
Key Features
- Offers an auto mode
- Purifies up to 388 square feet
- Runs at 23-53 decibels
- Comes with a one-year warranty
What Customers Are Saying
Positive reviews for this machine said that it was energy-efficient, quiet, and sleek. However, some customers left negative reviews because it didn’t eliminate all unpleasant odors or pet hairs.
Best For Large Rooms: Coway Airmega Air Purifier
Meant for living rooms, primary bedrooms, and other large spaces, this machine has a purifying radius of 1,560 square feet. It filters several types of contaminants, including 99.99% of allergens and 99% of volatile organic compounds.
Key Features
- Offers three fan speeds, a sleep mode, an auto mode, an eco mode, and a timer
- Purifies up to 1,560 square feet
- Runs at 43.2 decibels
- Comes with a five-year warranty
What Customers Are Saying
Customers who were happy with this air purifier said that it was easy to clean and operated quietly. However, unhappy customers wrote that it was bulky. They also said that the lights that indicated the status of the filter and air quality were inconsistent.
Best Digital Display: LEVOIT Air Purifier
This air purifier adjusts to your room’s air quality with three fan settings that are capable of removing dust, pollen, and other allergens from rooms that are up to 900 square feet. It also has an auto mode, a sleep mode, and a timer as well as a touchscreen display to select and show the settings.
Key Features
- Offers three fan speeds, a sleep mode, an auto mode, and a timer
- Purifies up to 900 square feet
- Runs at 27 decibels
- Comes with a one-year warranty
What Customers Are Saying
Customers liked how easy this air purifier was to adjust. They said that it was especially useful for removing floating dust in the air. However, some users were disappointed with how often the filter needed to be replaced.
Best For Germs: Guardian Technologies GermGuardian Air Purifier
This air purifier has four cleaning steps. The HEPA filter captures allergens, while the carbon filter reduces their associated odors. The UV light and titanium dioxide treatment work together to kill germs and eliminate volatile organic compounds.
Key Features
- Offers three fan speeds
- Purifies up to 153 square feet
- Comes with a three-year warranty
What Customers Are Saying
Customers praised this product for being easy to use and quiet. However, customers who left negative reviews often mentioned its cheap build, which caused it to emit a burning smell or stop working altogether.
Buyer’s Guide
Poor air quality can exacerbate allergies. An air purifier removes irritants from the air, improving the air quality and preventing respiratory issues. In our guide below, we’ve outlined important factors to consider about an air purifier to ensure that you get the right model for your home.
Needs
If you suffer from allergies or asthma, choose an air purifier with a HEPA filter that can remove 99.97% of most airborne particles that are 0.3 microns or larger. For chemical sensitivity, look for a model that eliminates odors and volatile organic compounds.
Size
To choose the right size air purifier, calculate the square footage of the room you want to purify by multiplying its length by its width. Select a unit with a coverage rating that’s greater than or equal to this measurement.
ACH Rating
Air change per hour (ACH) reflects how often an air purifier filters the entire volume of air in the treatment space each hour. For example, an air purifier with an ACH rating of four pulls air through the machine and cleans it four times per hour. If you’re particularly sensitive to allergens, a higher ACH rating can be useful to constantly keep the air around you clean.
Settings
Most air purifiers offer high, medium, and low fan speeds to match your purifying needs. You can also find an auto mode that adjusts the fan based on the air quality it senses, a sleep mode that keeps the fan quiet when you’re in bed, and a timer that runs the fan for a set number of hours.
Service Indicator
If you want to ensure that your purifier is working to the best of its ability at all times, look for one that has a service indicator light. This tells you when it’s time to clean or replace its filter.
Noise Level
Air purifiers can be noisy, especially when they operate on their highest setting. If you’re planning on leaving the appliance in your bedroom or home office, look at the decibel level. For a unit that sounds like subtle white noise, stay below 45 decibels.
Types of Air Purifiers
There are two types of air purifiers.
Portable
In this review, we focus on portable air purifiers. These devices are designed to clean the air in a single room. Not only are they smaller and easier to move throughout your house, but they’re also more energy-efficient and affordable than their whole-home counterparts.
Whole-Home
Whole-home air purifiers attach to existing heating or air conditioning equipment. These use more energy and are more expensive than portable models. However, they filter a larger area.
Types of Air Purifier Filters
Different air purifiers use different filters. Most machines come with at least one air filter, but you’re responsible for purchasing any replacement filters.
Pre-Filter
A pre-filter captures large particles that enter the device. It’s smaller and cheaper than a HEPA filter. Check this filter every few months, and replace it when it’s dirty.
Second Pre-Filter
A second pre-filter catches the smaller particles that the first pre-filter didn’t. This middle filter also targets odor molecules.
HEPA Filter
HEPA filters remove up to 99.97% of airborne particles. Though effective, they’re expensive to replace.
How Does an Air Purifier Work?
Your air purifier uses a three-step process to filter the air in your home.
- The air purifier sucks in air from the room—During this step, the fan pulls air into the machine and passes it through the pre-filter. The pre-filter captures most of the large airborne particles, such as dust and dirt.
- The air filters through the second pre-filter—Before hitting the HEPA filter, the air and any remaining particles and odors go through the second pre-filter.
- The air goes through the HEPA filter and cycles back into the room—In this last step, the air passes through the HEPA filter before the fan pushes it back into the room.
How To Get the Most Out of Your Air Purifier
Though air purifiers can be a big investment up front, there are simple steps you can take to save money in the long run. We explain some of them below.
- Clean the house regularly—The more contaminants you remove from your home, the less work your air purifier has to do. Dust your tables, desks, and shelves every week, and vacuum your floors at least twice a month.
- Use candles sparingly—Candles emit carbon dioxide, which your air purifier has to filter.
- Invest in an energy-efficient purifier—Units with an ENERGY STAR certification may be a bit more costly, but they use less energy, saving you money over time.
- Change the filter every time it gets dirty—You may be tempted to change the filter less often than the manufacturer recommends to save money. We advise against this. Operating an air purifier with a dirty filter reduces its efficiency and can lead to mechanical malfunction.
- Purchase washable filters—Replacement filters can cost anywhere from $50 to $500. By using a reusable, washable filter, you won’t have to buy a new one every time it gets dirty.
Frequently Asked Questions
Can an air purifier eliminate my allergies?
Air purifiers can’t completely stop you from developing allergies, but they can go a long way in reducing both the severity of your symptoms and the amount of time you have to deal with them. When you’re shopping for an air purifier for allergies, be on the lookout for one with a HEPA filter that eliminates common pollutants that cause allergies, such as pollen, dust, and pet hair.
How much maintenance does my air purifier need?
The frequency at which you need to clean or replace your air purifier’s filter largely depends on the type of filter, the manufacturer of the unit, the size of the room, and the quality of the air. However, you should change most filters every six to eight months.
How often do I need to use my air purifier?
Air purifiers are designed to run for a continuous period of time. You can opt to leave your air purifier on all day, although that can lead to higher energy and electricity costs. Many purifiers come with a timer or auto mode. If that’s not the case with your purifier, try running it for eight to 12 hours a day.
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We recommend products in each review using an intensive research process, spending hours combing through the best available models on Amazon. For a product to make our list of top picks, it must hold a solid sales record on Amazon, have consistently positive customer reviews, and offer unique features, among other factors. After narrowing down our list of recommendations, we conduct additional research and sometimes in-person testing to ensure that the products meet our standards. Once we conclude the research phase, we craft a well-rounded, user-friendly article that includes our recommended products and additional information to help homeowners like you make the right purchase.
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