How Many Air Purifiers Do I need In a House?

It's no secret that you need more than 1 air purifier in an entire house. But how many air purifiers exactly do I need for clean air? Should I place an air purifier for every room or better breathability? Can I trust the manufacturer's specifications? Wonder no more as in this post, we will guide you through the whole process especially if you are a first-time buyer. We will explain why do you need more than one air purifier, evaluate the room size, what type and size of air purifiers are needed based on your situation. At the end of the post, you should have a clear idea of how many air purifier is required to improve indoor air quality.
Short answer
It depends, but the more the merrier.


How Many Air Purifiers Do I Need?

Most small household would only need 2 air purifiers for their home. First, they would need a large air purifier that has the capacity to cover the living room and kitchen. Second, a small air purifier capable of covering the entire bedroom where a person spends the most time in. Depending on your air purifier CADR and purifying coverage, you might need additional units for room spaces that are not covered. For example, If the air quality of your basement or garage is a big concern, you will need 2 more air purifiers to rectify the poor air condition.

Single or Multiple Air Purifiers?

Having multiple air purifiers for every room is better than purely relying on a single air purifier. The advantage of multiple air purifiers is it can cover more ground therefore more efficient in removing airborne contaminants. The airflow circulation of a single air purifier would often be impeded by walls, doors, furniture, and cabinet. You can purchase multiple, individual air purifiers designed to target specific contaminants. For instance, there are dedicated air purifiers that specialize in removing chemicals, smoke, dust, VOCs, and germ. Another surprising fact is that multiple air purifiers are more cost-effective than a single, whole-house air purifier. A mid-range residential air purifier would cost you around 100-300 dollars while a whole-house air purifier can easily cost you between 2000 to 6000 dollars. A whole-house air purifier is also costlier to maintain as installation or major cleaning requires the service of HVAC specialists. Last but not least, if you opt for a single, whole-house air purifier, you will have very limited options and brands to go with compared with console air purifiers.

Ultimately, if you are on a tight budget and can’t afford multiple units of air purifier, go with a dedicated air purifier so you can move it from room to room. Focus on a room that has the worse air quality or you spend the most time in. Remember, an air purifier is still better than none.

What Size Air Purifier Do I Need?

You should always purchase an air purifier that can at least match the room size you needed it to purify. For example, if you plan to get one air purifier to cover an entire 700 sq. ft. room space, get a large-sized air purifier that has the purifying coverage to support that. If you intend to get 2 air cleaners where each will cover a 350 sq. ft. of space, go with 2 smaller, medium-sized air purifiers.

To choose the right size air purifier, you will need to measure the square footage of the room that needed cleaning. The easiest way is to get the master floor plan and you will have the square footage of the rooms. If you don’t have that, get a measuring tape and measure the 2 perpendicular walls in feet. Multiply the width and length numbers and you will have yourself the square footage of the room. Rinse and repeat the steps to get the rest e.g. living room, kitchen, and dining room. Add those numbers together and you will have an idea what sizes of air purifier is needed to cover your entire home.

So how big an air purifier do I actually need? You can easily identify through the manufacturer’s official recommended room size. The numbers shown are usually in 2 air changes per hour (ACH). ACH is the number of times an air purifier can filter the air in a space hourly. If you are an asthmatic or hyperallergic person, you will need 4 air changes per hour for clean air every 15 minutes. Just divide the official square footage numbers by 2. To find out which model suit you best, visit our curated best air purifier to prevent an asthma attack page.

Another way is to refer to the CADR developed by the Association of Home Appliance Manufacturers (AHAM). CADR or Clean Air Delivery Rate is a metric used to rate the hourly airflow performance of an air purifier. The volume of filtered air is measured in cubic feet per minute (cfm) with 3 separate tests conducted for dust, pollen, and smoke. Take note that not all air purifiers participate in AHAM certified, independent tests. For models that do, you will have a voluntary label called AHAM Verifide printed on the box.

The Different Types of Air Purifiers And Pollutants

The types of air cleaners will determine if you need to place an air purifier in each room. There are few common types of air purifiers in the market: HEPA air purifier, deodorizer, UVGI cleaner, PCO Cleaner, Ionizer, and Electrostatic precipitators. The best option would be a mechanical air purifier that comes with a HEPA filter and a carbon filter. This is because most air cleaners are designed to focus only on a particular set of pollutants. For example, a carbon air purifier can only remove smoke particles and odors. If you have dust concerns, you will need an additional air purifier with a HEPA filter to capture airborne dust.

Not everyone has the same health condition and air quality problems. Even if you and your family member all live under the same roof, everyone might have a different tolerance level against allergens. For example, one family member might have trouble with pet dander from indoor pets while another person might be MCS but have no issue with pets. If you are hyperallergic to dust, dust mite, pollen, mold, pet dander, chemical smoke, bacteria, and viruses, it is best to have an air purifier in each room. Remember, it takes around 30 minutes to 2 hours to clean a room. Having more than one air purifier at home will ensure the indoor air is always clean. With clean, healthy air, there is less chance of you falling sick and allergies being triggered.

Do Air Purifiers Use a Lot of Electricity?

Most air purifiers have a low power consumption rate identical to other smaller home appliances. In fact, some air purifiers consume as little electricity as a light bulb. Even if you leave the air purifier running all day for months, you will not see any major increase in the electricity bill. Do note that some states like Hawaii have higher electricity tiers that will snowball the cost a lot quicker. Look for an Energy Star certified unit if you want the most energy-efficient air purifier.

While there is no harm having multiple air purifiers in a house, surrounding your house with many cheap air purifiers may not be the best solution. The truth is, not everyone needs more than one air purifier. Sometimes having a powerful air purifier and place it at the center of the room would be good enough. But before you blindly purchase multiple air purifiers without knowing what you are getting at, there are many factors to consider. Don't focus on how many air purifiers you need, ask yourself with the following questions:

  • How many rooms in my house and which room do I regularly occupy?
  • What are the total square feet needed for the air purifier to clean?
  • What type of contaminants or air quality problems you are dealing with?
  • Does the air purifier have the right type of filtration and airflow volume to tackle on the indoor pollutants?
  • Can I afford to own and maintain more than one air purifier?



Max Fernandez

A loving father and a dedicated reviewer for airfuji.com with more than 1000 air purifiers under his belt. Max Fernandez is also one of the million patients currently suffering from asthma. Feel free to nudge him if you have any questions.