How to Choose the Right Size for an Air Purifier? (A Definitive Guide)

Choosing the right size air purifier for your needs can be daunting. How do you know which is best? How many square feet should it cover? How much noise will it make? How expensive is it going to be to maintain this machine over time? What are the benefits of an air purifier, anyway?

We’ll answer all these questions and more in this post about How to Choose the Right Size for an Air Purifier?.

What are CADR and ACH?

CADR is short for “Clean Air Delivery Rate”, and it’s a number that indicates how much air an air purifier can clean. The higher the CADR, the more it will clean the air in your home.

AER is short for “Air Exchange Rate”, and this is a number that indicates how many times per hour an air cleaner can process enough air to remove allergens and pollutants from the room it’s in. AER is measured as cubic feet per minute (CFM).

If you want to get the most out of your air purifier, here’s a simple way how: Follow this formula. CADR x 1.55 = Square footage or rooms in which it will be used (i.e., living room). So, if we have an 8×8 ft room size and our CADR rating is 70, then.

Following our calculations would give us approximately nine sq ft for efficiency purposes.

Some people worry that an air purifier with low CADR ratings will not clean their home, but this isn’t true. It’s just a matter of how long it’ll take the machine to entirely blow out all particles from your space and surrounding areas- you may want to start by picking one which has higher CADR values if possible.

If there are varying counts between devices in terms of smoke/pollen or dust removal rate (i.e., some units have better performance than others), look for something small enough to not weigh down on power consumption while large rooms require more effort.

ACH is a unit of measurement that tells you the number of air changes per hour. This rating can be found on most purifiers, and it’s important because if there are less than 2x ACH (or 4x for asthma patients), then your room won’t get enough cleaning time which could make them ineffective at filtering out all those pesky allergens.

The best possible solution is opting for one with an ACLH overcharge; this ensures better filtration and quicker recovery from vaping sessions- good news considering how quickly these types work up emissions.

Types of Air Purifiers?

Air purifiers come in four different sizes, each type suited for a room of the specified size. The measurements are given as square feet, and there’s one to fit everyone’s needs.

They are:

Small air purifiers are ideal for individual places and spaces up to 200 square feet.

Medium size is perfect between 200-400,

 while large models work best if you have 1,500 or more available.

For the whole house – meaning every nook in your abode needs clean air, too – get an electronic model rated at least 1500 CFM (cubic foot per minute).

How to Choose the Right Size for an Air Purifier?

You should measure the square footage of your room to choose the proper size air purifier. Then pick a unit that can meet or exceed this specification for the cleanest possible breath. This choice is essential in ensuring everyone’s safety from pesky germs and other irritants harmful enough to cause illness when breathed into one’s lungs.

Nowadays, most people are buying smaller models than they used before due to their asthma-inducing allergies, so don’t forget about those needs.

Here’s a step-by-step guide to determining the ideal size of air purifier for your space:

Step 1:

Determining Where You Want to Place the Air Purifier

The first and most crucial step in choosing an air purifier is determining where you want the device. Determine if a single room or multiple rooms are needed and for all areas inside your house that need cleaning up (like under furniture). Once clear on these points- it will be much easier to narrow down different products available so they can best serve your specific needs.

Step 2:

Calculating the Square Footage of the Room

After deciding to purify your home, the next step is figuring out what size space you want. If it’s just one room, this will be easy because all that needs doing in order for square footage purposes are two measurements from perpendicular walls; 10 feet by 12 feet equals 120 square ft of total area.

If you want an air purifier that will clean the air for many connected rooms, add up the measurements of each room separately. For example, if two adjoining rooms are 120 square feet and 80 square feet in size, the total area is 120 + 80 = 200 square feet.

If you’re attempting to figure out how big an air purifier should be for an entire home, the easiest approach is to check your purchase papers.

The entire square footage of your house should be included in the house plan. If you can’t discover this information easily, go outside and measure the length and width of your outside walls.

Multiply the result by the number of levels in your house.

For example, if the outside area is 1,200 square feet and you have a two-story home, this equals 2,400 sq. ft. (1,200 x 2 = 2,400 sq. ft.)

Step 3:

Compare the Air Purifier’s Square Feet Rating with the square footage of the house.

The final step in the process is to match your air purifier specifications with specific room size. Air Purifiers come with an installed square footage rating, but this isn’t always enough for you – it depends on what type and how big of space needs cleaning.

When choosing between models, be sure that their features meet all requirements (even if they’re slightly over).

For example: If one model says it’s good at 400 sq ft. At the same time, other only works up until 350′, then take note because by now, there’ll already have been some dirt accumulated and clearing these areas could become more complicated, so get the one that fits your exact needs.

How to Clean Different Room Sizes with One Air Purifier

Sometimes it’s not feasible for you to buy an air purifier for each room on your property, which means that if there are different models, they must work in various rooms.

If this is the case, it’s a good idea to buy an air purifier with adjustable fan speed so you can adjust the unit as needed.

The more powerful models have several speeds and work on larger areas best. In contrast, others require being attached to a window so they can use their own power source instead of drawing from your home’s electricity – which is useful for smaller spaces.

Also Read: What is a Stabilizer Free operation in AC and Refrigerators?

FAQs: How to Choose the Right Size for an Air Purifier?

How much should I pay for an air purifier?

An air purifier should be able to clean the air you breathe in your home. The cost of an air purifier depends on what features you want. The higher the quality of the filter, the more expensive it will be.

What are the best air purifiers?

There are many brands of air purifiers on the market, but the best air purifier is the one that will clean the air you breathe in your home.

What is the best way to choose an air purifier?

The best way to choose an air purifier is to read reviews online.

How do I know if I need an air purifier?

If you have a pet or have allergies, you should consider getting an air purifier.

How often should I change the filters?

It would be best to change the filters at least once a month.

Can I Use Multiple Air Purifiers in One Room?

Yes, you can use multiple air purifiers in one room. However, it is important to keep all air purifiers in the room evenly spaced to avoid any dirty air from one purifier affecting the performance of another.

How Many Air Purifiers Do I Need?

There is no definitive answer to this question as it depends on the home’s size, layout, and needs. However, an estimate is that a home with an average-sized bedroom and living room will need between one and three air purifiers.


If you’re wondering how to choose the right size air purifier, this article should have been able to answer all your questions. Follow the steps outlined in our guide and get a unit that suits you.

Let us know if we forgot anything or answered any questions for you’ll down below- do not hesitate at all to reach out with what else is on your mind by clicking “Add Comment” near the bottom of the post 🙂

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