By: Elizabeth Tran

November 25, 2021

Share on twitter
Share on facebook
Share on pinterest

How Many Air Purifiers Do I Need?

Indoor air pollutants are 2 to 5 times higher than outdoor levels, which can be a startling fact when you think about how much time we spend indoors. But it makes sense when you think about it. Indoor areas aren’t as ventilated, we’re using ovens, colognes/perfumes, we’re tracking in dirt from outside, we have more products (like furniture), and so on.

That’s why having an air purifier should be a given.

But when you start looking at how to get clean air in your homes and offices, you’re going to quickly come up against a big question — how many air purifiers do I need?

Do you need air purifiers for every room, or could one big unit do the job? Should your air purifier always be on or just when you’re in the room? What if you have pets or are sensitive to allergens?

In this post, we look at those questions in detail, focusing on how many air purifiers you need by considering your room size and your needs.

How To Know If I Need Additional Air Purifiers?

In a perfect world, it would be great to have one inexpensive air purifier that could easily purify your entire home. But, unfortunately, that is not the case.

Some people might think, “Oh, I’ll buy cheap air purifiers for all rooms.” Well, they’ll be the reason behind the skyrocketing energy bill and could break down in a year.

The key to finding how many air purifiers you need is to consider a few factors and calculations. If you hate math, we have created a table of how many additional air purifiers you need.

Calculate The Amount of Indoor Air

You need to start by calculating the volume of indoor air. Use this simple equation:

             Volume = Indoor Area (sq ft) x Ceiling Height (ft)

For example, the indoor air volume calculation for your 1,200 sq ft home and 8 ft ceiling height will be:

1,200 sq ft x 8 ft = 9,600 ft3

Therefore, you need to clean about ten thousand cubic feet of air about 4 times for effective purifying. Essentially, that means the air purifier needs to clean 9,600 ft3 x 4 = 38,400 ft3 of air per hour.

The Capacity of Your Air Purifier

It is essential to understand that every air purifier has a unique capacity. An average air purifier cleans about 200 cubic feet of air in a minute. It means that the unit can clean 12,000 cubic feet per hour.

Given that you have to clean 38,400 ft3 of air per hour, you will need more than one quality air purifier for your home. Having multiple air purifiers is better than relying on one unit as they can efficiently remove airborne contaminants.

The Number of Air Purifiers You Need

We know that an average air purifier can clean 12,000 cubic feet of air. To find how many units you need, use this simple equation:

For your home, the calculation will be:

Total Number of Units = Total Volume of Air To Be Cleaned / Air Purifier Capacity

38,400 ft3/ 12,000 ft3 = 3.2 air purifiers

Air Purifier Table According To Home Size

For a house bigger than 800 sq ft, it would be best to purchase more than one air purifier. If budget is not a problem, a good idea would be to invest in air purifiers for every room of your home.

The following table can help you determine the right number of air purifiers suitable for your home:


1,200 sq ft






1,600 sq ft






2,000 sq ft






2,400 sq ft






2,800 sq ft






3,200 sq ft





Number of Air Purifiers Depending On Rooms

Now you know about the square footage that correlates to the amount of air an air purifier needs to clean and the unit’s capacity. So, let’s make it a step easier by breaking down your home into areas that require an air purifier.

For open living, kitchen, and dining, you need at least 2 air purifiers. Get an air purifier with a heavy activated carbon filter, especially for the kitchen, as it will absorb cooking odors.

You’ll need a low-noise, powerful air purifier for the master bedroom and baby room to ensure the unit absorbs as many contaminants as possible. For the basement, you’ll need a low-maintenance air purifier that can work along with a humidifier to prevent the growth of mold.

If anyone smokes in your house, their room might require more than one purifier.

Single or Multiple Air Purifiers: Which Option Is More Economical?

Instead of getting a whole-house air purifying unit, it would be best to have multiple air purifiers. After all, a mid-range unit could cost you around $100-$300, while a whole-house unit can easily set you back $2,500-$6,000.

Moreover, a whole-house unit is not easy to maintain and requires a professional cleaning service. Homeowners who are on a tight budget need to consider multiple air purifiers.

Even if purchasing 3 or 4 air purifiers upsets your budget, you could get one high-quality unit and easily move it from room to room.

What Size Air Purifier Do I Need?

Instead of buying an underpowered air purifier, you need to consider four sizes in which these units come:

Small Air Purifiers: These units are ideal for small, personal spaces. You should get one for a room up to 200 square feet.

Medium Air Purifiers: These units are ideal for rooms between 200 and 400 square feet. You could get 2 or 3 units depending on the usage.

Large Air Purifiers: These units are best for rooms between 400 and 1,200 square feet. If buying one unit exceeds your budget, you could get 2 mid-range units.

Whole-House Air Purifiers: These units are installed in the HVAC system and are worth the money. However, this unit is a sound investment only when you can afford it without breaking the bank.



How much electricity does my air purifier use?

The good news is that an air purifier does not use a lot of electricity. Its energy use is similar to a small to medium-sized TV. However, it can have an impact on your electricity bill if it is overworking or malfunctioning.

A small-sized air purifier for a big room can overwork. Moreover, you don’t need a big air purifier for a small space; it’ll just consume more energy.

Can I run my air purifier all day?

Yes, manufacturers recommend running an air purifier all day. It is because they are specifically designed to run and clean the air constantly. So you can turn them on even when you’re out of your home.

How long does an air purifier take to clean the air?

On average, an air purifier takes about 30 minutes to 2 hours to clean all the air in the room. Just how quickly it purifies the air depends on the quality of the unit, filter quality, power setting, and ACH (rate of changes per hour).






Add a Comment

Your email address will not be published. Required fields are marked *


How to Clean a Toaster (in 8 Steps)

May 15, 2023

Cleaning a toaster is important to ensure it functions properly and to remove any accumulated

Bonavita 1L Digital Variable Temperature Gooseneck Electric Kettle vs INTASTING Professional Electric Gooseneck Kettle

May 13, 2023

Comparison of Bonavita 1L Digital Variable Temperature Gooseneck Electric Kettle and INTASTING Professional Electric Gooseneck

Tuft and Needle Mint Hybrid Mattress Review (2023)

May 11, 2023

The Tuft & Needle Mint Hybrid mattress is a thoughtfully designed bed that combines the

Shopping Basket

Subscribe to our newsletter