Do Air Purifiers work in Large Rooms? Ultimate Complete Guide

Air purifiers are available in different sizes to provide coverage from smaller to larger areas but you have to be particular about it. Why is that because not all air purifiers are capable of cleaning air after a certain range. Why is that or do air purifiers work in large rooms? Yes, they do work for a large area but how, here is a guide.

Do air purifiers work in large rooms?

Do air purifiers work in large rooms

You might have gone through different air purifiers from desktop air purifiers to the device that offers coverage for a large room. People are of different opinions catering to this concern. 

Some of them find it convenient to place two small to medium-sized air purifiers in a large room to cover a broader area while this technique may work if you want to be extravagant. However, the downside of this method is it will be costlier in terms of device maintenance and also on your electricity bill. 

Many people are not aware of certain guidelines and factors to look for when buying an air purifier for large room. Here are a few tips that will be beneficial for the best purchase. 

Tips for choosing an air purifier for a large room

The first and most important thing while choosing an area purifier is to know the right measurements of your room where it is going to be placed. This will determine whether you need a small device or a large device. 

As we mentioned that some people, to provide more coverage place two devices in a room which is overall quite an expensive approach. That is why, for your ease, here are some tips that you should not 

  • Coverage area

The large room air purifier has a large coverage area which is determined on the basis of two factors; CADR rating and the maximum airflow.

  • Compare CADR

Clean air delivery rating or CADR represents how quickly an air purifier can deliver and filters the air. Always check the device rating that it offers for a specific area. 

An average air purifier has a rating of 200 to 300 CADR.

This unit is constructed by the Association of Home Appliances Manufacturers (AHAM) to judge the efficiency of an air purifier.

According to Environment Protection Agency (EPA), here are the minimum guidelines for a minimum CADR rating according to the room size.

Area in Square FeetCADR Minimum in cubic ft. per minute
100 sq. ft.60
200 sq. ft.130
300 sq. ft.195
400 sq. ft.260
500 sq. ft.325
600 sq. ft.390
  • Maximal Airflow

This simply refers to the highest airflow that the fan speed of your air purifier has. On average, the air purifier has 200 CFM (cubic feet per minute) while any of the best air purifier for large room has 300+ high CFM airflow.

  • An air purifier with HEPA filter

An air purifier for whatever room with the different measurements you are buying, make sure it must have a HEPA filter. This is because it filters the contaminated toxic allergens and pollutants from the air around 99.97% to be precise with an effective method. 

  • Placement of an air purifier

This is indeed a good crucial part of where you want to put your air purifying device. Make sure you place it in the corridors or places with good ventilation. To learn more about location, continue reading, Where to place an air purifier.

  • Filtration system

Here as we are speaking of air purifiers with large rooms so that simplifies the need for a powerful filtration system. For that, it is recommended to go for a device that is offering a minimum of a 3-stage filtration system

This includes a TRUE HEPA filter and an Activated Carbon filter as a must-have filter. 

  • Knowing the noise Level

Air purifiers for large rooms require large devices which means there is a chance of noise from the fan. However, it is true but you can find devices that are comparatively quiet as they offer low dB. 

How to choose the right size of air purifier according to the room size?

Do air purifiers work in large rooms

It is obvious now that the most important thing while hunting for the best air purifier is how much space you want to cover. 

You can find many air purifiers in different sizes and you should know that for a larger room, a heavy-duty air purifier is needed. Similarly, a large air purifier is not a good option for smaller rooms. 

Here is a trick, the best way to judge the air purifier is by knowing its number of air changes per hour. You can find this information in the specification of your device, it could either three or four times in an hour at a minimum. 

For instance, an air purifier can filter an area of 350 sq. ft. 8 times an hour while for a larger area such as twice its size like 700 sq. ft, it will perform the process four times an hour

Since we are discussing some best air purifier for large room, here is our recommendation for your ease.

How big should an air purifier be for a room?

The best way to determine which air purifier you need is the one that has a CADR equivalent to the 2/3rd of the area of your room. For instance, a room with dimensions of 15 ft. by 10 ft. has an area of 150 sq. ft. which means its 2/3rd is around 100 so, you need a device with a 100 CADR minimum.

Our Recommendation for the Best Air Purifier for Large Room

You will have a lot of options when it comes to getting an air purifier. Here is what we recommend based on customer reviews and ease of use. 

Alen BreatheSmart 75i Air Purifier | Best Air Purifier for large room

Alen BreatheSmart 75i Air Purifier


Product Specifications

  • Dimensions: 12 x 19 x 27 inches
  • Weight: 27 lbs. 
  • CADR: 350 
  • Airflow: 347
  • Coverage: 1300 sq. ft.
  • Filters: Pure HEPA, Activated carbon filter
  • Filter Replacement: 12 to 15 months
  • Power consumption: 120 V; 1.8 to 45 W
  • Noise Level:  25 dB to 49 dB

What we liked about Alen BreatheSmart, Pros

  • It is a blend of perfect specifications with CADR 350, 347 max. airflow
  • One of the quietest air purifiers with 25 dB low and 49 dB at the highest speed
  • Has great HEPA filters H13, 2500 hours
  • Durable compared to competitors

What we disliked about Alen BreatheSamet, Cons

  • It is expensive
  • Lacks some smart features

Alen BreatheSmart 75i Review

Speaking of its build, this air purifier is big and heavier as compared to many purifying devices in this price range, yet, it provides ultimate coverage for filtering the air.

It is expensive but every penny is worth spending due to its power and features. It is built to be an outstanding and well-balanced air purifier with a coverage of 1300 sq. ft, 350 CADR, and 347 CFM airflow making it a 1:1 ratio (which is ideal for large rooms).

For 2 ACH (air change per hour) it covers 1300 sq. ft. while for 520 sq. ft. it does so five times. This means this air purifier is safe to use in any kind of room with different dimensions. 

When it comes to its noise, you can count on it as it is one device among the quietest air purifiers with a maximum of 49 dB, this means is can be used in the bedrooms as well. 

Top of all, an air purifier is known for its working and the filtration that it uses, you can totally count on it without undoubtedly. It has H13 True HEPA filters to capture 99.97% microns, making it a medical-grade air purifier. 

With such a CADR rating, this device is ideal for smokers, in the kitchen, basement, and even in the workplace. Further, you will need to change the filters between 12 to 15 months. 

Note: The maintenance of this air purifier or the filter replacement may vary depending upon the air quality of the area you are living in.

Frequently Asked Questions | Do air purifiers work in large room?

  1. Can an air purifier be too big for a room?

The answer is yes. An air purifier works with the coverage areas so similar to being too small for a room, a device can be too big as well. In case a bedroom is 15 x 15 feet, for instance, a small air purifier would be sufficient. For the rooms like the living room or a hallway, you will need a large air purifier. So, make sure you are well aware of your room dimensions.   

  1. Which is the best place for placing the air purifier?

The best place where you can get the most out of your air purifier is by putting it near windows, doors, hallways, corridors, or the place where the ventilation is great. 

  1. Where should I not put the air purifier?

If you feel like your air purifier is not giving its optimal performance then replace the location of your device. Remember that never put your air purifying device near the walls, in the corner, or anywhere blocking the furniture. Make sure there is no upholstery in its way.  

  1. Would a small air purifier work in a large room?

A small air purifier can work in a large room, it will not only take a lot of time but will also cost you a lot when it comes to cost and maintenance. This alone will not be able to clean the air quality for a wide area or for a whole house. For that, you will need to have a whole house air purifier

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