The most crucial factor to consider before purchasing an air purifier is the size of the room where you intend to use the unit.
You’ll almost inevitably ask yourself, “What size of air purifier do I need?”. This is such a crucial question that you want to pay attention to.
The size of your room determines the size of the air purifier you need. And ultimately, the coverage capacity of the device in terms of the CADR rating.
This is essential for asthmatics and people with allergies who need almost perfect air quality to breathe effectively.
Now, if that’s you, not to worry.
In this article, you’ll learn how to get the air purifier sized for your room.
Can an air purifier be too small for a room?
Absolutely yes. When it comes to air purification, an air purifier that’s too small will work inefficiently in large rooms.
This is because the air purifier is underpowered, and its Clean Air Delivery Rate is not enough to clean to cover the whole room.
But how small is “too small’?.
For example, using an air purifier meant to purify a room of up to 80 square feet in a living space of about 500 square footage can be considered too small.
Obviously, this will give a poor performance. However, to significantly improve your air quality, you may have to run the unit for an extended period.
Unfortunately, this would mean incurring more costs in terms of power consumption. And you don’t want that.
More so, the air in the room won’t be optimally pure as it should be in the correct sized room.
Therefore, it is best to measure your space correctly to get the best air purifier with accurate square footage for your room.
This will help prevent you from incurring additional costs.
Alternatively, you could opt for a large air cleaner with a higher CADR rating to remove air pollutants in small and huge rooms.
Can you use a large air purifier in a small room?
Yes, you can. A large cleaner can work well and produce almost the same performance as in a small room if used correctly.
The size of the air purifier is less important than its features for addressing the specific airborne contaminants you’re targeting to remove from your air.
But technically speaking, a large air purifier may not be ideal for small spaces.
And using it will come with some downsides.
So this is what I mean. A large air purifier is designed with more coverage capacity, so it consumes more energy.
So in a small room, you can think of it as a waste of energy.
Another limitation is that a large air purifier will take up much space in a small room, which is fine if you are OK with it.
But in a small room, you can not guarantee a silent operation. It’s more likely to produce more noise output in a small space than in a large one.
Also, the sound may interrupt your sleep if you’re a light sleeper. So getting an air purifier that is adequately sized for your room makes a lot of sense.
How to calculate CADR for air purifier
The CADR (Clean Air Delivery Rate) rating is the value that tells you the volume of clean air a purifier can provide within a specific amount of time.
The CADR metric is a vital specification you must understand if you want an air purifier that can effectively clean your space.
This is because an air purifier can have incredibly cool features. Still, if it has a low CADR rating, it may be less effective in meeting your needs.
So let’s dive into how to calculate it…
To get air to calculate the CADR rating of an air purifier, you need to consider two factors—the size or volume of the room and the Air Changes per Hour (ACH).
- The room’s size: You can get the size of your space in a few simple steps. Firstly, measure the length of the room in feet. Similarly, measure the width in feet. Now, multiply these dimensions to get the Square footage. Next, get the height of your ceiling, then multiply it by the square footage. This gives you the volume in cubic Feet of the air in your room.
- The Air Changes per Hour (ACH): ACH is the number of times an air purifier can exchange the air inside a room with a specific size. For example, a room with a 2 ACH rating means air is filtered twice. The higher the ACH rating, the more effective the air purifier. So this ultimately depends on your preference or needs. For example, if you suffer from allergies or asthma, it’s recommended that you go for with 5 ACH rating. However, the 2 ACH rating is ideal for healthy persons.
Steps for Calculating the CADR Ratings for Air Purifiers
- Measure the length, width, and ceiling height of your room.
- Multiply the three dimensions in feet to get the volume of the room.
- Decide the number of Air Changes per Hour (ACH) you need.
- Multiply the volume of the room with the ACH to get the size of the air purifier. This is the CADR rating expressed in CFH (Cubic Feet per Hour).
- Lastly, divide the CFH by 60 to convert it to CFM (Cubic Feet per Minute). Most manufacturers specify the CADR rating of air purifiers in CFM.
How do you size an air purifier for a room?
Now that you’ve known how to calculate the Square footage of your room and the CADR value for air purifiers, you can use that to get an air purifier that suits your room size.
Here’s an example of a practical application of how to size an air purifier for your room.
Example: Let’s assume you live in a 1000 sq. ft. room with an eight ft. ceiling height. And because you suffer from allergies, you need an air purifier that can change the air in your room 5 times per minute. So how do you size the air purifier for the space?
First, calculate the volume of the room using the formula above
Volume = 1000 x 8 = 8000 cubic feet.
Next, multiply the volume by your desired ACH. In this case, 5.
CADR rating (in CFH) = 5 x 8000 =40000 CFH
Finally, Convert CFH to the recommended metric, CFM. Just divide by 60.
CADR rating = 40000/60 = 667 CFM.
To clean the room 5 times per minute, you need an air purifier with a CADR rating of 667CFM.
Air Purifier Room Size Calculator
The above calculation may seem complicated. However, there’s an easier and more simplified way to get an air purifier for your room size.
And that’s an Air Purifier Room Size Calculator. This digital calculator calculates the Clean Air Delivery Rate (in CFM) without stress.
So you can save your time working out the calculation manually.
The calculator comes with three sliders. Each for the Square footage of the house, the height of the ceiling, and the Air Changes per Hour.
So you only need to slide each slider to whatever number you want.
The calculator automatically comes up with the CADR rating of the air purifier you need for your room.
Learn Metrics has an Air Purifier calculator for room size, which can accurately calculate and automatically display the air purifier’s CADR rating you intend using your room size.
This way, you can determine the unit’s effectiveness before purchasing.
In addition…
You can also check their Air Purifier size chart…The chart gives you various sizes of rooms and their corresponding CADR rating for 2 ACH and 5 ACH.
So to test, you can use Learn Metrics HVAC Systems Air Purifier room size calculator for the above example; insert the room area by sliding the area slider to 1000 sq. ft.
Next, move the height slider to 8ft and the ACH slider to 5.
The calculator automatically calculates and displays the CADR rating of the air purifier needed for the room, which is 667 CFM.
How Proper Air Purifier Placement can Improve Performance Based on The Size of The Room
Proper placement of an air purifier is crucial for optimal performance…
Especially when it comes to the size of the room.
For smaller rooms…
To ensure maximum air purifier effectiveness, it’s best to place it in the center of the room…
With no obstructions from furniture or walls.
This allows for better circulation and capture of pollutants from all corners.
For larger rooms…
It’s recommended to place the air purifier near the source of pollutants…
Such as a smoking area or a pet’s sleeping spot.
Or, you can use multiple air purifiers strategically placed throughout the room.
By considering the size and layout of your room, you can improve the effectiveness of your air purifier…
Also provide cleaner, healthier air for you and your family.
Read More: Air Purifier Placement.
Conclusion
An air purifier could have all the best features in the world and still perform poorly in a given size room.
To prevent this from happening, ensure you purchase an air purifier that is correctly sized for your living space.
And this involves calculating the CADR rating for the air purifier you want to buy.
Fortunately, an air purifier room calculator can help you work out this effortlessly.