Calculate the Air Purifier Needed for Your Room Size

Choosing the right air purifier for a home or business involves many factors including whether it has a HEPA filter or not, whether it has UV protection or possibly whether it has carbon filtration. However, most shoppers don’t consider how much air it will clean and how quickly. The better air purifiers will have a CADR (Clean Air Delivery Rate). You can use this number to calculate whether the purifier is powerful enough to clean your home or business. By knowing this number and your square footage, you don’t risk leaving airborne particles in the air. Below we will walk through how to calculate your room size so you can find the perfect air purifier for your home or office.

Step 1: Measure Your Room Size or the Space Where the Unit Will be Placed

The first step is determining the size of your room where you need the air purifier. This can be done by calculating the square footage of the room. To calculate square footage, simply multiply the room’s length by its width.

For example, if your room is 12 feet long and 10 feet wide (assuming an 8 ft ceiling):

12 ft x 10 ft = 120 square feet

Once you have this number, you’ll need to check the coverage area of potential air purifiers to ensure they can handle that amount of space. Air purifiers are typically rated for room sizes, so it’s easy to match a model to your space’s size. The better air purifiers will have a CADR (Clean Air Delivery Rate) so you can easily compare. Please note that CADR is measured based upon a standard 8 ft ceiling. If your ceilings are higher, you will need to make some slight modifications to account for the extra square footage.

Step 2: Understanding CADR (Clean Air Delivery Rate)

CADR is a metric established by the that rates an air purifier’s ability to remove different type of particles from the air plus provide a recommended closed room size in square feet. The particles they test for are dust, pollen, and smoke. The higher the number is for each particle the faster the unit cleans the air.

A good way to think about this in relation to your home is that your air purifier’s CADR should be roughly two-thirds of the room’s square footage. For example, if you have a 150-square-foot room (10 ft x 15 ft), aim for a unit with a CADR of at least 100 for optimal performance. Of course, lots or homes feature an open floor plan, so you need to get a unit that covers a larger space. Another example might be a house where the living room, breakfast room and kitchen are all part of the same space. In this case the square footage could be 3x the previous example or 450 square feet. So, in this case, the unit would need a CADR of at least 300.

Step 3: Consider Ceiling Height

As mentioned earlier, be sure to check the ceiling height. CADR is calculated based upon an 8-foot ceiling. Some homes have ceilings that are 9 ft, 10ft and even vaulted that are much taller. If your room has higher ceilings, you will need to account for the additional volume of air that the purifier will need to clean. One way to compensate for this is to opt for an air purifier with a slightly higher CADR rating or one designed for larger spaces.

Step 4: Other Factors to Consider

When choosing an air purifier, it’s also important to consider the following factors: Association of Home Appliance Manufacturers (AHAM)

• Number of Air Changes per Hour (ACH): ACH refers to how many times the air purifier can filter the entire room in an hour. A higher ACH means the air is being filtered more frequently. This is incredibly important during seasons with higher infection rates or for people with allergies and asthma.
• Types of Pollutants: Some air purifiers are more efficient at removing specific types of pollutants like dust, pet dander, or smoke. If you have other concerns, such as mold, viruses, cigarette smoke or pollen, look for units that excel at filtering those particles.
• Filter Type: Many air purifiers use HEPA filters, which are highly effective at trapping microscopic particles. Don’t get fooled by the term HEPA-like. HEPA-like filters may not capture the small particles and therefore may not resolve your symptoms.
• Other Factors: There are also air purifiers that include activated carbon filters that help remove odors, gases, and VOCs (volatile organic compounds).

Step 5: Choose a Model that Covers More

While you may be tempted to buy an air purifier that fits your room size exactly, it’s often better to select one with a bit of extra capacity. Why you ask? Let’s consider that the air purifier is used to clean the air during normal conditions. However, there are times when pollution is higher, infectious diseases are more prevalent and/or there are times of the year when pollen is significantly higher. During these times, you may want to move the air quicker, to keep you safe. For the rest of the time, you can keep the purifier at a lower maintenance level.

Step 6: Maintaining Air Purifiers

Once you’ve selected the right air purifier, regular maintenance is essential to keep it functioning efficiently. The good news about a high-quality filter is that it captures airborne particles. Much like the furnace, the filter needs to be changed periodically so that it can capture more particles in the air efficiently. Be sure to follow the manufacturer’s guidelines for when to replace the filter. Please note also, that it is a good idea to keep the unit in a central location where it can circulate air throughout the room effectively.

Final Thoughts

Choosing the right air purifier goes beyond the filter and other bells and whistles. The purifier should be sized to your room to ensure the air is cleaned efficiently. By calculating the square footage, understanding the CADR rating, and considering additional factors like ceiling height and air changes per hour, you can select the perfect model for your needs. Remember, investing in a model with a little extra capacity can make a significant difference in performance, keeping your air cleaner and your living space healthier.