When you shop for air purifier, there are many number on the box of the air purifier that you will find confusing. Each air purifier will have a different set of number that will indicate the feature of that air purifier. For instance, one air purifier may have a measurement of the size of the room that the air purifier can service, another air purifier may have the CADR of the air purifier, and yet another air purifier may show case the power of the air purifier without provide a measurement of the amount of air that the air purifier move.
The measurement of the amount of air that the air purifier move is referred to as CFM, and it is the single most important measurement of air purifier feature that you should of understand when you are shopping for an air purifier. If you dont understand the CFM of the air purifier, you may end up purchasing an air purifier that do not effectively clean the air in your space. CFM is an acronym that stands for cubic feet per minute.
What CFM Means and How to Choose an Air Purifier
Air purifiers use this measurement to indicate the amount of air that the air purifier move per minute. Additionally, CFM will help you to determine the size of the air purifier that you need to purchase because the size of the air purifier should match the size of the room where the air purifier will be used. If the air purifier do not move the amount of air that is present within your room, the air will not be cleaned, and the air will cycle within the room without being clean.
In order to calculate the CFM that you need for the air purifier in your room, you must calculate the total volume of the air in your room by multiplying the length of the room by the width of the room by the height of the ceiling. After you calculate the volume of air in your room, you will need to multiply that volume of air by the number of air changes per hour that you need (achieved through calculating the needs of the individuals in your room), and dividing that number by 60 to calculate the CFM that you need in your air purifier to ensure your air is properly clean. Air changes per hour, or ACH, measure the number of times that clean air changes the air in a room during the hour.
The ACH of a room can be measured by calculating the number of times that the air in the room is replaced with new air per hour. The ACH changes according to the need of the individuals in the room who must have their air clean. For example, if there are young children in the room that requires high level of air cleaning (due to allergies, for instance), the ACH will be higher than in a room with a person that do not require as much air cleaning.
Because ACH changes, the CFM that is required to achieve the desired ACH will also change. The higher the ACH, the higher the CFM that is required in the air purifier. When air purifier manufacturers list the coverage area for an air purifier, they often use two air changes per hour in their calculations of the coverage area.
Two air changes per hour is typically used to represent the amount of air that is changed for odor control in an area. Yet two air changes per hour is not nearly enough for allergy sufferer to have their air properly cleaned. Thus, to achieve a higher ACH, a higher CFM will be required for the air purifier.
Additionally, the height of the ceilings in your room may factor into the CFM of the air purifier that you purchase. Most air purifier manufacturers calculate the coverage area of their air purifiers as if the ceiling height in the rooms are eight feet. If the ceilings in your rooms are more higher than eight feet, you will require an air purifier with a higher CFM rating.
Another measurement for air purifiers is CADR, and it measures the amount of the air that pass through the filters is clean air. Thus, an air purifier can have a high CFM rating yet a low CADR if the filters are not very efficiently at cleaning the air. To ensure that you purchase the best air purifier for your home, you should check both the CFM and CADR of the air purifier models that you are considering.
Finally, purchase an air purifier with a CFM rating that is twenty to twenty-five percent higher then your calculated required CFM. The reason for this recommendation is because air filter become filled with the particulates that are removed from the air in your room. As the air filter becomes filled, the CFM of the air purifier will drop.
Thus, if you purchase an air purifier with a higher CFM than the one that you need for your room, the air purifier will remain at a medium setting that is quiet than at maximum speed. Thus, understanding the CFM specifications for air purifiers will allow you to make a purchasing decision for your home that is not based off the claim of air purifier manufacturers, but one that is based upon performance.