Given the sheer volume of air purifiers in today's market, it is really difficult to set each one apart because more or less they all have similar features. So in order to build a set of standards for these products, the Association of Home Appliance Manufacturers (AHAM) came up with the notion of CADR.
CADR is the abbreviated form of Clean Air Delivery Rate and it is a measure of the air purifier's efficiency in removing the pollutants present in the air. In simple terms, it is the amount of contaminant-free air that being delivered by the product. It is calculated in terms of cubic feet per minute (CFM). AHAM suggests that you should choose an air purifier whose CADR when multiplied by 12 is greater than or equal to the size of your room in terms of cubic feet. But my suggestion would be to choose the one whose capacity is greater than the size of your room because that way more air can be purified within less amount of time.
Too much of technical drilling, eh? Let's get down to what we really need to understand.
Different air purifiers have different CADR ratings and it is comprised of three important values which are for pollen, dust and smoke. These ratings in general, show how each of the air purifiers deals with the air contaminants. As a point of fact the higher the CADR value more is the efficiency of the purifier. One thing that has to be noted here is that the CADR value generally makes sense for portable air cleaners. This is the reason why these ratings are never mentioned for a large whole house air purifiers.
How to make a choice based on CADR?
So as we already know that CADR for dust, smoke and pollen are provided for all the purifiers. Each of these contaminants is not of the same size. What I mean by this is that the defined particle size range for smoke is 0.09–1.0 micro meters, for dust it is 0.5–3 microns and for pollen it is 5-11 micro meters. As the smoke particles are of the smallest size their rating is the first to be one displayed which is then followed by dust and pollen in accordance to particle sizes.
Let us compare the Clean Air Delivery Ratings of Fellowes AP-230PH model with Fellowes AP-300PH. As shown in the image below, clearly ratings of the AP-300PH model are better when compared to its counterpart.
For instance, if you are looking for an air purifier which can effectively deal with dust and have zeroed in on the above two, then I would definitely suggest Fellowes AP-300PH model because it clearly has a higher CADR for dust when compared to the other purifier.
So if dust is the issue for you over smoke and pollen then you should be looking for a cleaner that has higher CADR rating for dust.
Now that you understand how the CADR works, put your newly learned knowledge into action the next time you look to purchase on of these.
So why do we need to trust the AHAM?
Well AHAM actually represents all the home appliances producing manufacturers present in the United States and this association is duly recognized by ANSI and also supported by the EPS Service Parts Act. So yes, they are recognized by the legislature of the United States. They also develop technical guidelines for many of the appliances in order to create a level playing field in terms of standards.
Rest assured, I can clearly say that these are the guys you need to trust when it comes to the safety of the appliances we use in our daily lives.
I can understand that this topic was a bit difficult to grasp because of all those confusing technical terms. But hey, this is something you don't want to miss because this is how the efficiency of an air purifier is measured. I can assure you that once you have a basic grip over this topic you will definitely find it easy to pick the right product for your home.