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Clean Air Delivery Rate (CADR) – What Should You Know?

When you enquire about different air purifiers available in the market for investment purpose, you will come across a term called Clean Air Delivery Rate. What is it and how is it determined? Let us find out here:

What is CADR?

CADR, which is the short-form of the Clean Air Delivery Rate is actually a numerical value assigned to any air purifier on the basis of independent tests conducted for the Association of Home Appliance Manufacturers (AHAM). This association has been measuring the CADR of air purifiers right from 1980s. This rate is actually an indication of the volume of filtered air delivered by a portable unit. In other words, it can be stated as a uniform standard with the help of which potential buyers can easily judge the quality of the air purifier.

With a wide range of choices available for the buyers to choose from, such a rating standard is highly appreciable. The Association of Home Appliance Manufacturers has stated that this rate of valid irrespective of the particle removal technology used by the manufacturer. This means that regardless of whether a manufacturer has used an ionizer or an HEPA filter, this rate can be evaluated for judging the quality of the purifying unit.

Definition given by United States Environmental Protection Agency:

According to this agency, ‘The CADR is an evaluation of a portable air cleaner’s delivery air that is free of any contamination that is expressed in cubic feet per minute. For instance, if a portable air purifier has a CADR of 250 for dust particles; it is believed that it may bring down the dust particle levels to the similar concentration as it would be reached by augmenting 250 cubic feet of clean air every minute.

Determination of CADR:

Generally, an air conditioning unit is given CADR Rating via a relatively easy to understand method known as ANSI/AHAM AC-1 standard that measures the requirements of CADR. Here is the process used for evaluation:

  • The purifying unit is initially placed on a testing chamber of 1008 cubic feet.
  • Before activating the unit, the level of contamination present in the room is initially evaluated.
  • Then, the unit is activated for 24 minutes and during this period the level of contaminants in the room is periodically measured again and again.
  • At the end, the reduction in the contamination level is compared to their natural decaying rate.
  • Once the evaluation is over, the evaluators proceed to give the unit its rating.

How about the accuracy of CADR?

This rating has a history of nearly 30 years and with the increase in the manufacture of air purifiers these days, it has widely spread. Even, reputed organizations that work beyond the air purification niche have adopted this rating, inclusive of the Federal Trade Commission and Environmental Protection Agency. So, no reason can be stated for not to believe in CADR, but it is better to use certain measure of caution in selection of the right air purifier.