Compare Air Purifier Criteria
10 separate rating factors are utilized to compare air purifier against air purifier. The top possible rating score is 100 points. Each rating factor has a maximum point value listed below.
I use a combination of objective criteria (labeled O) and subjective criteria (labeled S). Objective means it is supported by factual data. Subjective is more of an experiential rating factor. Subjective depends on the expertise of the reviewer. Combining both objective and subjective is the best way to compare air purifier against air purifier.
At the end of this page you will find additional factors that were considered before final rating scores were given.
Rating Factors:
1) Value – 20 pts(S/O) – This is a somewhat complicated measure. The cost is an objective measurement. Cleaning Ability is a combination of objective fact and subjective feel. Cleaning ability will be ranked on a scale of 1 to 10 with 10 being the best. Two factors will define cleaning ability, What is removed (#3 below) and how well. What is removed contributes 5 pts as follows 15pts (from #3) = 5pts, 12 pts = 4 pts, 9 pts = 3 pts, 6 pts = 2 pts, 3 pts = 1 pt. The “how well” factor will be a multiplier. not well = .5 pts, well = 1 pt, very well = 1.5 pts, extremely well = 2pts. Value = Cost divided by Cleaning ability. <100 20 pts, <110 18 pts <120 16 pts, <130 14 pts, <140 12 pts, <150 10pts, <160 8 pts, <170 6 pts, <180 4 pts, <200 2 pts.
2) Quality – 15 pts(S) – Quality defines good products. Fit, finish, and workmanship up to 5 pts, cleaning medium(s) and/or cleaning technologies up to 5 pts, setup and ongoing support material up to 3 pts, and intangibles up to 2 pts.
3) What is Removed – 15 pts(O) – An air purifier is only as good as what it removes. Partial points are given in any category for sub par results. Particles >0.3 microns 1 pt, Odors and Gases 3 pts, VOCs 2 pts, Basic Microorganisms 3 pts, Particles <.03 microns 2 pts, Advanced Microorganisms 2 pts, Any other additional 1 pt.
4) Yearly Operating Costs – 15 pts(O) – Included would be standard consumable items like filters and UV lamps as well as electricity costs. Averaged over a 5 year period. <£50 15 pts, <£100 12 pts, <£150 9 pts, <£200 6 pts, <£300 3 pts.
5) Warranty – 8 pts(O) – A good warranty period generally shows that a company has faith in their products. <1 year 1pt, 1-<2 years 2 pts, 2-<3 years 4 pts, 3-<5 years 6 pts, 5+ years 8 pts.
6) Maintenance and Cleaning – 7 pts(S) – How easy it is to change filters, clean the purifier, and do other routine maintenance. Easy 7pts, mostly easy 5pts, some easy, some not 3 pts, not as easy as others 2 pts, most not easy 1 pt.
7) Manufacturer Years in Business – 5 pts(O) – The time a company is in business speaks for itself. Companies do not stay in business if they do not make effective products. <1 year 1 pt, 1-<5 years 2 pts, 5-<10 years 3 pts, 10-<20 years 4 pts, 20+ years 5 pts.
8) Look and Feel – 5 pts(S) – How the unit looks and how easy it is to use. Looks great and very easy to use 5 pts, looks good and easy to use 4 pts, looks ok and usable 3 pts, questionable looks and/or questionable usability 2 pts, questionable 1 pt.
9) Set-Up Time – 5 pts(S) – This is the time it takes to unpack, browse the set-up materials, place and start running. <10 min 5 pts, <20 min 4 pts, <30 min 3 pts, <45 min 2 pts, <1 hour 1 pt.
10) Noise Level – 5 pts(O) – Two factors form this rating, noise level on lowest an on highest setting. Low: below 35dB 2 pts, below 45dB 1 pt. High: below 35dB 3 pts, below 55dB 2 pts, below 70dB 1 pt.
Additional factors:
Area Coverage: The square footage that a purifier is recommended for. There are different ways to compute and compare. This does need to be taken into account when purchasing a purifier. Look for this information in the summary for each purifier review.
Air Change Per Hour (ACH): This applies only to passive technology. It is a measure of how many times a purifier can exchange the air in a given sized room per hour. The purifiers’ ability to “suck” the air through the technology (filters or other) is rated. This factor is best associated with cleaning ability and does find its way into my rating. Not all purifiers publish this information.
Clean Air Delivery Rate (CADR): This factor is calculated by AHAM (The Association of Home Appliance Manufacturers). It gives a square footage measure indicating how much air is cleaned for three different pollutants: tobacco smoke, pollen, and dust. When AHAM have tested the air purifier they will a marked with the e AHAM Certified seal and CADR numbers. The higher the CADR rating, the more effective the air purifier is against that pollutant. The biggest drawbacks are that this rating does not factor well with all types of purifier and that only 40 or so manufacturers have paid their “dues” to be included in the certification. These numbers are included in the basic specifications for each purifier when given by the manufacturer. They are an additional way to compare certain models and are taken into account in my reviews.
I truly believe this rating system will give you a great way to compare air purifier against air purifier.