By Jim Rosenthal, CAFS
At last, an air cleaner that is safe, inexpensive, reliable, quiet, and energy efficient. This remarkable product uses the new and advanced Electronic Green Incandescent Technology (ELGIT) system. Tests show that the ELGIT air cleaner reduces viruses, mold, bacteria and other indoor contaminants by 93%! The perfect product for schools, offices and homes – especially in these COVID pandemic times.
- Easy to operate – simple on/off chain
- Quiet – 0 dB (at 6 feet)
- Energy efficient – uses just 60 Watts of electricity
- Safe – certified to produce NO ozone
- Attractive – gentle green glow is perfect for any indoor environment
- Reliable – no moving parts to wear out and no filters to change
- Approved – UL and ETL listed
- Effective – Reduces viruses, mold and bacteria by 93%
An ELGIT air cleaner was tested in a 12’X14′ room with 8′ ceilings. The test lasted a total of 5 days. The first three days were used to establish the baseline particle count. Particle counts included particles 0.5 um and above. A Dylos particle counter was used. All indoor environments have some levels of these three microbials. The 0.5 um range was chosen since it would reflect the vast majority of particles containing viruses, mold and bacteria. After the 3rd day, the ELGIT air cleaner was turned on. Average particle counts dropped from 88,900 particles per cubic foot to 6,400 particles per cubic foot – a 93% drop. Particle counts were slightly lower on the fifth day (5,800 per cubic foot). The test was terminated after the fifth day.
“A 93% decrease in particles containing viruses, mold and bacteria.”
Sounds pretty good doesn’t it? Not unlike the many marketing pieces of the manufactures and marketers of electronic “air cleaners.” The purpose of the above exercise is to show how easy it is to create a good story on a questionable and/or bad product. The important thing to understand is that every statement made in the narrative is TRUE. However, the results are misleading. (Please do not purchase a green shade banker lamp and start using it as your air cleaner.)
Here is how we did it. I tell people that I can produce virtually any outcome in indoor particle count changes if you let me select when I take the particle counts. Indoor particles are created by many different sources including outdoor to indoor particle transfer, people, printers and other machinery, indoor air chemistry, cooking, etc. These sources are often dynamic. As activity continues in the space, new particles are created (or old particles are re-entrained) By the same token, particles are reduced by factors such as mechanical filtration, ventilation and gravity (deposition).
With this information in mind, when would you take the particle counts to achieve the desired results? Let’s go back to the ELGIT example above. The “baseline” particle counts were taken on a Wednesday, Thursday and Friday. There was plenty of activity including people talking and laughing, people movement, office printers, doors opening and closing, particles leaking in from the attached factory, outdoor particles moving indoors, etc.
We turned on the “air cleaner” at the end of the day on Friday. On Saturday and Sunday there is very little activity in the space. No people. No doors opening and closing. No printers. No cooking, Etc. So particle levels start low and very few are added during the day. Just as importantly, gravity (deposition) has a chance to do its work. Almost all of the particles will settle out of the air. Thus it was not a surprise that the particle counts were 93% lower from day 3 to day 4 and 5. It had nothing to do with the ELGIT air cleaner.
Hopefully, this exercise will illustrate the importance of knowing the test procedure in order to evaluate the accuracy of the test results. The “testers” can influence the outcome of the tests. If you see any charts in the marketing literature of the companies that are manufacturing and marketing these electronic or chemical “additive” air cleaners that resemble the one above, be very concerned about their validity for use in buildings. Air cleaners in occupied buildings just don’t produce these kinds of results. You will always see increases and decreases in particle counts as the activity in the building changes. After all, if there is no activity in the building, why would you need the air cleaner? This is also why chamber tests that do not introduce additional contaminants during the test are questionable.
Finally, the results we see for the ELGIT air cleaner support the need for independent 3rd party testing. This testing needs to be peer reviewed to eliminate bias. It is too easy to “design” the results of tests without this independence. It is also why all “company” controlled tests need to be looked at with skepticism and not accepted at face value.