Thread by @smartrestartaps

1/ We have results from Illinois Institute of Technology lab that is evaluating electronic air cleaners.

They tested the Blueair 211 units (which APS bought).

Results are disappointing to us.

📌 Project:
built-envi.com/portfolio/air-…
📌 Report:
built-envi.com/wp-content/upl…

2/ There was some inaccurate information being put forth that these machines were not ionizers, because they were not listed by the California @AirResources Board as ionization devices.

But these machines do indeed have an ionizer. 👇

3/ The use of additive and electronic air cleaning devices, often marketed with HEPA in the name although they ARE NOT HEPA cleaners, has come under scrutiny this year.

motherjones.com/politics/2021/…

4/ Scientists have raised concerns about some kinds of air cleaners because they may emit a lot of ozone.

California @AirResources Board checks this out, and we FOIA'd documents. The Blueair filters that APS got do not create ozone, according to public records provided by CARB.

5/ Scientists have also raised concerns about how shooting ions into the air can create chemical reactions with what's in the room — that result in "gas-phase organic compounds (VOCs, aldehydes)."

Here's a list of byproducts that scientists have looked for, that are possible:

6/ This new testing showed that ionization is critical to Blueair's Clean Air Delivery Rate, because it causes things to stick to the filter.

The filter didn't perform so well without the marketed "electrostatic" energy making particles more clingy. (Shown in charts.)

7/ Specifically, when the ionization component was disconnected inside units, these electronic air cleaners performed 44% worse for the very smallest particles.

Univ. of Florida 👩‍🔬 found smallest particles contain infectious virus, so these need ionization turned on to catch 🦠.

8/ These results mean that APS can't just disable the ionizer component, even if parents & teachers are worried about volatile compounds and possible byproducts of this technology.

We had hoped this might be OK, but they'll have to use the units as is to fight COVID-19.

9/ Replacement filters will likely cost APS as much as real HEPA filters.

But "True HEPA" filters would have removed 99.97% of dust, bacteria and particles <0.3 µm, w/o any ionization needed. Top experts like @CorsIAQ strongly recommended buy only HEPA.

tinyurl.com/IsItHEPA

10/ The testing also presented an independent review of the certified CADR (Clean Air Delivery Rate), a measure of how fast and well they filter.

CADR for smoke, dust, and pollen particles during normal operation (with ionizer enabled) were estimated to be 285, 309, and 389 CFM.

11/ In the independent university test, these portable filters that APS got performed about 19% worse than we expected.

As a result, we have likely UNDERESTIMATED the amount of uncontaminated air our kids will have in many classrooms.

12/ Parents and teachers asked APS NOT to purchase any air cleaner with ionization.

Blueair's marketing material says it uses "electrostatic filtration" and distances itself from "air cleaning techniques based only on ionization."

That's the only time ionization is mentioned.

13/ More to Read:
📌 iit.edu/news/air-clean…

📌sciencedirect.com/science/articl…

📌onlinelibrary.wiley.com/doi/epdf/10.11…

📌sciencedirect.com/science/articl…

14/ More to Read:

📌 workinmind.org/2021/04/14/ele…

📌cdc.gov/air/trailerstu…

15/ We tried to convince our VA senators @MarkWarner and @timkaine to please write STRONG guidelines so schools would spend $$ on products that are proven, like True HEPA air cleaners.

It didn't happen. 😭

https://twitter.com/DrEricDing/status/1365698797075070987?s=20

16/ It's ironic we were watching out for this stuff, but now we have 2,000+ air cleaners, shooting a very high amount of negative ions into our classroom air.

They will remove virus in the air, and that is the biggest priority right now.

But they may hurt IAQ in other ways.😞

17/ APS should not more of these units and switch to a different model of True HEPA cleaner, as suggested in March.

Please don't double-down. Start a serious effort to replace what you've got with True HEPAs. A replacement filter is 30% of the cost of a new HEPA cleaner.

@threadreaderapp unroll

FYI @jeremychrysler I know we talked about disabling ionizers in these units but it’s not a good idea if someone is depending on the unit to filter during pandemic and depends on the advertised CADR. May want to consider a note of caution for safety on your YouTube video! See 🧵