1/ #ONTed, Memo B14 says for non-mechanically ventilated classrooms, must size portable HEPA units & consider noise.
For equity with their mechanically ventilated counterparts, typical elementary classroom during instruction should add 400 CFM CADR & under 50 dB(A) total.
For equity with their mechanically ventilated counterparts, typical elementary classroom during instruction should add 400 CFM CADR & under 50 dB(A) total.
2/ A new portable classroom or newer school (~20-25 years) will have *more* than this minimum ventilation capability, AND lower noise, AND *additional* built-in filtration (like MERV-13 filters) So, this is an entirely realistic goal, that still doesn't fully achieve equity.
3/ The Ministry recognizes the higher risk in unmasked (kindergarten) situations. To address elementary unmasked time (lunch!) in non-mechanically ventilated classrooms, capability should be double, so up to 800 CFM CADR, with *total* room noise under occupational safety limit.
4/ These recommendations come from ASHRAE Std 62.1 standard for ventilation, and various standards for acoustics as outlined by @ETFOeducators document Noise in Classrooms. etfohealthandsafety.ca/site/noise/
5/ Where does that put us with one of the most common air cleaners on the market?
Austin Air HM400 is nominal 400 CFM *without the filter*, and with the filter provides:
High 250 CFM & 65 dB(A)
Med 125 CFM & 55 dB(A)
Low 40 CFM & under 40 dB(A)
Austin Air HM400 is nominal 400 CFM *without the filter*, and with the filter provides:
High 250 CFM & 65 dB(A)
Med 125 CFM & 55 dB(A)
Low 40 CFM & under 40 dB(A)
6/ The Austin Air units are good for other contaminants because of the large carbon filter component, as this detailed independent video review covers:
7/ For student equity with their peers blessed with the advantage of a mechanically ventilated classroom WITH additional high-MERV filtration AND extra outdoor air provision, one typical HEPA unit isn't going to cover it for a non-mechanically ventilated classroom.
8/ I'm sure my friend @joshpascoe would be eager to sell more units in Ontario to meet the requirements - run multiple units on lower speed for the noise component, with total capacity for more cleaning power during unmasked activities.
9/ Another example: Dufferin-Peel Catholic District School Board issued a tender (T2020-102) for industrial air scrubbers with noise on maximum speed of 79 dBA.
10/ So be aware, if sized for absolute minimum equivalency for mechanical ventilation without regard to noise, the total classroom noise may exceed occupational limits.
https://twitter.com/DavidElfstrom/status/1422907767594049539?s=20
11/ As the Ministry of Education advises, work with qualified professionals, like Professional Engineers @O_S_P_E and Industrial/Occupational Hygienists who can do the necessary calculations and measurements.
If not, are board staff practicing engineering without a license?
If not, are board staff practicing engineering without a license?
12/ Finally, demand that @fordnation fund proper long-term capital improvements outlasting an election cycle to properly @Fix_Our_Schools!!
13/ See?? No professional oversight, result: THIS
https://twitter.com/Fuzzy_Pumpkin92/status/1426593254418653188?s=20
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