7 ms·

Don't things have to be built to ASHRAE 62.x per many building codes already? * https://www.ashrae.org/technical-resources/bookstore/standards-62-1-62-2 https:

• enragedcacti 3y ago
  I'm not familiar with the history of ASHRAE but it seems like the older versions were well below a 4+ air change rate, in addition to other serious issues[1]. The the most stringent spec as of 1999 for a 1000ft2 classroom with 30 people had a required supply airflow of 450 cfm which gives you only a theoretical 2.7 ACH assuming 10ft ceilings and perfect air distribution. The CDC targets are just a suggestion at this point but they are likely just the first step in retrofitting existing buildings. [1] Ventilation Through The Years: A Perspective https://www.aivc.org/sites/default/files/airbase_12483.pdf https://www.aivc.org/sites/default/files/airbase_12483.pdf
• sokoloff 3y ago
  It would be up to each AHJ (authority having jurisdiction) to adopt ASHRAE 62 into their building codes and most have not. As far as I can tell, neither Massachusetts nor my city have incorporated ASHRAE 62 into their codes. (ASHRAE 90.1-2013 is required in MA for commercial buildings, but those relate to energy efficiency, not air quality.)