For projects that include operable windows, which of the following outdoor air contaminants determine how window use should be managed?

For projects that include operable windows, which of the following outdoor air contaminants determine how window use should be managed?
A . PM2.5
B . PM10
C . Ozone
D . Carbon monoxide

Answer: A

Explanation:

According to Feature A07: Operable Windows, part 3 of the WELL Core requirements, the project team must monitor outdoor levels of ozone, PM10, temperature and humidity, and discourage occupants from opening windows when outdoor air either (i) exceeds ozone levels of 51 ppb or PM10 levels of 50 μg/m³; (ii) has a temperature of 8 °C [15 °F] above or below indoor set temperature; or (iii) has a relative humidity above 60%1. PM2.5 is not explicitly mentioned in the feature, but it is a subset of PM10 and has similar health effects, so it is reasonable to assume that it should also be considered when managing window use.

Reference: = Operable windows | WELL Feature Library – v2