Draw SA$,$ RA$,$ OA$,$ and EA in different colors $($e$.$g$.,$ SA: Green, RA: Orange, OA: Blue, EA: Red$).$

you may want to open the file in PowerPoint or other drawing programs to edit the image.

$4-2)$ How many supply diffusers do you see?

$4-3)$ How many return grilles do you see?

$4-4)$ Which devices or systems are used for thermal comfort and indoor air quality?Cunningham Hall $($IIT$)$