perforated screen for natural ventilation & COD value

[rolo2005]

Hi all,

I'm assessing a room that is naturally ventilated for potential overheating. Outdoor air can enter the room through a fixed perforated screen which is attached to an internal operable window.

There are no default coefficient of discharge values in Marco flo for opening types which have perforated screens, and I wonder if anyone could suggest an appropriate COD value for this opening type.

Thank you for your time.

Rolo