Natural Ventilation

[Mech]

2009 IMC

For natural ventilation . . .

402.2 Ventilation area required. The minimum openable area to the outdoors shall be 4 percent of the floor area being ventilated.

In the case of a window, is this net area (free area of the screen) or gross area (size of the window frame that is movable)?

Thanks

 

[Coug Dad]

I would not take a reduction for the screen.

 

[north star]

& &

Mech,

I would interpret the 4% opening requirement to be,

when the window is fully raised / opened, ...that area

of the window unit that is actually allowing air

movement through it, should be a minimum of 4%

of the floor area in which that window is installed.

* * *

 

[fatboy]

I wouldn't want to try and calculate reductions in the field for various screening materials.......openable area.......move on.

 

[ICE]

Don't forget the fly **** that's stuck in that screen.

 

[fatboy]

And the paint.....and dust.........oh, in this neck of the woods, quite often..........it's missing altogether!