calculation of free air area on a ventilation grill Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[wmaxwell]

I have been told/ordered to increase the ventilation area to the housing of our gas central heating boiler room. I presently have two grills of 8000mm squared - that is 80 sq cm. I am required to fit a grill 141 sq cm at the top of the access door to the boiler room and a grill 282 sq cm at the bottom of the door. What sizes of grill will provide the above free area?

[toneyt]

you could put 2 of the ones at the top and 4 at the bottom