Snow Drift for a large AHU
Snow Drift for a large AHU
(OP)
I understand that ASCE 7-05 requires using the "windward" 0.75Hd snow drift against a roof projection 15' or longer. What about the opposite side of the AHU? Should you evalute the loading with 0.75Hd drifts occurring on both sides of the AHU at the SAME time?
The reference is section 7.8. The Figure 7-7 is not refered to in section 7.8. But it shows windward and leeward drifts occurring at "steps".
The reference is section 7.8. The Figure 7-7 is not refered to in section 7.8. But it shows windward and leeward drifts occurring at "steps".






RE: Snow Drift for a large AHU
I believe that the intent is to say that the wind will come from any direction and deposit the snow on all sides, however, due to the 15' width dimension, the snow on the leeward side will be shielded and not be removed by the wind coming from the opposite direction.
RE: Snow Drift for a large AHU
If I understand your post, you are saying that there are potential windward drifts being accumulated on each side. One day the wind blows snow from the west and the next day it blows from the east. Is this what you meant?
RE: Snow Drift for a large AHU
RE: Snow Drift for a large AHU
RE: Snow Drift for a large AHU
I am trying to justify placing an AHU on an existing roof if I can.
RE: Snow Drift for a large AHU
What you are proposing is how I would do it.
DaveAtkins