Knowing that I would be at NSF International headquarters in Ann Arbor, Michigan, for a Standards Committee meeting, I called my friend Dave Orton on NSF’s staff and asked for a tour of its new testing facilities for roof drains. Dave was kind enough to accommodate me by providing a great tour.
To say the least, the test rig was impressive. NSF has started testing to ASPE/IAPMO Z1034. This is the standard used to establish flow rates through a roof drain at various ponding depths.