I don't yet do PHRF, and its not that simple. People have thrown the figure
"300" around a lot, but my understanding of PHRF is that a PHRF NW rating
might not coincide very closely with a rating given by one of the other PHRF
organizations, and some have a minimum length on 20', though for PHRF its
18'.
> I seem to recall that LP is one of the factors that is
> considered, but I'm not
> at all sure. And aren't the numbers adjested for local typical wind
> condition? What are the other factors and what is the formula?
> Can you point
> me in the directions of a web site with info?
PHRF-NW webpage is http://members.aa.net/~ths/phrf.htm and they probably
have links to the others. I really don't know much about it, but might get
involved this year.