Mike,
The report ?Infiltration Modeling Guidelines for Commercial Building Energy Analysis? from Pacific Northwest National Laboratory might be of interest to you. See equation 5 on p. 10. The report is available at http://www.pnl.gov/main/publications/external/technical_reports/PNNL-18898.pdf.
Sincerely,
Keith Swartz, PE | Senior Energy Engineer
Seventhwave
608.210.7123 seventhwave.org
