Wind-blown embers are the principal cause of building ignitions. Although the importance of embers (also called brands or firebrands) has been understood for a number of years, the ability to evaluate them in a laboratory setting has been a relatively recent development.

The objective of this study was to clarify the relative importance of vents, including style, type and location of the entry of wind-blown embers. At the time this project was conducted, three vents had been accepted for use by the California OFSM. These vents were incorporated into the experimental design.