This question concerns the paper in the NAFI National Fire Investigator newsletter dated Spring 2006. A test burn involving two nearly identical test cells was conducted at EKU in March 2005. The question I have revolves around the time to flashover in the two test burns. The times are quoted as 190 seconds and 330 seconds for the two cells. Depending on how one calculates the difference, this could be a 74% difference in time to flashover. The authors note the two cells differed in ventilation, as evidenced by the time-temperature profiles. The authors state that "The ventilation conditions for the experiments were expected to differ slightly due to the locations of the rooms within the test burn building."
Two identical test burn cells were set up and the time to flashover varies by a very large amount. Was the variation just due to the slight differing of ventilation conditions, or is the flashover time just that variable? How big are the slight differences in ventilation?
Disclosure: I went through one test cell as a participant in the March 2005 fire investigation training that followed the test burns.

John Morse, PE