For the testing, two ignition locations were selected near the tip of the fan blade and under the fan hub. The former was selected to maximize fan effect based on fan performance data. The latter was based on observations of Phase One testing. The fan was centered between four sprinklers when sprinkler spacing was 3 x 3 m (10 x 10 ft). In the control mode density area (CMDA) sprinkler tests, where spacing was 2.4 x 3 m (8 x 10 ft), the fan was offset 0.3 m (1 ft) south of center.
[CREDIT] Photo courtesy UL LLC
