The BFD curve fitting method of Barnett is adopted to study the compartment temperature-time curves for a series of wood crib fires in an ISO 9705 room. The nominal fire sizes were 0.15 MW, 0.25 MW, 0.5 MW, and 1.0 MW. The cribs were positioned at the corner or the center of the floor of the room. The temperatures within the compartment were measured using two thermocouple trees with 10 thermocouples on each tree; these measured the compartment temperature from floor to ceiling. No flashover occurred during the tests, and the compartment temperature can be well described by a two-zone model. BFD curve fitting was performed for all 20 temperature-time curves in the upper and lower zones of the compartment for each test. The fitting error is evaluated for all tests. This empirical model needs more tests to verify and optimize.