Fire Safety Test Furnace Characterization Unit

Abstract

In standardized fire safety tests such as IMO Res. A 754 (18), ASTM E119, or ISO 834, the furnace temperature is controlled to a standard time-temperature curve [1,2]. The assumption is made that thermal exposure in these tests will be repeatable and can be described by the measured furnace temperature. The significant variations that occur in test results indicate this assumption is not well founded. Fire safety test results are influenced by both the temperature of the furnace and by heat transfer in the furnace. The heat transfer depends not only on the furnace temperature and how it is measured but also on the design of the furnace and the test unit. In developing engineering models of fire performance and performance-based codes, there is a need to understand both aspects of thermal exposure — temperature and heat transfer. To begin to address these problems, the U. S. Coast Guard's Research and Development Center authorized a study of furnace tests. The study documented important factors in current test methods that lead to large uncertainties in the fire safety test results. To attempt to understand and reduce these large uncertainties, the Coast Guard authorized the development of a Furnace Characterization Unit (FCU). The FCU was built, calibrated using a special electric heater at Sandia National Laboratories, and then used to characterize temperature and heat transfer in a large, gas-fired test furnace at Underwriters Laboratories. This paper reports the results of this multi-year effort.