History Heat Release

The cone calorimeter represents the third generation of heat release rate equipment at FPL. The first generation of heat release rate equipment at FPL was the apparatus developed by FPL Scientist John J. Brenden in the 1970's. It used the substitution method to measure the heat release rate. It was part of efforts to advocate that the rate of heat released during the combustion of the building materials in a fire was a more meaningful fire safety parameter than the total heat of combustion measured in the oxygen bomb calorimeter.

The second generation of heat release rate equipment at FPL was the Ohio State University (OSU) heat release chamber or calorimeter which was purchased in the 1980's. It is ASTM E906. The heat release rate from the specimen is measured using the sensible heat method, by response of a thermopile. Smoke release rate is also measured by means of optical density measurements of the smoke flow out of the stack. Like the cone calorimeter, the OSU apparatus was used in support of the research programs on fire growth modeling and fire retardant treatments. In later years, we modified the OSU apparatus to also measure the heat release rate by the oxygen consumption methodology. One of the last studies with the OSU apparatus was an investigation of wood-plastic composites. It was replaced with the purchase of the cone calorimeter.

The oxygen consumption methodology used in the cone calorimeter is also used to measure the heat release rate in other test equipment. FPL research has included testing and modeling of the full-scale room-corner test . We have also used the methodology to measured the heat release rate from a wall assembly in the standard ASTM E119 wall test.

In addition to our testing of wood products and other building materials, we have also used the cone calorimeter to evaluate the combustion characteristics of landscape vegetation and Christmas trees. This vegetation data is not included in this depository. This research on vegetation is part of our research program to address the threat to homes and other structures from wildfires (i.e. Wildland-Urban Interface fires).