Development and Commissioning of a Calorimeter for Testing the Thermal Performance of Luminaires

Abstract

The goal of this project was to design, construct and commission a calorimeter for testing the thermal properties of state-of-the-art luminaires. The calorimeter was built to serve as a testing facility in the Lighting Research Laboratory at the University of Kansas School of Engineering. The calorimeter was designed to approximate a room to achieve testing results that could be applicable in the actual applications. The calorimeter is a highly insulated box (1990 mm x 740 mm x 1915 mm) equipped with six temperature sensors to measure temperature at the air intakes, exhausts and in the center of the calorimeter and two anemometers to measure the air flow rate running through the ceiling cavity and room cavity. Luminaires will be installed in the calorimeter for testing their thermal performance. With a two-cavity-layout and a material of choice separating the two cavities, the calorimeter allows for the one-dimensional analysis of heat distribution. Using data from the temperature sensors and the air flow rate, the heat released by the luminaires to the ceiling cavity and the room cavity can be calculated respectively. Due to its mobility, the calorimeter can be used in different environments such as a temperature-controlled room. Later in a commissioning process, the calorimeter’s accuracy was tested using a controllable heat source. A cartridge heater with an adjustable heat output was used to compare to the heat measured by the calorimeter. The results show that the calorimeter has an error of 11% for testing the cartridge heater which approximates equivalent 50W of comparable luminaires. The error decreases with increased cartridge heater wattages. Results for a 114 W energy input show an error of less than 1%.