Maintaining Optimum Light Output with a Thermally Conductive Heat Pipe

This paper describes some of the current research in the area of lamp wall temperature control for the purpose of enhancing light output under elevated temperatures. More specifically a thermally conductive heat pipe has been employed to maintain optimum lamp wall temperature under varied ambient temperatures. Advantages of a heat pipe over previous methods of enhancing light output include no external power necessary and flexibility in orientation within the fixture. The experiments described include the calibration of a heat pipe against a known thermal load, the application of a heat pipe to a lamp in a test chamber and the placement of a heat pipe within a fixture. Theory and experimental data indicate that optimum lamp operating conditions can be maintained throughout an ambient temperature range which typically reduces light output by 20%.