Maintaining optimum light output with a thermally conductive heat pipe

The authors describe current research in using a thermally conductive heat pipe to maintain optimum lamp wall temperature under varied ambient temperatures. The heat pipe has advantages over previous methods of enhancing light output in that no external power is necessary and orientation within the fixture is flexible. 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 through an ambient temperature range that typically reduces light output by 20%.<>