SIMPLIFIED METHODOLOGY FOR EVALUATION THE ENERGY EFFICIENCY OF LED LUMINAIRES

Measuring the real heat output from electrical equipment is a delicate problem because the heat transfer is a non-linear process. In order to estimate the total heat released by LED luminaires, in this paper is presented a simplified methodology that involves both measurements and calculus. For a higher calculation efficiency, is proposed an Excel application based on the formulas presented in this study. It was used a quasi-adiabatic sealed box, made of high density expanded polystyrene with a 10 cm thickness. The measurements (air temperature, air relative humidity) were made in nine measuring points located on the interior walls of the adiabatic box while a LED lamp was functioning inside it one at a time. It was also measured the medium temperature on the adiabatic box surface. For each of the three analyzed luminaires, the measurement results for each spot inside the adiabatic box were the input data for the Excel application. The results presented in this paper are very close to those provided by the luminaire manufacturers. About 20% of the electrical power is actually transformed into light by a LED luminaire and the rest is released in the environment as heat.