A Laboratory Method for Measuring the Heat Distribution of Luminaires and Its Application for Building Heating and Cooling Energy Saving

Abstract

This study was aimed to explore the energy saving potential of a new system architecture of solid-state lighting fixtures that was designed to help utilize the heat generated by LEDs for spacing heating in heating season and re-heating in cooling season. The new system architecture, which deploys an innovation of integrative light and heat arrangement in low profile, helps harvest the LED heat and direct most of the heat to the room space while minimizing heat leakage to the ceiling cavity. A well-designed laboratory experiment was carried out in a newly developed Calorimeter chamber that was used to find out heat distribution of luminaires in the conditioned room cavity and ceiling plenum, followed by an estimation of potential energy savings via computer simulation in Energy Plus. A typical primary elementary school classroom was used in this computer simulation equipped with LED fixtures with different heat distribution patterns. It was found that in heating season, the building space heating energy consumption could be reduced as the ‘conditioned space/ceiling plenum split’ increased. While in cooling season, the LED heat gain in the conditioned room could be utilized to warm up the chilled supply air to supplement the function of reheating system. The new system architecture of LED fixtures with integrative lighting and heating arrangement could save 4.4%-4.7% of annual building heating and cooling energy uses by reducing reheating energy consumption in cooling season and space heating energy consumption in heating season.