ASHRAE RP-1282 Lighting Heat
Gain Distribution in Buildings
The energy dissipated
by lights is a significant contributor to the space heat gain and the space
cooling load in many commercial buildings. To account for the heat gain due to
lights, both of ASHRAE's new cooling load calculation procedures require two
lighting heat gain parameters, the conditioned space/ceiling plenum split and
the radiative/convective split, as input data. However, existing data are
limited and may be obsolete due to recent advancements in lighting technologies.
The current project addresses the need to provide relevant lighting heat gain
parameters for a range of common luminaires. The primary objective of the study
is therefore to accurately measure these lighting heat gain parameters under
realistic operating conditions in a full-scale experimental room. An additional
objective is to provide the experimental results in a format that can be readily
applied to the ASHRAE cooling load procedures.
Shortwave and longwave radiation
leaving the luminaire towards the room are measured with a net radiometer on a 5
degrees-of-freedom traversing rig. A schematic, photos of the experimental
apparatus, and a few images showing sample results are shown below.
Keywords: cooling load calculation,
lighting, heat gains, radiation, convection
Radiometer Traversing Fixture
Radiative Heat Flux Distributions for Recessed Fluorescent Luminaries