Interactions between lighting and space conditioning energy use in US commercial buildings

Reductions in lighting energy have secondary effects on cooling and heating energy consumption. In general, lighting energy reductions increase heatin g and decrease cooling requirements of a building. The net change in a buil ding's annual energy requirements, however, is difficult to quantify and de pends on the building characteristics, operating conditions, and climate. T his paper characterizes the effects of lighting/HVAC interactions on the an nual heating/cooling requirements of prototypical US commercial buildings t hrough computer simulations using the DOE-2.1E building energy analysis pro gram, Twelve building types of two vintages and five climates are chosen to represent the US commercial building stock. For each combination of buildi ng type, vintage, and climate, a prototypical building is simulated with va rying lighting power densities, and the resultant changes in heating and co oling loads are recorded. These loads are used together with market informa tion on the saturation of the different HVAC equipment in commercial buildi ngs to determine the changes in energy use and expenditures for heating and cooling. Results are presented by building type for the US as a whole. The refore, the data presented in this paper can be used to assess the secondar y effects of lighting-related federal policies with widespread impacts, suc h as minimum efficiency standards. Generally, in warm climates the interact ions will induce monetary savings and in cold climates the interactions wil l induce monetary penalties. For the commercial building stock in the US, a reduction in lighting energy that is well distributed geographically will induce neither significant savings nor significant penalties from associate d changes in HVAC primary energy and energy expenditures. Published by Else vier Science Ltd. All rights reserved.