Cooling Strategies Based on Indicators of Thermal Storage in Commercial Building Mass

Abstract

Building thermal mass and multi-day regimes of hot weather are important, yet poorly understood, contributors to cooling energy requirements. This paper develops load-shifting sub-cooling and precooling equipment operating strategies to address a specific instance of this phenomenon, in which thermal storage by building mass over weekends exacerbates Monday cooling energy requirements. The study relies on computer simulations of energy use for a large, office building prototype in El Paso, TX using the DOE-2 building energy analysis program. The economic value of the strategies is evaluated with direct reference to utility rate schedules and a crude measure of thermal storage is related to the energy impacts of the strategies. The indicators are based on core zone air temperatures, which are sampled a t night when HVAC systems are not in use. The suggestion is made that the results and proposed strategies could be adapted for use by computerized energy management systems to reduce building energy operating costs.