Simulation of the Post-Retrofit Thermal Energy Use for the University Teaching Center (UTC) Building with the Use of Simplified System Models

摘要

Several state owned buildings with dual-duct constant volume (DDCV) systems havebeen retrofitted with energy efficient variable air volume systems (VAV) as part of theTexas LoanSTAR Program. One method of determining the energy savings resultingfrom energy conserving retrofits relies on the use of a model for the daily whole buildingconsumption, Epre, in the pre-retrofit configuration. Epre is typically a function of primaryinfluencing parameters such as ambient temperature, humidity, building internal gainsand others (Figure 1). Following the retrofit, the energy saved, Esav is determined usingmeasured daily consumption, Emea3 as shown in Figure 1. This method is being used inthe Texas LoanSTAR monitoring and analysis program for buildings that have adequatepre-retrofit monitored data (Kelly et al., 1992). Unfortunately, in the University Teaching Center (UTC) the retrofits were completedbefore the monitoring instrumentation was installed. Therefore, no pre-retrofit monitoreddata are available. Hence another method to estimate savings was needed. Sucha method was developed and tested on a large engineering center (Katipamula andClaridge 1991). This method was based on the use of the ASHRAE TC 4.7 simplifiedenergy analysis procedure (SEAP). It involved developing one model each for the VAV(post-retrofit system) and the DDCV (pre-retrofit system) systems.