Predicting the performance of radiant technologies in attics: Reducing the discrepancies between attic specific and whole-building energy models

•The potential reasons for the poor performance predictions of radiant technologies in EnergyPlus are identified.•Intermodel comparison between FATM, AtticSIM, ASTM C1340, and EnergyPlus is performed for 8 climate zones.•The implemented solution strategy reduces the discrepancies of ceiling heat gains from 16%−28% to 5%−14%. The use of radiant technology in attics aims to reduce the radiation component of heat transfer between the attic floor and roof decks, gables, and eaves. Recently, it has been shown that EnergyPlus underestimates the savings using radiant technologies in attic spaces. The aim of this study is to understand why EnergyPlus underestimates the performance of radiant technologies and provide a solution strategy that works within the current capabilities of EnergyPlus. The analysis uses three attic energy models as a baseline for comparison for EnergyPlus. Potential reasons for the discrepancies between the attic specific energy models and EnergyPlus are isolated and individually tested. A solution strategy is proposed using the Energy Management System (EMS) capabilities within EnergyPlus. This solution strategy produces similar results to the other attic specific energy models. This paper shows that the current capabilities of EnergyPlus are sufficient to simulate radiant technologies in attics. The methodology showcased in this paper serves as a guide for engineers and researchers who would like to predict the performance radiant technology in attics using the whole building energy software, EnergyPlus.