%0 Journal Article %K Urban Building Energy Model (UBEM) %K Thermal interaction %K Longwave radiation %K View factor %K Ray tracing %A Xuan Luo %A Tianzhen Hong %A Yu-Hang Tang %B Energies %D 2020 %G eng %N 9 %P 2382 %R 10.3390/en13092382 %T Modeling Thermal Interactions between Buildings in an Urban Context %U https://www.mdpi.com/1996-1073/13/9/2382https://www.mdpi.com/1996-1073/13/9/2382/pdf %V 13 %8 05/2020 %! Energies %X

Thermal interactions through longwave radiation exchange between buildings, especially in a dense urban environment, can strongly influence a building's energy use and environmental impact. However, these interactions are either neglected or oversimplified in urban building energy modeling. We developed a new feature in EnergyPlus to explicitly consider this term in the surface heat balance calculations and developed an algorithm to batch calculating the surrounding surfaces' view factors using a ray-tracing technique. We conducted a case study with a district in the Chicago downtown area to evaluate the longwave radiant heat exchange e ects between urban buildings. Results show that the impact of the longwave radiant e ects on annual energy use ranges from 0.1% to 3.3% increase for cooling and 0.3% to 3.6% decrease for heating, varying among individual buildings. At the district level, the total energy demand increases by 1.39% for cooling and decreases 0.45% for heating. We also observe the longwave radiation can increase the exterior surface temperature by up to 10 C for certain exterior surfaces. These findings justify a detailed and accurate way to consider the thermal interactions between buildings in an urban context to inform urban planning and design.