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.
BT - Energies DA - 05/2020 DO - 10.3390/en13092382 IS - 9 LA - eng N2 -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.
PY - 2020 EP - 2382 ST - Energies T2 - Energies TI - Modeling Thermal Interactions between Buildings in an Urban Context UR - https://www.mdpi.com/1996-1073/13/9/2382https://www.mdpi.com/1996-1073/13/9/2382/pdf VL - 13 ER -