Paper Conference

Proceedings of eSim 2020: 11th Conference of IBPSA-Canada


Influence of early stage design variables and thermal mass on energy flexibility in net-zero energy buildings

Samson Yip, Andreas K. Athienitis, Bruno Lee
Concordia University, Canada

Abstract: Demand side energy flexibility measures based on demand response can assist in grid stability by minimizing energy demand and generation mismatches in net zero energy buildings (NZEBs) due to onsite renewables’ generation. Thermal mass has been found to be beneficial in such energy flexibility measures, but its relationship to architectural design variables typically considered at the early design stage has not been examined. Therefore in this paper, an NZEB with a building-integrated photovoltaic/thermal (BIPV/T) roof system was considered. Different plan shapes and orientations were analysed with variable building thermal mass and a heat pump through an automated simulation workflow for their impact on flexibility over the critical Canadian winter period. A flexibility strategy of temperature setpoint ramps was used for peak load and energy consumption reduction targeting the morning and afternoon peak periods. The generated designs were compared by their flexibility potential. When using the flexibility scenario, results show that thermal mass on the floor is the most influential variable for peak load among the ones examined, with the thermal mass on the wall second. The different plan shape and orientation configurations using the flexibility strategy and thermal mass were able to reduce morning and evening peak power by up to 16.98% and 21.67%, respectively, and reduce total electricity imported during the same peak periods by up to 3.10% and 20.68%, respectively. The results demonstrate that through a design approach integrating passive and active components, thermal mass and energy flexibility measures, there are different building form pathways to net-zero energy while providing energy flexibility potential.