A simplified energy performance assessment method for existing buildings based on energy bill disaggregation

This paper presents a simplified energy performance assessment method for existing buildings in cooling season, which is based on energy bill disaggregation and energy performance analysis. This method requests very limited building energy data and can effectively assess the energy performance at building and system levels, and disaggregate the whole-building consumption into consumptions of three groups of end-uses. This method is based on two basic energy balance principles, i.e., the electricity consumption balances at building level and the cooling energy balances between demand side and supply side of HVAC systems. An optimization algorithm is developed to establish best possible cooling energy balances by minimizing the balance residuals and therefore to disaggregate the energy consumption of different users. The performance of the proposed method was validated in two existing buildings in Hong Kong and Beijing. The results, including the disaggregated energy consumptions and the key energy performance indicators of HVAC system, agreed well with the “measured” data in mechanical cooling months.

► A simplified multi-level energy performance assessment method for existing buildings.
► The method is based on electricity balance and cooling energy balance principles.
► An optimization algorithm is used to minimize cooling balance residuals.
► It disaggregates the electricity consumption of end-users based on electricity bills.
► It requires very limited data while providing results with acceptable accuracy.