Energy performance enhancement in multistory residential buildings

This paper presents a study of energy performance enhancement methods in multistory residential buildings. The study is carried out for Montreal location, Canada (45°N). All configurations considered assume a suburban environment that allows high solar exposure and no obstruction from adjacent buildings or external surrounding objects such as trees. Energy performance is measured by the balance between energy consumption, on the demand side, and electricity production by means of integrated PV systems, on the supply side. The present study considers enhancement of the supply side by increasing electricity generation potential.Apartment buildings are designed to be highly energy efficient and to conform to passive solar design principles. The buildings investigated include – low rise (3–5 floors), mid-rise (6–9 floors) and high-rise (up to 12 floors), with eight apartments per floor. All Integration of PV systems in façades, in addition to roof surfaces, is considered, in view of the reduced availability of roof surface per dwelling unit. The results of simulations employing the EnergyPlus building simulation program indicate that apartment buildings are relatively energy efficient for heating and cooling, while allowing a high level of residential density, but their solar potential is limited. Under the present study, a building of three stories can generate about 96% of its total energy use, if the roof design is optimized for solar energy generation. Above 3 floors, additional measures are required to enhance energy production. Implementing PV systems on 50% of south façade and 80% of east and west façades surface areas, in addition to enhanced roof surface design (folded-plate), enables electricity production of up to 90% of energy use of a 4-story building reducing with increasing height to 50% for 12 stories.The study indicates that investment in advanced design of façades (such as folded-plate curtain walls) can substantially increase electricity production and achieve net zero and surplus energy status in building over eight stories high.