Heating, cooling and energy management of cold climate educational built environments using green roofs

Abstract

• Improving the thermal performance of schools by proposing a green roof model associated with atriums to manage energy resources and utilize renewable sources • Reducing heat losses from roofs and walls of schools by using green roof and utilizing an atrium system connected to the green roof, particularly against uncontrolled walls of classrooms, provided that atrium windows are present in the winter season • Assisting in natural ventilation improvement through the creation of green roofs associated with atriums, with open atrium windows in the indoor space of classrooms • Utilizing extensive green roofs associated with atriums as educational support spaces in the design of educational units throughout all seasons Educational spaces in the world with a student population of about 600 million people are significant energy consumers. Also, 66 percent of schools are among energy consumers in the lower categories of energy consumption management. Meanwhile, the world's student population is expanding while non-renewable energy sources are running out. Recent investigations highlight schools’ focus on energy efficiency in construction, which is driven by escalating energy expenses and depleting resources. This study presents a model of green schools featuring green roof coverings interconnected with controllable window atriums, leveraging green architecture as a renewable energy solution. It assesses the impact of green roofs coupled with atriums on summer ventilation and winter heat control in cold climate regions, contrasting with conventional school designs. This study aims to improve the thermal performance of schools, reduce heat losses from the roof and walls of schools, and also help improve natural ventilation in classrooms. The research followed a descriptive-analytical approach and employed simulation techniques. The model is simulated using the Carrier HAP, and its analyses are validated by the U.S. Green Building Council's LEED certification. Then, a comparison is made between the thermal loads of the proposed model and the thermal loads of the conventional school model in this climate. The results demonstrate the advantage of using green roofs in improving thermal loads in winter and cooling loads in summer in classroom models with green roofs connected to atriums compared to classrooms with conventional 40 cm thick roofs or 66 cm thick roofs without greenery. Energy savings are achieved by creating schools with green roofs associated with atriums while maintaining students' connection with nature and utilizing this cover as an auxiliary learning space. Energy savings are 54.95% in winter and 76.11% in summer compared to conventional 40 cm thick roofs and 66 cm thick roofs without greenery.