A Model of a Near-Zero Energy Home (NZEH) Using Passive Design Strategies and PV Technology in Hot Climates

Recent development has seen a drastic increase in energy use trends in Saudi Arabian buildings leading to a demand for an effective course of action for energy conservation and production. A case study-based research initiative exploring near-zero energy potential in Saudi Arabia was undertaken. A 4-bedroom detached single-family faculty residence at King Fahd University of Petroleum and Minerals (KFUPM) representing common regional housing design trends was utilized. A base case simulation model of the house was developed and validated using short_term and real-time energy consumption data. Three sets of strategies: passive design strategies, representative codes and standards, and renewable technology were employed in the new design of the house. Passive strategies comprised a green roof, a ventilated wall system, a sloped roof, and insulation for thermal bridges. These alternatives helped reduce the annual energy consumption of the house by 17.2%. The most recent version of the International Energy Conservation Code (IECC 2012) was also incorporated along with ASHRAE Standard 62.2 for ventilation. The code and standard together reduced the annual energy consumption by 31.1%. Solar PV was then utilized to reduce grid utilization for the remainder of the house energy loads. This strategy provided 24.7% of the total energy consumed annually. A combination of strategies showed a 70.7% energy consumption reduction, thereby decreasing the energy index of the house from 162.9 to 47.7 kWh/m²/yr. The Zero Energy Building (ZEB) concepts and strategies utilized in this study demonstrate a socially responsible approach to achieving near-zero energy performance for an existing house.