The Impact of HVAC Setpoint Temperature on Reducing Building Energy Consumption in Different Climatic Regions of Iran

Energy consumption reduction has become increasingly important today, as buildings contribute significantly to energy use. Therefore, strategies to reduce energy consumption in this sector can have a substantial impact on reducing national energy consumption. This research analyzes the energy consumption of a building (a case study of a 492-unit residential complex in Farhangshahr, Ahvaz) and the effect of HVAC setpoint temperature on reducing building energy consumption in four cities with different climates in Iran. To analyze the results, the building design process was simulated using AutoCAD maps in the DesignBuilder software, and EnergyPlus was used for energy calculations. Results show that cooling accounts for 96.1% of energy use in Ahvaz, while heating comprises 84.6% in Tabriz. In Tehran and Yazd, cooling represents 54.6% and 65.5% of total consumption, respectively. Increasing the cooling setpoint from 22°C to 27°C reduces cooling load by 35.7% in Ahvaz and electricity use by 44.6 MWh annually. Lowering the heating setpoint from 21°C to 16°C decreases heating load by 36.4% in Tabriz and gas consumption by 25.8 MWh. These findings emphasize the significant energy savings achievable by optimizing setpoint temperatures based on climate conditions. Additionally, reducing the heating setpoint from 21°C to 16°C results in a 32.6% decrease in annual CO₂ emissions in Ahvaz, with further reductions of 39.6%, 40%, and 40.2% observed in Yazd, Tehran, and Tabriz, respectively.