Influence of Fresh Air Change Rate on Energy Consumption of Office Buildings

Abstract

This study provides a technical method for office building HVAC systems in hot-summer and cold-winter regions to use fresh air to bear part of the cooling load during transition seasons. The control algorithm for HVAC energy consumption based on the change of outdoor dry-bulb temperature with different ventilation times is also provided, which can reasonably utilize outdoor air to bear indoor cooling load and improve indoor air quality, significantly saving building energy consumption. For typical seasons, that is, early April to the end of May and early August to the middle of November, the energy savings vary with the change of ventilation times. This method cannot be used in summer and winter. The typical days in spring and autumn show that the more the ventilation times, the more the energy saving. Based on the experimental results, the function of the indoor HVAC power consumption changing with the ventilation times and outdoor temperature was fitted in the range of [-2, 37] °C, and this function can guide the setting of building operating conditions within the temperature range of [-2, 30] °C. According to the above changes, under the precise control for typical hot-summer and cold-winter cities, the simulation shows that this method can save 15.57% of the overall building energy consumption compared with normal HVAC operation.