Seasonal analysis comparison of three air-cooling systems in terms of thermal comfort, air quality and energy consumption for school buildings in Mediterranean climates

Efficient air-cooling systems for hot climatic conditions, such as Southern Europe, are required in the context of nearly Zero Energy Buildings, nZEB. Innovative air-cooling systems such as regenerative indirect evaporative coolers, RIEC and desiccant regenerative indirect evaporative coolers, DRIEC, can be considered an interesting alternative to direct expansion air-cooling systems, DX. The main aim of the present work was to evaluate the seasonal performance of three air-cooling systems in terms of air quality, thermal comfort and energy consumption in a standard classroom. Several annual energy simulations were carried out to evaluate these indexes for four different climate zones in the Mediterranean area. The simulations were carried out with empirically validated models. The results showed that DRIEC and DX improved by 29.8% and 14.6% over RIEC regarding thermal comfort, for the warmest climatic conditions, Lampedusa and Seville. However, DX showed an energy consumption three and four times higher than DRIEC for these climatic conditions, respectively. RIEC provided the highest percentage of hours with favorable indoor air quality for all climate zones, between 46.3% and 67.5%. Therefore, the air-cooling systems DRIEC and RIEC have a significant potential to reduce energy consumption, achieving the user’s thermal comfort and improving indoor air quality.针对南欧等炎热气候场景下的高效风冷系统，在近零能耗建筑（nearly Zero Energy Buildings, nZEB）的发展背景中有着明确的应用需求。诸如蓄热式间接蒸发冷却器（regenerative indirect evaporative coolers, RIEC）、除湿型蓄热式间接蒸发冷却器（desiccant regenerative indirect evaporative coolers, DRIEC）在内的创新风冷系统，可作为直接膨胀式风冷系统（direct expansion air-cooling systems, DX）的极具竞争力的替代方案。本研究的核心目标为：在标准教室场景下，从空气质量、热舒适表现与能耗三个维度，评估三款风冷系统的季节性能。研究针对地中海区域的四种不同气候分区，开展多组全年能耗模拟以计算上述三项评价指标，所有模拟均采用经经验验证的模型。结果表明，在最热的两类气候条件（兰佩杜萨与塞维利亚）下，DRIEC与DX的热舒适表现分别较RIEC提升29.8%与14.6%；但在此类炎热气候条件下，DX的能耗分别较DRIEC高出3倍与4倍。RIEC可实现所有气候分区中最高比例的优良室内空气质量时段，占比区间为46.3%至67.5%。综上，DRIEC与RIEC两款风冷系统在降低能耗、满足使用者热舒适需求及改善室内空气质量方面，均具备显著的应用潜力。