Wu Wei, Skye Harrison M
National Institute of Standards and Technology, Engineering Laboratory, Energy and Environment Division, HVAC&R Equipment Performance Group, USA.
School of Energy and Environment, City University of Hong Kong, Hong Kong, China.
Energy Convers Manag. 2018;177. doi: 10.1016/j.enconman.2018.09.084.
This study compared the energy performance and initial cost of photovoltaic (PV) and heating, ventilating, and air-conditioning (HVAC) equipment for a residential net-zero energy building (NZEB) in different climate zones across the United States. We used an experimentally validated building simulation model to evaluate various electrically-powered and commercially-available HVAC technologies. The HVAC accounted for 23.8 % to 72.9 % of the total building energy depending on the HVAC option and climate zone. Each HVAC configuration was paired with a PV system sized to exactly reach the net-zero energy target, so the economics were compared based on the initial PV + HVAC cost. Mechanical ventilation was considered with and without heat recovery; the heat recovery ventilator (HRV) saved a significant amount of energy in cold winter months and hot summer months, and the energy recovery ventilator (ERV) provided additional benefit for humid zones. The HRV was cost-effective in the cold northern latitudes of Chicago, Minneapolis, Helena, and Duluth, where energy savings reached 17.3 % to 19.7 %. In other climates, ventilation without recovery was more cost effective, by 1 % to 9 %, and sometimes even more energy efficient. The ERV was never the lowest cost option. A ground-source heat pump (GSHP) and an air-source heat pump (ASHP) were compared, with the GSHP providing significant energy savings, 24.3 % to 39.2 %, in heating-dominated climates (Chicago through Duluth). In warmer climates, the GSHP saved little energy or used more energy than the ASHP. The PV + HVAC cost was lower everywhere with the ASHP, though it is possible for colder climates that a carefully sized GSHP and ground loop could be cost-competitive. The energy and cost data as well as the required PV capacity could guide HVAC and PV designs for residential NZEBs in different climate zones.
本研究比较了美国不同气候区住宅净零能耗建筑（NZEB）中光伏（PV）设备与供暖、通风和空调（HVAC）设备的能源性能及初始成本。我们使用经过实验验证的建筑模拟模型来评估各种电动且市售的HVAC技术。根据HVAC选项和气候区的不同，HVAC能耗占建筑总能耗的23.8%至72.9%。每种HVAC配置都与一个大小恰好能达到净零能耗目标的光伏系统配对，因此基于光伏+HVAC的初始成本来比较经济性。考虑了有无热回收的机械通风；热回收通风机（HRV）在寒冷的冬季和炎热的夏季节省了大量能源，而能量回收通风机（ERV）在潮湿地区提供了额外益处。HRV在芝加哥、明尼阿波利斯、海伦娜和德卢斯等寒冷的北纬地区具有成本效益，节能率达17.3%至19.7%。在其他气候条件下，无回收的通风在成本效益上更高，高出1%至9%，有时甚至更节能。ERV从来都不是成本最低的选项。比较了地源热泵（GSHP）和空气源热泵（ASHP），在以供暖为主的气候区（从芝加哥到德卢斯），GSHP节能显著，达24.3%至39.2%。在较温暖的气候区，GSHP节能很少或比ASHP消耗更多能源。使用ASHP时，各地的光伏+HVAC成本都更低，不过在较寒冷的气候区，精心设计尺寸的GSHP和地环路有可能在成本上具有竞争力。能源和成本数据以及所需的光伏容量可为不同气候区的住宅NZEB的HVAC和光伏设计提供指导。
