Ng Lisa C, Dols W Stuart, Emmerich Steven J
Building, Energy and Environment Division, Engineering Laboratory.
Build Environ. 2021 Jun;196. doi: 10.1016/j.buildenv.2021.107783.
According to the U. S. Department of Energy (DOE), infiltration accounts for 6 % of the energy use and $11 billion in energy cost for U. S. commercial buildings. One strategy to reduce infiltration in commercial buildings is to provide more supply airflow than return and exhaust in order to "pressurize the building". DOE has developed EnergyPlus models of several prototype buildings which assume that pressurization results in system-on infiltration rates that are 75 % less than the system-off rates. However, airflow simulations of these buildings using the CONTAM multizone airflow software showed that pressurization reduced infiltration by an average of 44 % only. To improve the infiltration rates calculated by the EnergyPlus models of prototype buildings, CONTAM infiltration rates were used to develop coefficients that can be input into EnergyPlus. CONTAM captures the effects of wind, temperature difference, and system operation on infiltration rates. Coefficients were developed for 11 prototype buildings, eight cities, and two levels of building envelope airtightness. Comparisons of the predicted infiltration rates were made between using the DOE prototype model inputs and the NIST infiltration correlations. Using the NIST correlations resulted in an average HVAC-EUI (HVAC-related energy use intensity) savings of 6 % or 1.4 kBtu/ft due to airtightening. These results indicate that the effects of infiltration on HVAC energy use are important and that infiltration can and should be better accounted for in whole-building energy modeling.
根据美国能源部（DOE）的数据，在美国商业建筑中，渗透占能源使用量的6%，能源成本达110亿美元。减少商业建筑渗透的一种策略是提供比回风与排风更多的送风气流，以便“给建筑物增压”。美国能源部已开发出几种原型建筑的EnergyPlus模型，这些模型假设增压会使系统开启时的渗透速率比系统关闭时低75%。然而，使用CONTAM多区域气流软件对这些建筑进行的气流模拟显示，增压仅使渗透平均降低了44%。为了改进原型建筑的EnergyPlus模型所计算的渗透速率，利用CONTAM渗透速率来开发可输入到EnergyPlus中的系数。CONTAM捕捉了风、温差和系统运行对渗透速率的影响。针对11座原型建筑、8个城市以及两种建筑围护结构气密性等级开发了系数。对使用美国能源部原型模型输入值与美国国家标准与技术研究院（NIST）渗透相关性所预测的渗透速率进行了比较。使用NIST相关性，由于气密性提高，平均暖通空调能耗强度（与暖通空调相关的能源使用强度）节省了6%或1.4英热单位/平方英尺。这些结果表明，渗透对暖通空调能源使用的影响很重要，并且在整栋建筑能源建模中，渗透能够且应该得到更好的考虑。
