为了预测建筑环境系统的能源需求，必须对该系统进行模拟。在大多数情况下，系统是通过计算机程序模拟的；该模拟的输入是建筑物内不同区域或空间的瞬时热负荷和冷负荷信息。输出是对当时系统的燃料或能量需求的计算。可能有几百种不同的能源项目在运行，从需要大型计算机的广泛项目到用于机械系统初步筛选的精简项目，复杂程度各不相同。 我们相信，复杂和精简的项目都有自己的位置；但是，无论大小，计算机程序的复杂程度应该是一致的。例如，如果将本节的输出输入到粗略的系统模拟中，则不适合进行非常精细的负荷计算，这需要对建筑属性进行详细的输入和精确的定义，并消耗大量的计算机时间。如果程序开发人员接受统一复杂度的概念，他仍然面临着通过采取某些捷径在系统模拟中引入的误差大小的问题。 建筑供暖和制冷能源需求小组ASHRAE任务已经开发出模拟系统的初步程序。1任务组提出了尽可能精确的程序，但也承担了建议如何以最小的精度牺牲简化系统模拟程序的责任。在能源任务组的监督下，ASHRAE赞助了一项研究拨款RP-131，主要用于支付进行本文所述研究所需的计算机时间。该项目名为“能源计算模拟系统程序的初步敏感性研究”，详细内容见参考文献。 2和3。本文总结了调查的结论。引用:肯塔基州路易斯维尔ASHRAE Transactions第79卷第2部分

To predict the energy requirements of a building environmental system, a simulation of the system must be performed. In most cases, the system is simulated by means of a computer program; the input to this simulation is information of the momentary heating and cooling loads from various zones or spaces within the building. The output is the calculation of fuel or energy requirements of the system at that time.There are probably several hundred different energy programs in operation, varying in sophistication from extensive ones requiring large computers to streamlined ones that serve for the initial screening of mechanical systems. We believe that both the sophisticated and the streamlined programs have their place; but regardless of its size the level of sophistication of the computer program should be uniform throughout. For example, it is inappropriate tomake a very refined load calculation entailing elaborate input and precise definition of building properties and consuming large amounts of computer time, if the output of this section is fed to a crude system simulation. If the program developer accepts the concept of uniform sophistication, he is still faced with the question of the magnitude of errors introduced in the system simulation by taking certain shortcuts.The ASHRAE Task, Group on Energy Requirements for Heating and Cooling of Buildings has developed preliminary procedures for simulating systems.1 The Task Group has proposed procedures that are as accurate as our present knowledge permits, but has also assumed the responsibility of suggesting how to simplify system simulation procedures with a minimum sacrifice in accuracy. Under the supervision of the Energy Task Group, ASHRAE has sponsored a research grant, RP-131, that primarily covers the cost of computer time to conduct the study reported in this paper. The project is titled, Preliminary Sensitivity Study of Procedures for Simulating Systems for Energy Calculations, and the details are presented in Refs. 2 and 3. This paper summarizes the investigation's conclusions.