根据适用于家用罐式热水器（Z21.10.1和Z21.10.3）和锅炉（Z21.13）的ANSI Z21标准中规定的安全测试协议，在“海平面”、5400英尺（1646米）和10000英尺（3048米）的标称海拔处对三台不同的热水器和三台不同的锅炉进行了测试。试验计划的目的是设计一种方法，通过这种方法，在“海平面”上进行试验可以预测高空的结果，如果不可能，则确定可用于确定在高空的适当/安全性能的试验程序。该计划的一个子集是确定CAN1-2.17测试程序的适当性，以“预测”并列出4500英尺（1372米）的正确操作。该计划的第二个子集是确定通过自然减额或4%减额规则减少输入是否会改变产品排气类别（第一类、第二类、第三类或第四类）的分类。 该计划的第三个子集是快速审查通风管道（进气和排气）模拟器可用于消除设置数百英尺通风管和进气管的繁琐任务的可能性，以便在水平通风、风扇辅助燃烧产品上进行海拔测试。本报告应有益于燃气设备和控制制造商、燃气公用事业公司、燃气设备测试/上市机构以及负责北美高海拔地区燃气设备正确操作和安装的规范官员。在撰写本论文时，我们试图适应各种燃气设备专业知识，从经验丰富的燃气设备工程师到燃气设备业务新手，无论是否有工程背景。

Three uniquely different water heaters and three uniquely different boilers were tested at nominal elevations of "sea level", 5,400' (1646 m) and 10,000' (3048 m) in accordance with the safety test protocols laid out in the appropriate ANSI Z21 standards for domestic tank type water heaters (Z21.10.1 and Z21.10.3) and boilers (Z21.13).The objective of the test program was to either devise a method by which testing at "sea level" could predict the results at high altitude, and if that was not possible, identify test procedures that might be utilized to ascertain proper/safe performance at elevation. One subset of the program was to ascertain the appropriateness of the CAN1-2.17 test procedures for "predicting" and listing proper operation to 4,500' (1372 m). A second subset of the program was to determine if the reduction in input by natural derate or by the 4% derate rule would alter the classification of the venting Category of the product (Cat I, II, III or IV). A third subset of the program was to quickly review the possibility that vent piping (intake and exhaust) simulators could be used to eliminate the tedious task of setting up hundreds of feet of vent and air intake pipe in order to run testing at elevation on horizontally vented, fan assisted combustion products. This report should be beneficial to gas appliance and control manufacturers, gas utilities, appliance testing/listing agencies and code officials responsible for the proper operation and installation of gas appliances in high elevation areas of North America.An attempt has been made in the writing of this paper to accommodate all levels of gas appliance expertise, from the experienced gas appliance engineer to persons new to the gas appliance business and with or without benefit of an engineering background.