关于热水器“第一小时额定值”的含义以及应该如何应用，人们存在相当大的困惑。介绍美国能源部规定的各种“第一小时额定值”测试和额定值程序，然后检查这些额定值与热水器实际现场性能的关系。来自16个全仪表电热水器现场测试现场的大量现场测试数据表明，大部分热水流出是由于在相对较短的时间内施加的高流速、高流量消耗。此外，相对较少的二次跳动发生在初始跳动之后，而那些确实发生的二次跳动通常发生在初始跳动之后不久。在这些最频繁发生的跳动情况下，热水器是否能够满足负荷的主要决定因素是最大值- 抽油能力（即与油箱容积直接相关）。过去或目前提出的各种首小时额定值，在预测要使用的正确水箱尺寸时，没有一个是一贯有用的，因为在最常导致热水流失的短时、大容量的抽水情况下，能量消耗率如此之高，以至于没有常用的水箱式热水器（化石或电力）能够足够快地加热水以防止热水流失。虽然现场试验数据表明，水箱容积（更准确地说，是最大首次抽汽能力）是热水系统充分性的最强决定因素，但它也表明再热率并非不重要。再热率仍然是一个重要因素，但与储罐容积相比，其重要性居第二位。关键词:1996年，热水器，额定值，测试，比较，热水供应，尺寸，水箱，热水，美国引文: 研讨会论文，乔治亚州亚特兰大，1996年

There is considerable confusion about just what water heater "first-hour rating" means and how it should be applied. Describes the various "first-hour rating" testing and rating procedures set forth by the US Department of Energy and then examines how those ratings relate to actual in-field performance of water heaters. Extensive field test data from 16 fully instrumented electric water heater field test sites reveal that the majority of hot-water runouts are due to high-flow-rate, high-volume draws imposed over relatively short times. Moreover, relatively few secondary runouts occur after the initial runout, and those that do occur usually are soon after the initial runout. Under these most frequently occurring runout conditions, the major determinant of adequacy of a water heater to serve the load is maximum first-draw capability (i.e., directly related to tank volume). None of the various first-hour ratings, past or currently proposed, is consistently useful for predicting the correct tank size to be used because under the short-duration, high-volume draws that most frequently cause hot water runouts, the energy withdrawal rates are so high that no commonly used tank-type water heaters (fossil or electric) heat the water fast enough to prevent the runout. While the field test data show that tank volume (more correctly, maximum first draw capability) is the strongest determining factor of adequacy of a water-heating system, it also shows that reheat rate is not unimportant. Reheat rate is still an important factor, but is of secondary importance compared to tank volume.KEYWORDS: year 1996, water heaters, rating, testing, comparing, hot water supply, sizing, water tanks, water heating, USA