本文介绍了住宅规模无水箱燃气热水器的现场和实验室监测。在过去十年中进入市场的新型无水箱燃气热水器有潜力通过取代传统的中央烟道蓄热式热水器设计来减少住宅热水能源的使用。在过去的二十年中，中央烟道的设计显示出了微小的效率提升增量，但效率提升受到一种设计的限制，这种设计在机组不点火期间会导致显著的备用损失。 无水箱热水器通过仅在抽水活动期间加热水，在很大程度上消除了备用损失。尽管无水箱热水器具有效率优势和良好的出口温度控制，但这些热水器的安装成本远高于储水式热水器。此外，由于换热器的热循环，无槽机组的性能也会有所下降。在当前的能量因数测试程序中，这种性能退化没有得到充分的体现，从而导致机组性能评级过高。本研究的目的是评估两台无油箱机组的现场和实验室性能，以更好地了解实际性能。 单位:双引文:ASHRAE交易，第114卷，pt。2、盐湖城2008

This paper describes field and laboratory monitoring of residential scale tankless gas water heaters. The new breed of tankless gas water heaters that have entered the market in the past ten years offer the potential to reduce residential domestic hot water energy use by replacing the conventional center flue storage water heater design. The center flue design has shown small incremental efficiency improvements over the past twenty years, but efficiency improvements are limited by a design that results in significant standby losses during periods when the unit is not firing. Tankless water heaters largely eliminate standby losses by heating water only during draw events. Although tankless units offer efficiency benefits and good outlet temperature control, the installed cost for these units is considerably higher than storage water heaters. In addition, tankless units experience some performance degradation due to heat exchanger thermal cycling. This performance degradation is not adequately captured in the current Energy Factor test procedures resulting in over rating of unit performance. The goal of this study was to evaluate field and laboratory performance of two tankless units to develop a better understanding of real world performance.Units: Dual