随着政策制定者、建筑商、公用事业公司和最终用户寻求减少我们家庭的温室气体（GHG）影响，解决通常最重要的负荷、空间供暖和家用热水（DHW）设备安装效率低的问题至关重要。这一点在每年供暖日数超过5000华氏度的寒冷气候地区尤为明显，比如芝加哥，那里的住宅楼排放的温室气体占该市温室气体排放量的28%，是所有单一类别中最大的。然而，加州气候温和，但燃气供暖设备的比例非常大，加州所有家庭40%的温室气体排放来自燃气供暖和DHW设备。因此，为了让个人房主和政府达到温室气体减排目标，必须以成本效益的方式解决这些设备的低效问题。如前一篇论文所述，作者概述了开发和演示由高效燃气驱动的住宅空间和水加热系统（“combi”系统）的努力- 燃烧式吸收式热泵（GAHP），目标是将家庭能源和排放影响降低45%或更高（取决于现有设备）。该组合系统的核心是一个低成本的GAHP，使用直接燃烧的单效吸收式热泵，使用氨水工作对。之前对该组件进行的实验室测试表明，该组件具有高性能，在47°F（8.3°C）下的运行效率（AFUE，预计）为140%，标称输出为80 kBtu/hr（23.5 kW），能够对负载进行4:1调制。在之前的实验室测试和单现场试验中，验证了该性能，包括在低于20°F（-6.7°C）的环境温度下持续运行。在本文中，作者概述了在田纳西州和威斯康星州进行的GAHP combi系统初步现场试验的额外发现和经验教训。特别注意该系统的控制，包括平衡DHW优先级和热舒适性，最大限度地提高GAHP运行效率。 作者概述了进一步改进系统设计和控制的机会，以便在保持热舒适的同时最大限度地减少排放，并通过建筑能源模拟对多个气候区域的系统规模进行一般性指导，推断出这些发现。引用:2019年冬季会议，佐治亚州亚特兰大，会议论文

As policymakers, builders, utilities, and end users seek to reduce the greenhouse gas (GHG) impact of our homes, it is critical to address the low installed efficiency of equipment serving what is often the most significant load, space heating and domestic hot water (DHW). This is apparent for cold climate regions with greater than 5,000 heating degree days per year, such as in Chicago where residential buildings are responsible for 28% of the city’s GHG emissions, the largest of any single category. However, this is also true in California with a mild climate but a disproportionately large fraction of gas-fired heating equipment, where 40% of GHG emissions from all CA homes are from gas-fired heating and DHW equipment. Thus, in order for individual homeowners and governments to meet GHG emission reduction targets, it is essential to address the inefficiencies of these equipment cost-effectively. As described in a previous paper, the authors outlined an effort to develop and demonstrate a residential combined space and water heating system ("combi" system) driven by an efficient gas-fired absorption heat pump (GAHP), with the goal of reducing a home’s energy and emissions impact by 45% or greater (depending on existing equipment). At the core of this combi system is a low-cost GAHP, using a direct-fired single-effect absorption heat pump, using the ammonia-water working pair. Prior laboratory testing of this component show high-performance, with an operating efficiency (AFUE, projected) of 140% at 47°F (8.3°C) and with a nominal output of 80 kBtu/hr (23.5 kW), capable of 4:1 modulation for load following. In prior laboratory testing and a single-site field trial, this performance was verified, including sustained operation at ambient temperatures below 20°F (-6.7°C). In this paper, the authors outline additional findings and lessons learned from these preliminary field trials of the GAHP combi system, at sites in Tennessee and Wisconsin. Specific attention is paid to the controls of this system, including balancing DHW priority with thermal comfort, maximizing GAHP runtime for operational efficiency. The authors outline the opportunity for further improvements to system design and controls, to maximize emissions reductions while maintaining thermal comfort, and extrapolate these findings with general guidance on system sizing across multiple climate regions with building energy simulation.