与传统的独立设备相比，组合式空间和热水系统在历史上为最终用户和安装承包商提供了许多好处——通常是燃气炉或电热泵与标准燃气或电储水式热水器配对。组合系统通常由燃气饮用水（无水箱热水器）或非饮用水（锅炉）热水系统驱动，其优点包括使用一台“热机”降低设备成本，只需一条排气管/气体管线/冷凝水排水管，从而降低安装成本，有效部署后，可产生一致的高运行效率和降低成本。关于高运行效率，这些“组合式”系统通常具有成本效益，可将生活热水（DHW）生产的运行效率提高到冷凝效率（>90%），而在类似效率水平下，独立DHW系统的经济性往往很难实现。 对于大多数使用天然气供暖的美国家庭，尤其是在太平洋西北部、中西部和东北部较冷的气候条件下，作者通过实验室和现场测试证明了一种燃气热泵驱动的住宅组合系统，提高了组合系统的效率。气体热泵（GHP）部件基于低成本单效吸收循环，通过之前的测试，已经证明了ANSI Z21定义的气候区域IV的预计AFUE的运行效率为140%。10.4. GHP在47°F时的标称输出为80 kBtu/hr，能够进行4:1调制，以便在必要时进行负载跟踪。GHP驱动的combi系统旨在为住宅提供空间和水加热，通过循环空气盘管与强制空气加热分配相结合，并加热DHW的间接储水箱，通过模拟试验表明，GHP驱动的combi系统可同时满足家庭的空间和水热负荷- 在实验室进行测试，并在田纳西州的一处住宅进行为期12个月的现场演示。作者概述了GHP驱动的combi系统的性能，以及负载、操作条件（例如环境温度）和系统控制策略的函数。此外，还探讨了系统设计考虑因素对部件尺寸和控制的影响，如间接储罐尺寸，以及除霜事件期间的系统性能。引文:2018年冬季会议，伊利诺伊州芝加哥，会议论文

Combination space and water heating systems have historically offered end users and installation contractors numerous benefits over conventional, standalone equipment – typically a gas furnace or electric heat pump paired with a standard gas or electric storage water heater. Combination systems, typically driven by a gas-fired potable (tankless water heater) or non-potable (boiler) water heating system, offer benefits including reduced equipment costs with one "thermal engine", reduced installation costs through requiring only one vent/gas line/condensate drain, and when deployed effectively, they can yield consistent high operating efficiency and reduced cost. Concerning high operating efficiency, these "combi" systems often cost-effectively improve the operating efficiency of domestic hot water (DHW) production to a condensing efficiency (>90%), where the economics of a standalone DHW system at a similar efficiency level are often difficult. For the majority of U.S. homes that are heated by natural gas, particularly in colder climates of the Pacific Northwest, Midwest and Northeast, the authors have demonstrated a gas heat pump-driven residential combi system, through laboratory and field testing, a step up in combi system efficiency. The gas heat pump (GHP) component is based on a low-cost single-effect absorption cycle and, through prior testing, has demonstrated an operating efficiency of a projected AFUE of 140% for Climate Region IV as defined by ANSI Z21.10.4. The GHP has a nominal output of 80 kBtu/hr at 47°F and is capable of 4:1 modulation, to load follow when necessary. Developed to provide space and water heating to a residence, integrating with a forced-air heating distribution via a hydronic air coil and heating an indirect storage tank for DHW, the GHP-driven combi system is shown to meet a home’s space and water heating loads simultaneously, through simulated-use testing in a laboratory and through a field demonstration over 12 months at a residence in Tennessee. The authors outline the performance of the GHP-driven combi system as a function of loading, operating conditions (e.g. ambient temperatures), and system control strategies. Additionally, the impact of system design considerations for component sizing and control, such as the indirect storage tank size, and system performance during defrost events are explored.