Current solar water heaters still facing some weaknesses in the performance and efficiency loss, such as the dependency of heat transfer rate between the heat pipe and the cold water to temperature difference and flowrate, and stratification effect in the hot water tank, which all affects total deliverable hot water volume to the end-user. Within the past decade, many research activities attacked these issues and provided different types of solutions. One of the solutions is using phase change materials as a thermal energy storage unit or as part of it. This paper compares 21 parameters related to the technical specifications, structural design, economic, and health related issues of four of the full-scale experimental studies of solar water heaters with latent heat thermal energy storage. This study is essential and indicative to facilitate and pave the way for future research and development of such products. All of the reported solar water heater systems with latent heat thermal energy storage unit systems were the primary design, with no optimization study. With the positive improvement in the performance of these units, it could be expected that the new generation of SWH systems will utilize the advantages of the latent heat storage unit, by using PCMs. There is potential for improvement in these systems in the fields related to the optimization of the TES unit, infrastructure, and cost of the system. The impact of weather conditions in different climatic conditions needs more investigation.

当前的太阳能热水器在性能和效率损失上仍然面临一些弱点，例如热管和冷水之间的传热速率对温差和流量的依赖性以及热水箱中的分层效应，这些都会影响总的可交付给最终用户的热水量。在过去的十年中，许多研究活动都对这些问题进行了攻击，并提供了不同类型的解决方案。解决方案之一是使用相变材料作为热能存储单元或其一部分。本文比较了四个具有潜热热能存储的太阳能热水器的全面实验研究中的21个与技术规格，结构设计，经济和健康相关问题有关的参数。这项研究是必不可少的，具有指示意义，有助于为此类产品的未来研究和开发铺平道路。所有报告的带有潜热热能存储单元系统的太阳能热水器系统都是主要设计，尚无优化研究。随着这些单元性能的积极提高，可以预期，新一代的SWH系统将通过使用PCM利用潜热存储单元的优势。这些系统在与TES单元，基础设施和系统成本的优化有关的领域中有可能得到改进。天气条件在不同气候条件下的影响需要更多研究。所有报告的带有潜热热能存储单元系统的太阳能热水器系统都是主要设计，尚无优化研究。随着这些单元性能的积极提高，可以预期，新一代的SWH系统将通过使用PCM利用潜热存储单元的优势。这些系统在与TES单元，基础设施和系统成本的优化有关的领域中有改进的潜力。天气条件在不同气候条件下的影响需要更多研究。所有报告的带有潜热热能存储单元系统的太阳能热水器系统都是主要设计，尚无优化研究。随着这些单元性能的积极提高，可以预期，新一代的SWH系统将通过使用PCM利用潜热存储单元的优势。这些系统在与TES单元，基础设施和系统成本的优化有关的领域中有可能得到改进。天气条件在不同气候条件下的影响需要更多研究。可以预期，新一代的SWH系统将通过使用PCM利用潜热存储单元的优势。这些系统在与TES单元，基础设施和系统成本的优化有关的领域中有可能得到改进。天气条件在不同气候条件下的影响需要更多研究。可以预期，新一代的SWH系统将通过使用PCM利用潜热存储单元的优势。这些系统在与TES单元，基础设施和系统成本的优化有关的领域中有可能得到改进。天气条件在不同气候条件下的影响需要更多研究。