Assembly and comparison of available solar hot water system reliability databases and information.

Technical Report · Fri May 01 04:00:00 EDT 2009

DOI:https://doi.org/10.2172/956867· OSTI ID:956867

Menicucci, David F ^[1]

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1. Building Specialists, Inc., Albuquerque, NM

Solar hot water (SHW) systems have been installed commercially for over 30 years, yet few quantitative details are known about their reliability. This report describes a comprehensive analysis of all of the known major previous research and data regarding the reliability of SHW systems and components. Some important conclusions emerged. First, based on a detailed inspection of ten-year-old systems in Florida, about half of active systems can be expected to fail within a ten-year period. Second, valves were identified as the probable cause of a majority of active SHW failures. Third, passive integral and thermosiphon SHW systems have much lower failure rates than active ones, probably due to their simple design that employs few mechanical parts. Fourth, it is probable that the existing data about reliability do not reveal the full extent of fielded system failures because most of the data were based on trouble calls. Often an SHW system owner is not aware of a failure because the backup system silently continues to produce hot water. Thus, a repair event may not be generated in a timely manner, if at all. This final report for the project provides all of the pertinent details about this study, including the source of the data, the techniques to assure their quality before analysis, the organization of the data into perhaps the most comprehensive reliability database in existence, a detailed statistical analysis, and a list of recommendations for additional critical work. Important recommendations include the inclusion of an alarm on SHW systems to identify a failed system, the need for a scientifically designed study to collect high-quality reliability data that will lead to design improvements and lower costs, and accelerated testing of components that are identified as highly problematic.

• Research Organization: Sandia National Laboratories
• Sponsoring Organization: USDOE
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 956867
• Report Number(s): SAND2009-2757
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
DESIGN
FLORIDA
HOT WATER
RECOMMENDATIONS
RELIABILITY
REPAIR
SOLAR HEAT ENGINES
SOLAR POWER PLANTS
SOLAR THERMAL CONVERSION
SOLAR THERMAL POWER PLANTS
Solar collectors-Design and construction.
Solar energy.
Solar water heaters-Handbooks
manuals
etc.
TESTING
VALVES