An evaluation of solar domestic hot water control systems

Journal Article · Tue May 01 04:00:00 EDT 1984 · J. Sol. Energy Eng.; (United States)

DOI:https://doi.org/10.1115/1.3267587· OSTI ID:6240482

Farrington, R

Literature on solar domestic hot water (SDHW) control systems was reviewed to assess results of control system performance and reliability. Seven SDHW control systems underwent six laboratory tests: a sensor temperature response characterization, a sensor stagnation test, a controller function test, a controller vibration test, a controller environmental exposure test, and a controller inspection and high-potential test. Both the literature review and the testing indicate serious concerns with SDHW control system performance and reliability. The results of the laboratory tests included failure of 9 of 15 thermistors due to stagnation conditions, drifting of sensor response, differentials strongly dependent on the system temperature, electronic failure caused by high ambient temperatures and humidity, and the failure of the equipment to meet published specifications. Because of these problems, a control system could operate the pump when the storage tank is warmer than the collector. Because control systems for SDHW systems and active space heating systems are similar, many of the results presented here can be extrapolated to apply to active space heating control systems as well.

• Research Organization: Solar Energy Research Inst., Golden, CO
• OSTI ID: 6240482
• Journal Information: J. Sol. Energy Eng.; (United States), Journal Name: J. Sol. Energy Eng.; (United States) Vol. 106:2; ISSN JSEED
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140907* -- Solar Thermal Utilization-- Water Heating
APPLIANCES
CONTROL SYSTEMS
EQUIPMENT
FAILURES
FUNCTIONS
HEATERS
PERFORMANCE
PERFORMANCE TESTING
RELIABILITY
RESPONSE FUNCTIONS
SOLAR EQUIPMENT
SOLAR WATER HEATERS
SYSTEM FAILURE ANALYSIS
SYSTEMS ANALYSIS
TESTING
WATER HEATERS