OG-100 certification covers solar thermal collectors, and requires compliance with the ICC 901/SRCC 100 Solar Thermal Collector Standard. OG-100 certification requires testing in an accredited testing laboratory to assess the safety, durability and thermal performance of each collector.
OG-300 certification addresses solar thermal systems (complete solar water heaters) and requires compliance with the ICC 900/SRCC 300 Solar Thermal System Standard. OG-300 certified systems almost always include at least one OG-100 certified solar collector. The system is modeled using information on each component, including the collectors, tanks, pumps, heat exchangers, controllers, piping and valves. SRCC staff also evaluates the components, system design, and manuals to ensure that they meet the minimum requirements of the standard. In most cases, testing of the entire system is not required by the ICC 900/SRCC 300 Standard. However, testing of individual components may be necessary to provide the information needed for the computer model of the system.
OG-300 certification addresses the entire solar water heating system, whereas OG-100 certification only covers one component – the solar thermal collector. OG-100 does provide collector rating information, which allows specific collectors to be compared. However, OG-100 does not provide all of the information needed to describe the performance of the system. OG-100 does not address the other system components that can have a very significant impact on performance, like tanks, pumps, heat exchangers and controls. For example, a collector with a high OG-100 rating paired with a low-quality or poorly matched controller could achieve a low OG-300 rating. OG-100 alone is simply not an adequate predictor of complete system performance.