What is the difference between the OG-100 and OG-300 programs?

ICC-SRCC provides several certification programs for solar thermal products, including OG-100 and OG-300. The OG-100 program provides for certification of solar thermal collectors, and requires compliance with the ICC 901/ICC-SRCC 100 Solar Thermal Collector Standard. OG-100 certification requires a range of laboratory tests to assess the safety, durability and thermal performance of each collector. The OG-300 certification program addresses solar thermal systems and requires compliance with the ICC 900/SRCC 300 Solar Thermal System Standard. For OG-300 certification, the use of an OG-100 certified collector is required. Using information on the other system components, including the tank,pump, heat exchanger, controller, piping and valves, the system is modeled to determine performance. ICC-SRCC staff also reviews the components, system design, and manuals to ensure that they meet the minimum requirements of the standard. Testing of the entire system is not required by the Standard. Testing of individual components may be necessary to provide the information needed for the system model, however SRCC makes every effort to utilize existing, qualified component data.

OG-300 certification addresses the entire system, whereas OG-100 certification only covers one part of that system – the 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 system performance.