ASAE/ASABE S423.1 (R2024)

The purpose of this Standard is to provide a method for testing the thermal efficiency of open-looped solar air heaters which are used exclusively for heating ambient air. The test data should provide a basis for computing technical performance and for comparing efficiency of collectors of different design and/or construction. Examples of use of solar ambient air heaters are preheating of ventilation air, heating make-up air for all types of environmental control systems, and heating of air to dry agricultural products without recirculation.