Thermal Evaluation of an Innovative Type of Unglazed Solar Collector for Air Preheating

Perforated solar walls pre-heat the fresh air introduced in the building when the air is forced to pass through this solar heated perforated facade. The heat transfer between the fluid and the metal is intensified depending especially on the flow's characteristics. An experimental campaign on an innovative solar collector was performed in the laboratory of Building Services from Technical University of Civil Engineering Bucharest. The solar collector with lobed perforations was analyzed and the results indicated that the system can attain a high thermal performance, but only for a certain range of airflow rates.