In this paper, a double-glazed solar air heater (SAH) using paraffin wax as phase change material (PCM) was designed, fabricated, and tested under the climatic condition of Mashhad, Iran (latitude, 37 280 N and longitude, 57 200 E) during three typical days in the summer. The PCM stores solar radiation of the sun as latent and sensible heat during daytime and then restores such stored energy during the night. Exploitation of both first and second laws of Thermodynamics, the energy and exergy efficiencies of this system are assessed. According to the experiments undertaken, it is found that the daily energy efficiency of the system varies between 58.33% and 68.77%, whereas the daily exergy efficiency varies from 14.45% to 26.34%. Eventually, the economic analysis shows that the cost of 1 kg of heated air utilizing double-glazed SAH would be 0.0036$.

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