Energy Efficient Glazing: A Comparison of Microalgae Photobioreactor and Iranian Orosi Window Designs

Orosi is a traditional Iranian window which is made of colorful glasses embedded in wooden latticed frame. This window was designed in traditional courtyard houses located in central Iran and behaved as a passive strategy to control light intensity, provide privacy and aesthetics. However, this type of window is rarely used nowadays due to a lack of acoustic and thermal insulation and high construction costs. This paper explores the possibility of using double-glazed window with colored microalgae inspired by Orosi to improve its light performance and energy consumption compared to the traditional Orosi window design A series of experimental tests and a set of computer simulations are conducted to evaluate and compare the two designs. The experimental results showed that while the light intensity in the indoor space is approximately equal to the corresponding magnitude measured for the Orosi window, the inside temperature witnessed a small increase approximately 1 degrees Celsuis. Likewise, relative humidity, which has a significant impact on thermal comfort perceived by occupants, increased from 25% to nearly 70% in the algae window. Based on results obtained, nearly 500 ppm of CO2 was absorbed due to the low height of the photobioreactor. Results of computer simulations indicated that the amount of annual energy consumption in terms of cooling electric energy, heating fuel energy and electric equipment within the two simulated models were similar. However, the best performance of the colored algae window in terms of UDI was observed when the microalgae concentration was between 40% and 50%.