A smart green mashrabiyya-shutter design for residential applications in Egypt

Figures & data

Figure 1. A mashrabiyya in Zaynab Khatoun House. (drawings and photo by the author).

Figure 2. Design methodology. (the authors).

Figure 3. Date palm midribs. (a) whole leaves, (b) cross-section, (c) slats, (d) common table. (photos by the author).

Figure 4. Manufactured static shutter. (a) from outside, (b) from inside, (c) opened, (d) slats detail. (photos by the author).

Figure 5. Annual temperature and wind velocities in Cairo. Left, average temperatures; right, wind velocities according to no. Of days [30].

Table 1. WBGT levels (^oC) [33].

Ranges	Description
<18	Unlimited
18–23	Be careful for signs of heat stress
23–28	Activity should be avoided for those who are not adapted
28–30	Activity should be limited for everyone except the well-adapted
≥30	All activities must be discontinued

Table 2. Simplified daylight glare probability levels [29].

	imperceptible	perceptible	disturbing	intolerable
DGPs limit	≤.35	.35 < DGPs < .4	0.4 ≤ DGPs < 0.45	≥0.45

Figure 6. Proposed dynamic shutter model. (a) opening angles, (b) section, (c) rotating slats and their main controlling rod. (the authors).

Figure 7. Slats cross-section design based on summer sun altitudes in Cairo. Left, sun altitude at 12:00 noon; right, sun altitude at 3:00 pm. (the authors).

Table 3. Sun altitudes in summer from 12:00 noon to 3:00 pm in Cairo [48].

Month	Sun altitude 12:00 noon	Sun altitude 15:00
May	79°	46°
June	83^o	48°
July	80°	48°
August	71°	44°
September	59°	35^o

Figure 8. Visibility analysis using Ladybug. (a) view through the middle part, (b) openness factor of different slat angles. (the authors).

Figure 9. Control circuit design. Left, circuit components and design; right, laboratory testing of components. (the authors).

Table 4. Circuit components of the automated shutter. (the authors).

Component	Digital temperature and humidity sensor		Light dependent resistor (LDR)	DC fan wind sensor	Hybrid stepping motor (actuator)	Controller
Name	DHT11				SL42STH48-1504A	Arduino Mega
Image

Figure 10. Operating concept of the smart shutter in a room. (the authors).

Figure 11. Simplified description of the automated decisions in day mode and night mode in summer. (the authors).

Figure 12. Proposed automated flowcharts for day and night modes in summer. (the authors).

Figure 13. A preliminary code for the control circuit. (the authors).

Meteoblue. Simulated historical climate & weather data for Cairo [online]. Available from: https://www.meteoblue.com/en/weather/historyclimate/climatemodelled/cairo_egypt_360630

 Google Scholar

Zare S, Hasheminejad N, Shirvan HE, et al. Comparing Universal thermal climate index (UTCI) with selected thermal indices/environmental parameters during 12 months of the year. Weather Clim Extremes. 2018 03 01;19:49–57. doi: 10.1016/j.wace.2018.01.004

 Web of Science ®Google Scholar

Do CT, Chan Y-C. Daylighting performance analysis of a facade combining daylight-redirecting window film and automated roller shade. Build Environ. 2021 03 15;191:107596. doi: 10.1016/j.buildenv.2021.107596

 Web of Science ®Google Scholar

Gaisma. Cairo, Egypt - sun path diagram [online]. Available from: https://www.gaisma.com/en/location/cairo.html

 Google Scholar