A computer system with a software was designed to obtain air temperatures, velocities and solar radiation data in the classroom. Seven temperature readings were recorded. The graph in Figure 13, shows temperature readings for inside the classroom and air entering — existing the collector. The top vent air (air existing) temperature of the collector on the increase when the sun shines. The difference between the top vent and bottom vent air temperatures is maximum at peak solar collection time on the south (between 12.00-15.00). On clear days the temperature difference is about 25-28 °С. Moreover, air temperature existing the collector is about 25-27 °С higher than the inside temperature of the classroom. As seen in Figure 14 , The top vent air velocity is about 0.5-0.6 m/sn at the same hours.

Figure 13. The temperature readings for inside of the classroom and air entering-existing the collector. (21-22

March 2005)

2. Conclusion

In conclusion, the insulated backing of the solar collector serves the dual function of blocking heat transfer between the classroom and the back of the profiles (and air chambers) and insulating the window area to reduce heat transfer from the classroom to the outdoors. This system provides heat by convection during sunny hours and also reduces heat loss on overcast days. This suggested system has the advantage of not requiring any modification to the existing heating system or of occupying any interior space. The solar energy collector is easy to both install and remove as required.

References

[1] G. Z. Gedik, A. Koyun, T. Yilmaz, (2004). Utilization Of Solar Energy Systems For Retrofit Design Of School Buildings And An Example Application, A research project, The Scientific And Technical Research Council Of Turkiye (TUBITAK), Project No: IQTAG-I241.

[2] G. Z. Gedik, (2002). Utilization of solar energy systems for school buildings, (in Turkish), Symposium on clean energy, Vol 1, pp. 259-266, Istanbul.

[3] M. Meltzer, (1985). Passive Active Solar Heating Technology, New Jersey, Prentice Hall Inc.

[4] G. Z. Gedik, A. Koyun, T. Yilmaz, “Utilization of Solar Energy Systems for Retrofit Design of School Buildings and an Example Application” 4th European Conference on Energy Performance and Indoor Climate and 27th Conference of the Air Infiltration and Ventilation Centre (EPIC 2006 AIVC), Lyon, Vol.1, 115-120, 20-22 November 2006.

[5] G. Z. Gedik, A. Koyun, T. Yilmaz, “ An Experimental and Numerical Analyze of a Solar Collector”

3rd International Symposium On Environment, 22-25 May 2008, Athens, Greece