COOLING GREENHOUSES BY CLOSED SYSTEM OF AIR THROUGH EARTH TUBES

Document Type : Original Article

Authors

1 Ass. Prof., King Faisal U., KSA.

2 Post G. St., King Faisal U., KSA.

3 Prof., King Saud U., KSA.

Abstract

This research aims to study the use of the closed system of air through earth tubes for cooling greenhouses. This had been achieved by a field study using plastic earth tubes under the dry and hot climatic conditions of the region under study. An elliptical or semi-circular shaped greenhouse and its accessories were constructed according to the appropriate engineering specifications of the experiment site. Results showed that the closed systems of air through plastic earth tubes can not be used independently for cooling the greenhouse in order to attain the suitable temperature for plant growth but can be used in reducing energy consumption. The performance of the cooling system was capable to reduce temperatures during winter season from 79.4°C-68.6°C i.e. by a magnitude of 10.8°C. Also the system can be used independently during autumn and spring seasons in case of temperate conditions. The study recommends the development of the greenhouse design by burying the earth tubes beneath the house in order to utilize the space, reduce the numbers of tubes and heat loss.

Main Subjects


إبراهیم الهلال ،عبد الرحمن البراهیم, نایف العبادی, (2003). مشروع استغلال أنظمة الخلایا الکهروضوئیة فی تشغیل البیوت المحمیة الزراعیة - ملخصات الأبحاث العلمیة لبرنامج البحث والتطویر المشترک بین مدینه الملک عبد العزیز للعلوم والتقنیة و مرکز الطاقة البترولی الیابانی (ص 83 – 87).
Albright L. D. (1990). Environment Control for Animals and Plants. The American Society of Agricultural Engineers. St. Joseph, MI.
Al-Ajmi F, D. L. Lovedayand V.I. Hanby (2006) The cooling potential of earth–air heat exchangers for domestic buildings in a desert climate. Building and Environment 41 (2006) 235–244
Alghannam, A.O. (2010). Mathematical Simulation of soil Subsurface Temperatures, Minufiya J. Agric. Res.Vol.36 No. 3
Chao, K. and R. S. Gates. (1996). Design of Switching Control Systems for Ventilated Greenhouses. Transactions of the ASAE 39(4):1513-1523.
Dole, J. M. and H. F. Wilkins. (1999). Floriculture : Principles and Species.
El-Sharkawy, M. A., J. H. Cock, and A. J. Zandbelt. (1986). Stomatal response to Air Humidity and its relation to Stomatal Density in a wide range of warm Climate Species. Photosynthesis Research. 137-149.Energy conference, 1992.
Enoch, H. Z. (1990). Crop Responses to Aerial Carbon Dioxide. Acta Horticulturae 268.
Grange, R.I., and D. W. Hand. (1987). A review of the Effect of the Atmospheric Humidity on the Growth of the Horticultural Crops. Journal of Horticultural Science. 62: 125-134.
Hand, D. W. (1982). CO2 enrichment the benetits and problems scientia Horticulturae 33: 14-43.
Hannan, J. J. (1998). Greenhouses: Advanced Technology for Protected Horticulture. CRC Press LLC, FL. heat loss calculation. heat transfer under heated ground surface, slab-on grade .
Ioslovich, I.; G. P. Seginer, and M. Borshchevsky (1995). Sub-Optimal Co2 Enrichment of Greenhouse, J. agrie. Engng Res. 60:117-136.
Ishihara, O. and Q. Zhang (1992). Cooling effects of earth tubes on dwellings.
Kimball, B. A., (1986). CO2 Stimulation of Growth and  Yield under Environmental Restrains. In Carbon Dioxide enrichment of Greenhouse Crops, Vol. II, Physiology Yield and Economics, CRC Press, Boca Raton, FL.
Kittas, C.; T. Bartzanas, and A. Jaffrin (2001). Greenhouse Evaporative Cooling: Measurement and Data Analysis, Transactions of the ASAE Vol. 44(3): 683-689.
Lee, I. B. and Short, T .H. (2001). Verification of Computational Fluid Dynamic Temperature Simulations in Full-Scale Naturally Ventilated Greenhouse, Transactions of the ASAE .V.44 (1): 119-127.
Nederhoff, E. M. (1988). Dynamic optimization of the CO2 Concentration in Greenhouse: An Experiment with cucumber (cucumber is sati us l.). Acta Hort. 229: 341-348.
Nerdhoff, E. M. and R. De Graaf. (1993). Effects of CO2 on Leaf Conductance and Canopy Transpiration of Greenhouse Grown Cucumber and Tomato. Journal of Horticulture Science. 68: 925-937
Qingysuan, Z. (1994). Development of residence with solar heating earth cooling, and air circulation. ASHRAE Transactions, 1994. p. 333–41
Sawhney, R. L and D. Buddhi (1999). Thanu NM. An experimental study of summer performance of a recirculation type underground airpipe air conditioning system. Building and Environment 1999;34:189–96
Sharan, G.; H. Prakash and R. Jadhav (2004).   Performance of Greenhouse Coupled to Earth-Tube-Heat-Exchanger in Closed-Loop Mode
Sodha, M. S.; A. K. Sharma and S. P. Singh (1985). Bansal Kumar A. Evaluation of an earth–air tunnel system for cooling/heating of a hospital complex. Building and Environment 1985;20(2):115–22.
Takakura, T. (1993). Climate Under Cover. Digital Dynamic simulation in Plant Bio-Engineering. Kluwer Academic Publishers, Norwell, MA.
Tobbitts, T. W. (1979). Humidity and Plants. Bioscience. 29:358-363.