Applied Solar Energy

, Volume 45, Issue 1, pp 65–69 | Cite as

An experimental evaluation of copper, steel and polypropylene tubes in solar water heaters with thermosyphonic flow

  • M. R. Riazi
  • J. Razavi
  • A. Sadeghi
  • A. Javaheri


In this paper we report experimental results for the performance and rate of heat transfer in copper tubes in solar water heaters with thermosyphonic flow in continuation of experimental data reported in previous publications (Solar Energy, 2003, vol. 74, pp. 441–445, and Energy Sources, 1997, vol. 19, pp. 147–152). We also show a comparison between performances of three kinds of tubes: copper, polypropylene and steel under similar conditions. An analytical relation for calculation of rate of heat transfer in copper tubes is also presented in terms of Nusselt versus Reynolds and Prantdl numbers. A comparison of experimental data showed that performance of copper tubes is slightly better than polypropylene tubes while both of these tubes are significantly better than steel tubes.


Heat Transfer Nusselt Number Heat Transfer Rate Steel Tube Polypropylene Tube 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    A Brief History of the American Solar Water Heating Industry (Solar Energy Systems Inc., 2004); Articles/briefHistory.pdf.
  2. 2.
  3. 3.
    Frequently—Asked Questions about Solar Thermal Water Heating Systems, in Indian Renewable Energy Development Agency Limited (IREDA), 2004;
  4. 4.
    Chinnappa, J.C.V. and Gnanalingam, K., Performance at Colombo, Cylon, of a Pressurized Solar Water Heater of the Combined Collector and Storage Type, Solar Energy, 1973, vol. 15, pp. 195–204.CrossRefGoogle Scholar
  5. 5.
    Shitzer, A., Kalmanoviz, D., Zviring, Y., and Grossman, G., Experiments with a Flat Plate Solar Water Heating System, Solar Energy, 1979, vol. 22, pp. 27–35.CrossRefGoogle Scholar
  6. 6.
    Close, D.J., The Performance of Solar Water Heaters with Natural Circulation, Solar Energy, 1962, vol. 6, pp. 33–40.CrossRefGoogle Scholar
  7. 7.
    Ong, K.S., An Improved Computer Program for the Thermal Performance of a Solar Water Heater, Solar Energy, 1976, vol. 18, pp. 183–191.CrossRefGoogle Scholar
  8. 8.
    Chang, J.M., Leu, J.S., Shen, M.C., and Huang, B.J., A Proposed Modified Efficiency for Thermosyphonic Solar Heating Systems, Solar Energy, 2004, vol. 76, pp. 693–701.CrossRefGoogle Scholar
  9. 9.
    Riazi, M.R., Solar Water Heating Systems with Thermosiphonic Flow, in Solar Energy: New Research, Hough, T.P., Ed., New York, Hauppauge: Nova Sci. Publishers Inc., 2006, ch. 8, pp. 255–275; Hardcopy, ISBN: 1-59454-630-4/ Web: Scholar
  10. 10.
    Razavi, J. and Riazi, M.R., Experiments with Polypropylene Finned-Tube Solar Water Heating System in Thermosyphonic Flow, Energy Sources, 1994, vol. 16, no. 1, pp. 129–133.CrossRefGoogle Scholar
  11. 11.
    Riazi, M.R. and Razavi, J., Performance of Polypropylene and Steel Tubes in Solar Water Heaters with Natural Circulation, Energy Sources, 1997, vol. 19, no. 2, pp. 147–152.Google Scholar
  12. 12.
    Razavi, J., Riazi, M.R., and Mahmoodi, M., Rate of Heat Transfer in Polypropylene Finned Tube Solar Water Heating System, Solar Energy, 2003, vol. 74, no. 6, pp. 441–445.CrossRefGoogle Scholar
  13. 13.
    In Search of an All Plastic Solar Hot Water System for Domestic Hot Water (Solar Cities), 2007;
  14. 14.
    Holman, J.P., Heat Transfer, 8th ed., New York: McGraw-Hill, 1997.Google Scholar
  15. 15.
    Rowley, R.L., Wilding, W.V., Oscarson, J.L., et al., DIPPR Data Compilation of Pure Compound Properties, in Design Institute for Physical Properties (DIPPR), New York, NY: Taylor and Francis Publishing Co., 2002; Scholar

Copyright information

© Allerton Press, Inc. 2009

Authors and Affiliations

  • M. R. Riazi
    • 1
  • J. Razavi
    • 2
  • A. Sadeghi
    • 2
  • A. Javaheri
    • 2
  1. 1.Chemical Engineering DepartmentKuwait UniversityKuwaitKuwait
  2. 2.Chemical Engineering DepartmentSharif University of TechnologyTehranIran

Personalised recommendations