Performance Evaluation of a Mechanical Draft Cross Flow Cooling Towers Employed in a Subtropical Region

  • Palanisamy MuthukumarEmail author
  • Bukke Kiran Naik
  • Amarendra Goswami
Original Contribution


Mechanical draft cross flow cooling towers are generally used in a large-scale water cooled condenser based air-conditioning plants for removing heat from warm water which comes out from the condensing unit. During this process considerable amount of water in the form of drift (droplets) and evaporation is carried away along with the circulated air. In this paper, the performance evaluation of a standard cross flow induced draft cooling tower in terms of water loss, range, approach and cooling tower efficiency are presented. Extensive experimental studies have been carried out in three cooling towers employed in a water cooled condenser based 1200 TR A/C plant over a period of time. Daily variation of average water loss and cooling tower performance parameters have been reported for some selected days. The reported average water loss from three cooling towers is 4080 l/h and the estimated average water loss per TR per h is about 3.1 l at an average relative humidity (RH) of 83%. The water loss during peak hours (2 pm) is about 3.4 l/h-TR corresponding to 88% of RH and the corresponding efficiency of cooling towers varied between 25% and 45%.


Water cooled condenser Cross-flow cooling tower Efficiency Water loss 



Air conditioning


Ton of refrigeration


Relative humidity


Theoretical water loss


Overall theoretical water loss


Actual water loss

Special Symbols


Specific humidity, kg/kg of dry air


Mass flow rate, l/s


Temperature difference, °C


Efficiency, %



Hot water inlet


Cold water outlet


Wet bulb temperature


Dry bulb temperature


Water vapour


Chilled water



The authors express their sincere thanks to IIT Guwahati, Sterling and Wilson Company private Limited, Kolkata Branch and Trane Company private limited, Kolkata Branch for providing the necessary technical support during the experiment.


  1. 1.
    M. Lucasa, P.J. Martinez, A. Viedma, Experimental determination of drift loss from a cooling tower with different drift eliminators using the chemical balance method. Int. J. Refrig. 35, 1779–1788 (2012)CrossRefGoogle Scholar
  2. 2.
    W.H. Walker, W.K. Lewis, W.H. McAdams, Principles of Chemical Engineering (McGraw-Hill, New York, 1923)Google Scholar
  3. 3.
    V.D.I. Merkel, Verdunstungskiihlung, vol. 275 (Forschungsarbeiten, Berlin, 1925)Google Scholar
  4. 4.
    H.B. Nottage, Merkel’s cooling diagram as a performance correlation for air-water evaporative cooling systems. ASHRE Trans. 47, 429–448 (1941)Google Scholar
  5. 5.
    Lichtenstein, Performance and selection of mechanical-draft cooling towers. ASME Trans. 65, 779–787 (1943)Google Scholar
  6. 6.
    H.S. Mickley, Design of forced draft air conditioning equipment. Chem. Eng. Prog. 45, 739–745 (1949)Google Scholar
  7. 7.
    W.M. Simpson, T.K. Sherwood, Performance of small mechanical draft cooling towers. Refrig. Eng. 52(535–543), 574–576 (1946)Google Scholar
  8. 8.
    L.D. Berman, Evaporative Cooling of Circulating Water, vol. 2 (Pergamon, Bergama, 1961)Google Scholar
  9. 9.
    U.J.L. Threlkeld, Thermal Environmental Engineering, vol. 11 (Prentice-Hall, New Jersey, 1970)Google Scholar
  10. 10.
    G. Yadigaroglu, E.J.Pastor, An Investigation of the Accuracy of the Merkel Equation for Evaporative Cooling Tower Calculations, ASME Paper 74, (1974)Google Scholar
  11. 11.
    A. Whillier, A fresh look at the calculation of performance of cooling towers. ASHRAE Trans. 82, 269–282 (1976)Google Scholar
  12. 12.
    A.N. Nahavandi, R.M. Kershah, B.J. Serico, The effect of evaporation losses in the analysis of counter flow cooling towers. Nucl. Eng. Des. 32, 29–36 (1975)CrossRefGoogle Scholar
  13. 13.
    F. Osterle, On the analysis of counter-flow cooling towers. Int. J. Heat Mass Transf. 34, 1313–1316 (1991)CrossRefGoogle Scholar
  14. 14.
    J.E. Braun, S.A. Klein, J.W. Mitchell, Effectiveness models for cooling towers and cooling coils. ASHRAE Trans. 95, 164–174 (1989)Google Scholar
  15. 15.
    J.W. Suthedand, Analysis of mechanical draught counterflow air/water cooling towers. Int. J. Heat Transf. 105, 576–583 (1983)CrossRefGoogle Scholar
  16. 16.
    M.A. Bernier, Cooling tower performance: theory and experiments. ASHRAE Trans. 100, 114–121 (1994)Google Scholar
  17. 17.
    M.A. Bernier, Thermal performance of cooling towers. ASHRAE J. 37, 56–61 (1995)Google Scholar
  18. 18.
    M.A. Nimr, Modeling the dynamic thermal behavior of cooling towers containing packing materials. Heat Transf. Eng. 20, 91–96 (1999)CrossRefGoogle Scholar
  19. 19.
    C. Ren, An analytical approach to the heat and mass transfer processes in counterflow cooling towers. ASME J. Heat Transf. 128, 1142–1148 (2006)CrossRefGoogle Scholar
  20. 20.
    A.S. Jose, The use of thermo-fluid dynamic efficiency in cooling towers. Heat Transf. Eng. 23, 22–30 (2002)CrossRefGoogle Scholar
  21. 21.
    M. Kintner-Meyer, A.F. Emery, Cost-optimal analysis of cooling towers. ASHRAE Trans. 100, 92–101 (1994)Google Scholar
  22. 22.
    J.R. Khan, S.M. Zubair, Performance characteristics of counter flow wet cooling towers. Int. J. Energy Conversat. Manag. 44, 2073–2091 (2002)CrossRefGoogle Scholar
  23. 23.
    S.P. Fisenko, A.A. Brin, A.I. Petruchik, Evaporative cooling of water in a mechanical draft cooling tower. Int. J. Heat Mass Trans. 47, 165–177 (2004)CrossRefzbMATHGoogle Scholar
  24. 24.
    S.J. Arceivala, Water Conditioning for Cooling Towers, Spray Ponds etc (Central Public Health Engineering Research Institute, Nagpur, 1971)Google Scholar
  25. 25.
    C.G.Nirmal, Air-cooled: myths and facts. Air Cond. Refrig. J., 03–15 (2003)Google Scholar

Copyright information

© The Institution of Engineers (India) 2018

Authors and Affiliations

  • Palanisamy Muthukumar
    • 1
    Email author
  • Bukke Kiran Naik
    • 1
  • Amarendra Goswami
    • 2
  1. 1.Department of Mechanical EngineeringIndian Institute of Technology GuwahatiGuwahatiIndia
  2. 2.Engineering SectionIndian Institute of Technology GuwahatiGuwahatiIndia

Personalised recommendations