Skip to main content
Log in

Performance analysis of an integrated cooling system consisted of earth-to-air heat exchanger (EAHE) and water spray channel

  • Published:
Journal of Thermal Analysis and Calorimetry Aims and scope Submit manuscript


This study evaluates the cooling performance of a new hybrid system composing of an earth-to-air heat exchanger (EAHE) and a water spray channel to provide thermal comfort in Tehran, Iran. The inlet air temperature passing through the EAHE dissipates its heat to the surrounding soil and become slightly colder. To reach thermal comfort, the pre-cooled air flows upward through a channel spraying water downward and enters the living space. Considering the evaporative thermal comfort zone, the results showed that this system can meet comfort conditions for summer season Tehran. Moreover, according to the results, the cooling effectiveness of the proposed hybrid system is more than 100%, which means that the integrated system is capable of decreasing the air dry-bulb temperature below the inlet ambient wet-bulb temperature. Employing ground as a reliable source of alternative energy, the proposed cooling system can be considered an eco-friendly and energy-efficient system. Therefore, the introduced cooling system can be utilized as an alternative to conventional evaporative coolers or mechanical vapor compression systems while it can be considered an eco-friendly and energy-efficient system.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Subscribe and save

Springer+ Basic
EUR 32.99 /Month
  • Get 10 units per month
  • Download Article/Chapter or Ebook
  • 1 Unit = 1 Article or 1 Chapter
  • Cancel anytime
Subscribe now

Buy Now

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12

Similar content being viewed by others


A :

Annual amplitude of the ground surface temperature (°C)

A d :

Water droplet surface area (m2)

B :

Buoyancy (kg m s−2)

C d :

Drag coefficient

C pa :

Specific heat capacity of dry air (J kg−1 K−1)

C ps :

Specific heat capacity of soil (J kg−1 K−1)

C pma :

Specific heat capacity of moist air (J kg−1 K−1)

C pv :

Specific heat capacity of water vapor (J kg−1 K−1)

C pw :

Specific heat capacity of water (J kg−1 K−1)

D :

Drag force (kg m s−2)

d d :

Diameter of water droplet (m)

f :

Friction factor

G :

Gravity force (kg m s−2)

h a :

Heat transfer coefficient of air (W m−2 K−1)

h m :

Mass transfer coefficient (kg m−3 s−1)

i a :

Enthalpy of dry air (kJ kg−1)

i ma :

Enthalpy of moist air (kJ kg−1)

i v :

Enthalpy of evaporation of water (kJ kg−1)

i fgw0 :

Enthalpy of evaporation of water at 0 °C (kJ kg−1)

i masw :

Enthalpy of saturated air (kJ kg−1)

k a :

Thermal conductivity of air (W m−1 K−1)

k s :

Thermal conductivity of soil (W m−1 K−1)


Lewis factor

\(\dot{m}_{\text{a}}\) :

Mass flow rate of air (kg s−1)

m d :

Mass of water droplet (kg)

\(\dot{m}_{\text{w}}\) :

Mass flow rate of water (kg s−1)


Nusselt number

N d :

Number of water droplets in a control volume


Prandtl number

Q s :

Heat transfer from soil (W)

Q :

Total heat transfer (W)

Q e :

Evaporative heat transfer (W)

Q c :

Convective heat transfer (W)

r 1 :

Pipe inside radius (m)

R tot :

Overall thermal resistance (m2 K W−1)


Reynolds number

T :

Ground temperature (°C)

T m :

Mean annual temperature of the ground (°C)

T a :

Temperature of air (°C)

T avg :

Average temperature (°C)

T wb :

Wet-bulb temperature of air (°C)

U d :

Internal energy of water droplet (J)

U a :

Velocity of air (m s−1)

U d :

Velocity of water droplets (m s−1)

X, Y, Z :

Coordinate system (m)

τ 0 :

Time delay (s)

α s :

Thermal diffusivity of soil (m2 s−1)

ε :

Cooling effectiveness

ω a :

Absolute air humidity

ω sw :

Absolute humidity of saturated air

ρ a :

Density of air (kg m−3)

ρ s :

Density of soil (kg m−3)

ρ w :

Density of water (kg m−3)


  1. Misra R, Bansal V, Das Agarwal G, Mathur J, Aseri T. Thermal performance investigation of hybrid earth air tunnel heat exchanger. Energy Build. 2012;49:531–5.

    Article  Google Scholar 

  2. Sheikhani H, Barzegarian R, Heydari A, Kianifar A, Kasaeian A, Grόf G, Mahian O. A review of solar absorption cooling systems combined with various auxiliary energy devices. J Therm Anal Calorim. 2018;134(3):2197–212.

    Article  CAS  Google Scholar 

  3. Darkwa J, Kokogiannakis G, Magadzire CL, Yuan K. Theoretical and practical evaluation of an earth-tube (E-tube) ventilation system. Energy Build. 2011;43:728–36.

    Article  Google Scholar 

  4. Maerefat M, Haghighi AP. Passive cooling of buildings by using integrated earth to air heat exchanger and solar chimney. Renew Energy. 2010;35:2316–24.

    Article  Google Scholar 

  5. Heidarinejad G, Khalajzadeh V, Delfani S. Performance analysis of a ground-assisted direct evaporative cooling air conditioner. Energy Build. 2010;45:2421–9.

    Article  Google Scholar 

  6. Maerefat M, Haghighi AP. Natural cooling of stand-alone houses using solar chimney and evaporative cooling cavity. Renew Energy. 2010;35:2040–52.

    Article  Google Scholar 

  7. Maerefat M, Ahmadi S, Haghighi AP. Investigation and performance analysis of a hybrid cooling system of air underground channel and direct evaporative cooler. Modares Mech Eng. 2015;15(5):137–44.

    Google Scholar 

  8. Afrand M, Shahsavar A, Talebizadeh PS, Sopian K, Salehipour H. Energy and exergy analysis of two novel hybrid solar photovoltaic geothermal energy systems incorporating a building integrated photovoltaic thermal system and an earth air heat exchanger system. Sol Energy. 2019;188:83–95.

    Article  Google Scholar 

  9. Gilani N, Doustani AH, Shirmohammadi R. Developing of a novel water-efficient configuration for shower cooling tower integrated with the liquid desiccant cooling system. Appl Therm Eng. 2019;154:180–95.

    Article  Google Scholar 

  10. Heidarinejad G, Pasdarshahri H. Potential of a desiccant-evaporative cooling system performance in a multi-climate country. Int J Refrig. 2011;34:1251–61.

    Article  CAS  Google Scholar 

  11. Heidarinejad G, Farmahini MF, Delfani S. Investigation of a hybrid system of nocturnal radiative cooling and direct evaporative cooling. Build Environ. 2010;45:1521–8.

    Article  Google Scholar 

  12. Haghighi AP, Mohabbati S. Performance analysis of wind catcher integrated with shower cooling system to meet thermal comfort conditions in buildings. J Cleaner Prod. 2017;148:452–66.

    Article  Google Scholar 

  13. Aljubury MA, Ridha HD. Enhancement of evaporative cooling system in a greenhouse using geothermal energy. Renew Energy. 2017;111:321–31.

    Article  Google Scholar 

  14. Bansal V, Misra R, Das Agrawal G, Mathur J. Performance analysis of integrated earth–air-tunnel-evaporative cooling system. Energy Build. 2012;47:525–32.

    Article  Google Scholar 

  15. Chen H, Peng Y, Wang Y. Thermodynamic analysis of hybrid cooling system integrated with waste heat reusing and peak load shifting for data center. Energy Convers Manag. 2019;183:427–39.

    Article  Google Scholar 

  16. Gandomkar A, Saidi MH, Shafii MB, Vandadi M, Kalan K. Visualization and comparative investigations of pulsating ferro-fluid heat pipe. Appl Therm Eng. 2017;116:56–65.

    Article  CAS  Google Scholar 

  17. Ramezanizadeh M, Alhuyi Nazari M, Ahmadi MH, Chao KW. Experimental and numerical analysis of a nanofluidic thermosyphon heat exchanger. Eng Appl Comput Fluid Mech. 2018;13(1):40–7.

    Google Scholar 

  18. Ahmadi MH, Ramezanizadeh M, Alhuyi Nazari M, Lorenzini G, Kumar R, Jilte R. Applications of nanofluids in geothermal: a review. Math Model Eng Probab. 2018;5(4):281–5.

    Google Scholar 

  19. Ozgener L. A review on the experimental and analytical analysis of earth to air heat. Renew Sustain Energy Rev. 2011;15:4483–90.

    Article  CAS  Google Scholar 

  20. Kusuda T, Archenbach P. Earth temperature and thermal diffusivity at selected stations in the United States. ASHRAE Trans. 1965;71:61–75.

    Google Scholar 

  21. De Paepe M, Janssens M. Thermo-hydraulic design of earth-air heat exchangers. Energy Build. 2003;35:389–97.

    Article  Google Scholar 

  22. Xiaoni Q, Zhenyan L. Further investigation on the performance of a shower cooling tower. Energy Conv Manag. 2008;49:570–7.

    Article  Google Scholar 

  23. González Pedraza OJ, Pacheco Ibarra JJ, Rubio-Maya C, Galván González SR, Rangel Arista JA. Numerical study of the drift and evaporation of water droplets cooled down. Appl Therm Eng. 2018;142:292–302.

    Article  Google Scholar 

  24. Morsi SA, Alexander AJ. An investigation of particle trajectories in two-phase flow systems. J Fluid Mech. 1972;55(2):193–208.

    Article  Google Scholar 

  25. Gilani N, Parpanji F. Parametric study on the outlet water temperature in a shower cooling tower and its application in different Iranian provincial capitals. Int J Therm Sci. 2018;124:174–86.

    Article  Google Scholar 

  26. Bosnjakovic F. Technical thermodynamics. 1st ed. New York: Holt, Rinehart and Winston; 1965.

    Google Scholar 

  27. Qi X, Liu Z, Li D. Performance characteristics of a shower cooling tower. Energy Convers Manag. 2007;48:193–203.

    Article  CAS  Google Scholar 

  28. Dhaliwal A, Goswami D, Das G. Heat transfer analysis inenvironmental control using an underground air tunnel. J Sol Energy Eng. 1985;5:107–41.

    Google Scholar 

  29. Xiaoni Q, Zhenyan L, Dandan L. Prediction of the performance of a shower cooling tower based on projection pursuit regression. Appl Therm Eng. 2008;28:1031–8.

    Article  Google Scholar 

  30. Heidarinejad G, Delfani S. Selection of outdoor design condition instruction for designing of HVAC systems in cities of Iran. Tehran: Build Housing Res Cent Pub; 2007.

    Google Scholar 

  31. Misra R, Bansal V, Das Aarawal G, Mathur J, Aseri TK. CFD analysis based parametric study of derating factor for earth air tunnel. Appl Energy. 2013;103:266–77.

    Article  Google Scholar 

  32. Benhammoua M, Draouib B. Parametric study on thermal performance of earth-to-air heat. Renew Sustain Energy Rev. 2015;44:348–55.

    Article  Google Scholar 

  33. Zhao Y, Li R, Ji C, Huan C, Zhang B, Liu L. Parametric study and design of an earth-air heat exchanger using model. Appl Therm Eng. 2019;148:838–45.

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations


Corresponding author

Correspondence to Sadegh Ahmadi.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Ahmadi, S., Irandoost Shahrestani, M., Sayadian, S. et al. Performance analysis of an integrated cooling system consisted of earth-to-air heat exchanger (EAHE) and water spray channel. J Therm Anal Calorim 143, 473–483 (2021).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: