Vernacular to Contemporary | PDEC | An ‘Adaptation’ – Part II

Last week in Part I, we introduced a Vernacular to Contemporary Adaptation – PDEC – Passive Downdraft Evaporative Cooling. A Vernacular ventilation strategy – Wind Catchers, which is being adapted to Contemporary buildings. We also looked at diagrams explaining the 3 main principles in this Adaptation.


This week we look at Pros and Cons of this technology for Contemporary use.


1) Energy Saving

a) Decrease cooling demand

Temperature Drops of upto 13oC can be achieved1. When the outdoors sizzle at close to 44oC, the indoors are at around 30oC.

Night Ventilation using PDEC towers decreases cooling demand and operating time of the primary cooling system the following day3.

b) Less Fluctuations

Indoor Temperature fluctuations of around 3-4oC can be seen over 24 hours, when the outside Temperature fluctuations are between 14-17oC1.


2) Cost/ Applicability

a) Short Payback Period

Electrical Consumption savings helped achieve payback of additional capital cost in less than 1 year for the Torrent Research Centre, Ahmedabad.1

b) Can be used in new / existing buildings with simple construction elements at relatively low cost.


3) Location

a) Applicable in areas without wind

As Air movement is created by momentum transfer from water to air and density difference; the technology can be applicable in areas without wind 4, 5.


4) Cleaner Air

a) Evaporative Cooling

The air is cleaned during the evaporative cooling process 6.


Cons –

1) Capacity

The cooling capacity maybe insufficient in certain cases, and could need conventional cooling as well 4.


2) Cost/ Applicability

a) High Water Consumption 6.

b) Short life of Water Pads


3) Climate Dependency

a) Works best in Hot & Dry Conditions

The technology maybe most effective in hot and dry conditions. However, buildings can be designed to adapt to other conditions and seasons. For example, in the Torrent Research Centre, the system operates normally in the dry season. In the monsoons, the water spray is not used, whereas in Winters, the openings to the rooms and shafts can be controlled (opened or closed) by the occupants 1, 4, 6.


sum up


How do You feel about this Vernacular ‘Adaptation’ for Contemporary Buildings?

Have you come across other such Adaptations?

What are your thoughts on the Practicality of this Technology? Let us know!


Video Source: 

The rchitecture Gazette

Music Source:

“Virtutes Instrumenti” Kevin MacLeod (
Licensed under Creative Commons: By Attribution 3.0 License


  1. A&D, ADEME, INDé (Mohan S.), Palacios D. | Case Study II: The Torrent Research Centre in Ahmedabad, by Abhikram. Architecture & Developpement.
  2. Zaveri P, Patel N. Abhikram | Projects | Torrent Research Centre, Ahmedabad.
  3. Paanchal JB, Mehta N. “A Review on Design of Passive Down Draft Evaporative Cooling in Commercial building.” 2017;3(2).
  4. Bowman, N. T., Eppel, H., Lomas, K. J., Robinson, D., and Cook, M. J. “Passive Downdraught Evaporative Cooling I. Concept and Precedents.” Indoor + built environment 9.5 (2000):284-290.
  5. Etzion, Y., Pearlmutter, D., Erell, E., and Meir, I. A. “Adaptive architecture: Integrating low-energy technologies for climate control in the desert.” Automation in construction 6.5 (1997):417-425.Ford, B. “Passive downdraught evaporative cooling: principles and practice.” Environmental Design. Architectural Research Quarterly 5, Cambridge University Press (2001) : 271-280.
  6. Givoni, B. “Performance of the Shower Cooling Tower in Different Climates.” Renewable Energy, 10, 2/3 (1997):173-178.

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