Many of our engineering activities are targeted towards creating a safer and more comfortable environment for human activity.  We have developed modern technology to achieve this faster, cheaper and more efficiently.  The success criteria in project management circles of large infrastructure projects have previously been the triangle of quality, cost and time.  Yet the impact of our carbon emissions, especially due to our industrial activity of the past century has made us realize this was a warped view of the world.  Our planet has boundaries we should have recognized and respected.  This new knowledge puts a heavy burden of responsibility on our profession to act responsibly and fast to repair the damage we have caused.     The triangle of quality, cost and time is no longer adequate; there is now a fourth criteria we should consider; whole life carbon.   As a professional engineering body, ASHRAE should be questioning which of the current practices are in need of immediate change, in the Built Environment and beyond.  A couple of case studies will illustrate the dilemmas we all face, if we wish to leave a legacy to be proud of.


Mohammad leads the global tunnel ventilation business in Arup.  A Fellow of Institute of Mech Engineers, he has 40 years of consulting and R&D experience in tunnel ventilation and aerodynamics, Computational Fluid Dynamics (CFD), industrial ventilation, aircraft design and solar energy. With more than 40 publications, he has played key lead design and technical management roles in projects, and lectured extensively in aeronautical & industrial aerodynamics, CFD, ventilation, fluid machinery, pumping machines and systems.

Mohammad’s global experience in tunnel ventilation, M&E design & aerodynamics means he can apply lessons learnt from complex infrastructure projects in one city to another. Mohammad revised Chapter 15 “Enclosed Vehicular Facilities”, of the ASHRAE 2011 Handbook of HVAC Applications. He currently chairs the 19th International Symposium on Aerodynamics, Ventilation and Fire in Tunnels (ISAVFT 2022), taking place on Sep 28-30th in Brighton, UK, with the theme of sustainability. He is keen for his peers and colleagues to consider if the whole life carbon cost of all the large ventilation fan plants they design and build for tunnels and metros justifies the safety or comfort benefit they bring to the public; a fundamental question at the heart of all our engineering activity.

He maintains his strong interest in renewable energies – wind and solar energy.  He draws inspiration from nature, plants and animals in finding smart engineering design solutions for our environment. Mohammad is an avid researcher in the ways our ancestors used to keep themselves warm in winter and cool in summer, with a minimum carbon footprint and a healthier lifestyle. This inevitably raises the question of “Thermal comfort” as an ideal target in our HVAC designs, and whether the thresholds and guidance defined in our modern Engineering Standards are really suited to our current climate change predicament and really respect the planetary boundaries.