The Dubai International Airport may be the largest ozonated HVAC system in the world with air treatment in all of their buildings.

Early in the airport’s growth, the airport’s manager felt that superior air treatment was required to give a clean, fresh air to accommodate the many international passengers who visit their establishment. It was decided to try the novel approach of ozonation of the inside air in preference over the traditional approach of carbon filtering.  Expectations, results in terms of passenger satisfaction and operating economics, have been exceeded after only a short period of time.

The ozone is injected into the central air conditioning system. The ozone generators are controlled by sensors activated by excessive VOC concentrations and turned off by excess ozone concentration sensors. Carbon dioxide sensors call for makeup air if the carbon dioxide concentration exceeds a standard set-point. All systems and components are controlled by a computerized building control system. The ozone monitors keep the ozone concentrations in the occupied areas to less than .05 ppm. The VOCs to be minimized by the ozone treatment include cigarette smoke, jet fuel and exhaust fumes in the makeup air, building chemical fumes and more. The conditioned air residence time in the passenger areas is about 15 minutes or about the half- life of the ozone in such environments. Because the ozone concentration drops about 90% from supply ducts to return ducts instead of about a 50% drop predicted by half-life, we can see that much of the ozone has reacted with VOCs.

An unexpected finding was that the makeup air could be cut by 50% without compromising the carbon dioxide concentration criterion. The ozone is destroying the VOCs sufficiently to significantly reduce the makeup air without reducing the building’s air perceived quality. This translates to great energy savings because cooling the very hot makeup air requires large amounts of energy. The indicated energy saving should recover the cost of the ozone equipment in about one year.

After several years, the main observations of the use of ozone are:

  • Passengers and employees note a pleasing air quality without the distinct smells that are often found in busy airports.
  • The savings of ozone replacing carbon filters are very large. Carbon filters have high replenishment costs and occupy a lot of valuable space.
  • The energy savings in reducing the makeup air requirement are significant.
  • Other HVAC system maintenance costs are reduced such as less cleaning of the ducts due to virtually no mold and mildew accumulation.

The airport was recently voted a World’s Favorite Airport by readers of Conde Nast Traveler magazine.

Source: Ozone Monitoring and Control For Air Treatment Systems, Lawrence B. Kilham, 

Eco Sensors, Inc., Santa Fe, New Mexico, USA

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