Condensate Water Collection for an Institutional Building in Doha, Qatar: An Opportunity for Water Sustainability

Abstract

In almost all modern buildings today, HVAC equipment is used to provide a conditioned indoor environment while using large amounts of energy to cool, filter, and dehumidify the air in these structures. This is especially true for buildings located in hot and humid climates around the world. International engineering organizations, such as ASHRAE, have developed indoor air quality standards which stipulate substantial requirements for fresh outside air to be introduced into a building’s air conditioning system. Internal loads and additional outside ventilation air all generate considerable latent loads on these systems and exacerbate the already difficult moisture control problem. A manifestation of this load is the liquid water condensate that is typically drained away from the air conditioning equipment and routed to the nearest sanitary drain. This project investigated sustainability issues associated with the collection and storage of this condensate water from selected air conditioning equipment for an institutional building located on the Education City Campus in Doha, Qatar. Simplified modeling of the condensation potential from the existing air conditioning systems, means for tapping into existing condensate drainage systems for re-routing to a storage facility, metering of collected condensate water, and potential impact for this water capture and re-use technique were studied. This project demonstrated the potential to capture over 6 million liters (1.6 million gallons) of condensate water each year from the air conditioning systems for this building.