Thermal systems are inherently energy-intensive, more so than lighting, and thermal management is a growing area of innovation for the built environment. The water-side of these thermal systems (the “water-energy nexus”) represents very large opportunities for energy efficiency gains.
Most buildings greater than 10 stories tall require “wet” cooling towers for air-conditioning as part of their HVAC (heating, ventilation and air-conditioning) systems. HVAC chillers are equipment delivering air-conditioning to buildings, and the cooling towers remove heat from chillers by cycling and evaporating water.
Because of the nature of water, evaporation is an efficient way to dump large amounts of heat, but evaporation also concentrates water progressively. This creates the need for water treatment to prevent fouling in chillers and cooling towers along with major energy losses. Chemical treatment programs for cooling water are essential but, since the banning of chromates in the 1970’s, can rarely keep chillers completely clean and free of fouling-related energy losses..