Water and Energy are interconnected throughout their lifecycles (Water-Energy Nexus); while energy efficiency has dominated the conversation for many years, Water Stewardship is gaining momentum among water shortages and increased costs.
There are multiple applications for Water Harvesting in commercial buildings, both for water collection and reuse.
HVAC Condensate is a great source of clean water that can be easily reused. In Air Handlers and Fan Coils, moisture condenses as the air cools and drains out of the unit. Rainwater is the relatively “clean” water collected from building roofs during storms, which can be a significant amount of water! Both HVAC Condensate and Rainwater typically combine filtration and UV to treat the water before reuse.
Stormwater is the more “dirty” water collected from landscapes, sidewalks, and parking areas during a storm. Grey Water is gently used water from sinks, showers, laundries, etc.
Stormwater and Grey water require more robust filtration and treatment than Condensate and Rainwater prior to reuse.
Cooling Tower Makeup is a great way to lower water costs by reducing makeup water from the municipal supply, as cooling towers can be the largest consumer of water on a commercial property.
Irrigation is another great use for harvested water; like cooling tower makeup it will lower municipal water consumption.
Toilet Flushing can be an option for water reuse but requires additional non-potable piping in the building.
In any application, if the water harvesting pump system is the primary supply of water, a municipal water makeup system must be included in the event the harvested water is not enough to keep up with the system demand.