Without even realizing it, Americans are flushing a valuable resource down their drains: hot water. On any given day, the average American blows through approximately 100 gallons of water, according to the U.S. Environmental Protection Agency. Of this, about 20 percent is heated.
Rather than let this hot commodity flow down the drain, International Wastewater Systems, in Burnaby, Canada, has created a water-reuse system that taps into this wasted resource and converts it into energy as heat. So far several construction projects in North America have teamed up with the company to install systems into their buildings.
How does it work? Simply put, the company’s Sewage SHARC system filters out the heat from wastewater and pumps it back into fresh water without any contamination. The process is called “sewage heat recovery.” As the wastewater goes down the drain, a system of pipes, filters, geothermal heat pumps, and heat exchangers captures and converts the energy to heat before pumping it back through a building as both a source to heat and cool the structure and its water system.
“It’s the ultimate renewable energy source,” says Lynn Mueller, president and CEO of International Wastewater Systems and inventor of the Sewage SHARC. “[Our system] never lets energy leave the building, but rather it continually reuses it.”
This continual loop ensures that warm water will be available around the clock, an added perk for anyone who has ever waited (and waited) for the water in their shower to go from frigid to toasty.
SHARCs in Action
The first construction project to employ the Sewage SHARC system was Seven35, a collection of 60 stacked townhomes in Vancouver, which received LEED Platinum certification from the U.S. Green Building Council. Completed in 2012, the building has already seen a net energy savings of 75.2 percent in terms of hot water production. The system has also reduced greenhouse gas emissions by 150 tons per year and provides 600 percent efficiency.
In other words, for every $1 invested into buying this particular Sewage SHARC, owners get $6 in return in energy savings. (Sewage SHARCs start at $250,000 for a small system and go up into the millions.)
Other projects in Canada that have added Sewage SHARCs include the Gateway Theater in Richmond, British Columbia, the first municipal building in North America to use sewage heat recovery technology, and Sail, a 172-unit condominium building near the University of British Columbia campus in Vancouver, a LEED-certified residential building.
Check out this behind-the-scenes video tour of the Gateway Theater and Sail systems.
Next page: Going with the Flow