New York green contractors and homeowners are applying a modern innovation to an age-old technology.
The body creates two types of waste, so the logical approach is a toilet capable of two types of flush: a gentle gurgle for liquid waste and a more generous gush for solid waste, resulting in water conservation through more efficient performance.
Dual flush toilets originated in Australia and have gained popularity through government rebates for homeowners converting from old single flush toilets. In America, dual flush toilets are also catching on among conservation-conscious green contractors and policy-makers.
The Energy Policy Act of 1992 mandates that toilets must use no more than 1.6 gallons per flush. Dual flush toilets push this limit further by using only a half flush, less than a gallon, for liquid waste and reserving the full flush for solid wastes.
Dual flush toilets are also widely available for the homeowner: leading brands like Kohler and American standard offer many models, and while dual flush toilets tend to be more expensive and complex than their single flush cousins, Amazon now sells retrofitting kits that allow homeowners to convert their own toilets for as little as $22.95.
As a practical downside dual flush toilets generally need more frequent cleaning, but homeowners can also refer to a toilet’s Maximum Performance (MaP) score to purchase a toilet that meets their needs. Scores range from 250-1000: the higher the number, the more powerful the flush. A high efficiency toilet, which can use as little as 1 gallon per flush, is required by the EPA to operate at a minimum MaP score of 350, sufficient for daily household use.
Let’s calculate each toilet’s daily water consumption, assuming the average person defecates once and urinates six times during the course of the day.
Single flush: 7 flushes x 1.6 gal/flush = 11.2 gal
Dual flush: (1 flush x 1.6 gal/flush) + (6 flushes x 0.8 gal/flush) = 6.4 gal
High efficiency: 7 flushes x 1 gal/flush = 7 gal
The dual flush toilet still wins out in overall efficiency (0.91 gal/flush), but only when used properly. High efficiency toilets are another great option that simplify the process and can potentially be cheaper to purchase. Either way, as green-conscious builders and homeowners in America struggle to catch up to Australian and European counterparts, expect to see many more of these innovative toilets replacing standard ones in both public buildings and private homes.
Harvard installed dual-flush toilets as part of their commitment to moving toward sustainable facilities and maintenance. Click through for more examples of energy-efficient and green technology in Harvard’s buildings.