In the U.S., toilets account for 30% of indoor water use, but this is mostly due to their inefficient designs. So I was pleased to find the Stealth Ultra-High-Efficiency Toilet toilet by Niagara. This is probably the most water efficient flush toilet available for residential use. The Stealth (great name by the way) uses only 0.8 gallons per flush (GPF). This is much less than the average toilet, which uses around 2.5 gallons per flush. It’s also 37% less water than a “high-efficiency” toilet (those certified by EPA WaterSense).
The Stealth achieves this low rate because of its innovative hydraulic design. By harnessing the energy of water filling the tank, Stealth uses an air transfer system to pressurize the bowl’s trapway (the exit pipe). It creates swift, powerful flush using 0.8 gallons. Niagara, the manufacturer of the Stealth claims that the Stealth also the quietest toilet available.
I’m had two of these toilets installed in my house — and they flush better than most toilets I’ve encountered. They are also very quiet. Of course I’d prefer to have a composting squat toilet with bidet functionality.
Here’s a diagram of the toilet’s inner workings (click enlarge):
Here’s the Stealth home page.