Product Review

Niagara's Innovative Ultra-High-Efficiency "Stealth" Toilet

Pressure-assist toilets compress air when a sealed vessel refills afterflushing, and that compressed air pushes water at high velocity through the flush valve and into the toilet bowl. These toilets work well, consuming as little as 1.0 gpf (3.8 lpf).

Niagara has taken pressure-assist technology and turned it on its head. Like pressure-assist toilets, the Stealth has an inner tank that fills with water after flushing, but instead of generating pressure in the top of the chamber, the air at the top of this inner tank is pushed through a transfer tube into the trapway, forming a large air bubble that fills about 12 inches of the space between the water in the toilet bowl and the water further down the trap (see diagram). This bubble exerts enough force to raise the water level in the bowl, making the toilet’s “water spot,” or water surface area, comparable to that of a 1.28 gpf model.

Published June 29, 2010

Ehrlich, B. (2010, June 29). Niagara's Innovative Ultra-High-Efficiency "Stealth" Toilet. Retrieved from