Water Saving Toilets - More Efficient, Save Water
Today’s high-performing models remove waste as efficiently, or more efficiently, than conventional toilets while using much less water.
WaterSense has recently announced the first product specification that covers high-efficiency toilets (HETs)—those that use 1.28 gallons per flush (gpf) or less. With the announcement of the final HET specification, manufacturers, retailers, and distributors of water-efficient plumbing fixtures can use third-party certification to gain permission to use the WaterSense label on their products. In time, consumers will be able to recognize products with the WaterSense label as quality and high-performing water savers.
A variety of high-performing, low-flow toilets is available for residential use. Using different technologies, they provide a clean, efficient flush while meeting the 1.6 gpf maximum. The following is a rundown of the technology types with some benefits and drawbacks for each.
Gravity-assisted toilet
When the toilet is flushed, the flapper valve in the tank allows water to flow from the tank into the bowl, where the water and waste are pulled down the drain by gravity. Gravity-assisted models typically are the least expensive type of low-flow toilets, and they are able to work with low water pressure. A drawback is that they have the weakest flush.
Dual-flush gravity-assisted toilet
This toilet also uses gravity to remove waste, but it gives homeowners something more: one toilet with two flushing options. With the press of a button, a homeowner can choose a full flush of 1.6 gallons to remove solid waste or a half flush of 0.8 gallons to remove liquid waste. Relatively new to the U.S., dual-flush toilets have been widely used in Europe, the Middle East, the Far East, and Australia for years. While these have great water-saving potential, dual-flush toilets are currently the most expensive type of water saver.
Pressure-assisted toilet
The line pressure of water entering the toilet tank compresses trapped air within a sealed tank, until air pressure equals water pressure. When the toilet is flushed, the pressure of the compressed air reinforces the normal gravity flow. This increase in pressure works particularly well to remove waste with low amounts of water, although pressure-assisted toilets can be noisy, expensive, and require frequent repairs.
Vacuum-assisted toilet
Flushing this toilet activates vacuum chambers in the tank, which act like a siphon to pull water into the bowl. This design allows water to reach a greater area in the bowl, which keeps the bowl cleaner than other types of low-flow toilets. The vacuum-assisted toilet is quieter than pressure-assisted toilets, but the flush is weaker.