It’s been twenty-five years since the government mandated that all new toilets sold in the U.S. be low-flow toilets. Yet often homeowners still view these water-efficient fixtures with a wary eye. It’s hard to imagine that a toilet that uses only 1.6 gallons per flush, the low-flow standard, can possibly do as good a job as that vintage porcelain faithful that uses a hefty three-to-seven gallons.
Fortunately, engineering and hydraulics triumph. Check out how a low-flow toilet works.
Gravity-Fed Low-Flow Toilets
When the low-flow standard was first introduced, homeowners had good reason to be wary. The first low-flow toilets simply reduced the size of the water tank without taking into account if the decrease in flush volume would still clean as efficiently. It often didn’t, which meant homeowners were double-flushing, defeating the entire purpose of the new standards.
Toilet manufacturers quickly made adjustments. Without changing the usual gravity-fed mechanism, they upgraded the toilet in three ways to better take advantage of flow:
- The drain outlet is more centered in the bowl rather being at the back as in older toilets
- The flush valve has a greater diameter, releasing more water quickly and with more force
- The bowl itself is designed so that more water rests at the front end, increasing the wash where it’s needed most
The result is a toilet very much like the vintage porcelain faithful that uses less water but works just as well.
Pressure-Assisted Low-Flow Toilets
Pressure-assisted toilets look just like your regular toilet except for inside the tank, where you won’t see water but only a sealed plastic vessel. Within that vessel is a mechanism that, upon flushing, emits a burst of compressed air to push water more forcibly into the bowl. Some pressure-assisted toilets use electric pumps instead, but the result is the same: The increased force aids in cleaning the bowl as well as pushing water and waste deeper through your sewer pipes.
Pressure-assisted low-flow toilets tend to be a little noisier than gravity-fed ones, but because of how efficiently they clean, they may also use less water per flush.
Toilet flushing consumes nearly 40% of the water use in a typical home. Replacing your old, inefficient toilets with new low-flow toilets is an easy and effortless way to save water, energy, and money.