Checking for the WaterSense label is a good way to start when considering a low-flow toilet. After first-generation low-flow toilets got so much grief for sluggishness, the EPA added performance criteria to its grading system. The more than 600 high-efficiency toilets with the WaterSense stamp deliver water efficiency and good performance.
The EPA found no correlation between performance and prices on high-efficiency toilets, which range from about $200 to more than $4,000. But choosing among all the models can be overwhelming. It comes down to price range, style preference, and plumbing system, but understanding the competing technologies helps.
There are four basic options for toilets—listed here from most common to least—that meet or beat WaterSense standards.
- Single-flush gravity low-flow toilets. These are the most common, thanks to their low price and a simple design. Gravity transfers water from the tank to the bowl, but the minimum amount of water that’s used to flush has fallen from the standard 1.6 gallons to as low as 1.1. These are less costly and quieter than some other water-conserving options.
- Dual flush. These were the main source of early complaints about low-flow toilets, but improved hydraulics and bigger valves and trapways have reduced clogs and the need for multiple flushes. Most dual flushers are gravity toilets, and most use about 0.8 GPF for liquids and 1.6 for solids. They still meet WaterSense standards because the flush averages out water usage to about 1.28.
- Pressure-assist toilets. Pressurized air ensures a powerful flush with less water—from about 1.3 gallons to as low as 0.9. Pressure toilets require a home’s water pressure to rate at least 25 pounds per square inch (PSI). They’re noisier and tend to cost more than gravity toilets, but they get good consumer ratings and are some of the best sellers.
- Power-assist toilets. A pump powered by electricity forces water down at a higher velocity than a gravity toilet. These can be expensive and require special installation for the electrical components, but they can have highly effective flushes with just 0.8 to 1.1 GPF. Some models have a dual flush.
Go With the Flow
Sink faucets can waste water, especially when used for shaving and tooth brushing, and those ten or more years old may use as much as seven gallons per minute. Bathroom faucets minimize the flow with an aerator, usually a small screen in a cylinder that screws onto the nozzle. Air mixes with the water to power the flow.
WaterSense sets its lavatory sink maximum at 1.5 GPM with 60 PSI to ensure enough force to rinse razors and toothbrushes. Its minimum rate of 0.8 GPM at 20 PSI prevents manufacturers from selling faucets with wimpy flows.
If you’re not in the market for a new faucet, you can replace your old aerator with a more efficient one—flow rates are usually printed on the side. Hardware stores carry aerators for $5 to $10, and they’re easy to twist on.
New showerheads can provide a powerful spray with as little as 1.5 gallons a minute, and they offer water-saving innovations. Some have switches that allow you to shut off the water while soaping up without fiddling with the tap. One line, Evolve, makes low-flow heads starting around $40 that slow the water to a trickle when it gets hot, signaling when to jump in and minimizing the water and energy wasted if you wait too long.
Ensuring sufficient water pressure in a low-flow showerhead depends on the quality of the fixture as well as your plumbing. You can measure your water pressure with a gauge—about $10 at most hardware stores—or by timing how long it takes to fill a quart container: five seconds equals about 3 GPM, ten seconds about 1.5.
As with sink faucets, showerheads typically mix air into the water stream with an aerator to cut down on water usage. This can cool the water—raising energy costs—so WaterSense awards its label only to aerating showerheads with good hot-water delivery.
Non-aerating showerheads, which can also conserve water, form individual streams and may have adjustments for massaging effects. The flow can feel heavier than those from aerated streams.
Instant Hot Water
Running the tap until the water gets hot is one of the biggest sources of waste. The problem is that water cools in the pipe running from the water heater to the tap and must be flushed through to obtain hot water.
Tankless water heaters can reduce that problem, but only if they’re connected directly to each fixture; most systems use one heater for the whole house, which doesn’t result in much water savings.
Recirculation systems provide hot water instantly. A small pump connected to the fixture farthest from the water heater uses the cold-water line as a loop back to the heater to keep the water hot for the distant fixture and for all those in between. Most are electric—requiring an outlet under the sink—and are activated by a button, remote control, or a timer. Because they heat the water quickly and only when switched on, added energy costs are minimal. Some also include a thermostat that switches the pump off once sufficient hot water is in the pipe. But temperature-based systems don’t meet WaterSense criteria.
Area retailers Amicus Green Building Center and Eco-Green Living say the Metlund D’Mand System (about $450) is the best, but the Chilipepper CP6000 ($179.99) is also a bestseller.
Reusing household “gray water”—wastewater from sources other than the toilet—for flushing and watering the yard is another way to conserve. Gray-water systems divert water from showers, bathroom sinks, washing machines, and other sources, often purifying it so it won’t clog toilets or poison plants. Some versions are simple tanks that collect water, which must then be manually transferred to the toilet or garden. Others use electricity or pumps to redirect the water.
Another option is to install a sink on top of the toilet—Gaiam sells one for around $100—or to buy a dual toilet/sink such as Caroma’s Profile Smart (about $350 to $600), but these may require an awkward reach if there isn’t sufficient space around the commode.