Dual Flush Toilet Options
Due to federal regulations regarding water conservation, the national mandate is that newer toilets be designed to use 1.6 gallons of water per flush. This equates to a saving for each toilet of 10,500 gallons on average, per year. Dual flushing toilets can save an average of 6,000 gallons of water per flush annually. Many homeowners today are more conscious when choosing an efficient toilet due to the increasing awareness of water shortages and rising water cost. This makes the dual flushing toilet a smart choice.
The standard American design supports a 2 inch trapway that is connect to the siphoning tube. When the high volume of water rushes into the bowl forcing the water and waste into the siphoning tube, it creates a vacuum effect that sucks the waste and water from the bowl into the sewage system. The siphoning system works quiet well, however, it requires a larger volume of water in order to fill the siphoning tube and create the vacuum effect. The 1.6 gallons of water is not adequate enough to create the same effect which in turn creates a need for several flushes to clear the waste.
The dual flushing design is a newer technology and does not provide consumers with as many color and design options as a single flushing toilet. In addition, the dual flushing model is typically more expensive than the standard siphoning or single flushing models. Currently, there are three types of dual models available: power assisted, wash down and wash down siphonic. These models do not come with the standard handle as seen on most toilets. Rather, they are equipped with two buttons on the side or top that allows the user to choose the amount of water for each flush.
Kohler manufactures a power assisted dual flush model. This particular model features a small pump that is motorized which provides uniform strong flushes. It is much louder than other models and it is the least water efficient of the dual flush model designs. However, the punched holes in the rim provide less splashing than siphoning toilets and keeps the toilet cleaner and odor free longer.
Wash Down Siphonic Model
Made by Sterling, this model uses siphonic and wash down mechanisms for flushing. The flapper-less flushing valve and the design of the trap way creates a one flush operation that maximizes the use of gravity. Being designed with this valve system for durability, they offer more reliability for long term usage. The sanitary guards raised lip designed to support the tank provides for extra sanitation while preventing any liquid from entering underneath the tank. Water passes down through the rim in this system to cleanse the entire bowl of waste.
Wash Down Model
Caroma, Australia’s dual flush models are perhaps the most efficient when it comes to water usage. Unlike the siphoning system, the wash down is designed with a steeper pitch in the bowl and an open rim, allowing water to be rapidly pushed through the trap way. This process forces waste removal first and then water through the trap. The steepness of the sides of the bowl allow for it to reduce the amount of water needed per flush. The trap way measures approximately four inches, as opposed to the two inch wide traps in the siphoning models, helping reduce the possibility of clogging. About 95% of the time, only one flush is needed with the the Caroma toilets.