Thursday, September 24, 2009

Water saving with dual flush toilets

I was up in Calgary, Canada for vacation this summer, and was very happy to see all of the energy conservation measures being put to practice in homes, hotels and businesses. One thing that really caught my eye, were the dual flush toilets, which were even evident in the airport. With a dual flush, you pull the lever up for liquid for a half flush, down for solid for a full flush – thus cutting you water usage markedly. Old style toilets use about five gallons per flush, the new low flows use about 1.6 gallons. In either case, this amount can be cut in half most of the time using the dual flush.

Replacing a perfectly good toilet just to have a dual flush seems impractical, and, although our local recycle center, like many others, does accept, and consequently pulverize donated toilets, this still does not seem like an energy conscious move. The solution, a dual flush conversion kit that can change any toilet into a dual flush, even low flows. We now carry this item on our website,, in the water section.

Here is a some info on how dual flush toilets operate, sourced from the “How Stuff Works” website.

The way water is used to remove waste from the bowl has a lot to do with how much water is needed to get the job done. Standard toilets use siphoning action, a method that employs a siphoning tube, to evacuate waste. A high volume of water entering the toilet bowl when the toilet's flushed fills the siphon tube and pulls the waste and water down the drain. When air enters the tube, the siphoning action stops. Dual flush toilets employ a larger trapway (the hole at the bottom of the bowl) and a wash-down flushing design that pushes waste down the drain. Because there's no siphoning action involved, the system needs less water per flush, and the larger diameter trapway makes it easy for waste to exit the bowl. Combined with the savings from using only half-flushes for liquid waste, the dual flush toilet design can save up to 68 percent more water than a conventional low flow toilet [source: Green Building].

The dual flush toilet uses a larger diameter trapway that doesn't clog as often as a conventional toilet, needs less water to flush efficiently and saves more water than a low flow toilet when flushing liquid waste.


Aviad said...

funny, I just spent a week in France and Israel and found that ALL the toilets have 2 options to flash. As I understood, it is a must and comes with any toilet you buy.
It also seems that sustainability in these countries is more organic in the mean that it is rooted in the people's traditions.
Thank you for the interesting post,

pottygirl said...

Toilets account for approx. 30% of water used indoors. By installing a Dual Flush toilet you can save between 40% and 70% of drinking water being flushed down the toilet, depending how old the toilet is you are going to replace.
If you are serious about saving water, want a toilet that really works and is affordable, I highly recommend installing a Dual Flush toilet. Caroma toilets offer a patented dual flush technology consisting of a 0.8 Gal flush for liquid waste and a 1.6 Gal flush for solids. On an average of 5 uses a day (4 liquid/ 1 solid) a Caroma Dual Flush toilet uses an average of 0.96 gallons per flush. The new Sydney Smart uses only 1.28 and 0.8 gpf, that is an average of 0.89 gallons per flush. This is the lowest water consumption of any toilet available in the US. Caroma, an Australian company set the standard by giving the world its first successful two button dual flush system in the nineteen eighties and has since perfected the technology. Also, with a full 3.5″ trapway, these toilets virtually never clog. All of Caroma’s toilets are on the list of WaterSense labeled HET’s (High Efficiency toilets) and also qualify for several toilet rebate programs available in the US. Please visit my blog
to learn more or go to to learn where you can find Caroma toilets locally. Visit to see how we flush potatoes with 0.8 gallons of water, meant for liquids only. Best regards, Andrea Paulinelli, owner ecoTransitions Inc.

Adam said...

When we say dual flush, does it really conserve water?. For what reason?. Please enlighten me. Actually these toilets are same with plumber in northern beaches who installed my toilet.