Dual-Flush Toilets
Dual flush toilets employ a system that has two buttons for
flushing, a full flush and half-flush. The full flush is 1.6
gallons (6 litres) and the half flush is 0.8 gallons (3 litres).
The average flush of
1 gallon (3.8 litres) achieves a substantial savings in water
use compared to the older 3.5 gallon or newer 1.6 gallon single
flush systems. See below for a typical office with 50 occupants
for the potential savings in water consumption and cost.
| No. of toilets |
No. of occupants |
Water use reduction/day |
Water use reduction/year |
Annual cost savings |
| 1 |
50 |
1 cubic meter |
257 cubic meters |
$257 |
In retrofit applications, the replacement of a toilet with a
dual flush model can be paid back in 4-6 years.
For a detailed worksheet for the above table, please contact Prism Engineering.
