What is the average flush rate for a dual flush toilet with a high flush...

The average flush rate for a dual flush toilet is calculated by weighting the high and low flush rates according to the frequency of use. According to the LEED Reference Guide for Building Design and Construction 1 , the frequency of use for male and female occupants is assumed to be as follows:

Male full flush: 1 time per day

Female full flush: 1 time per day

Male low flush: 2 times per day

Female low flush: 2 times per day

Therefore, the average flush rate for a dual flush toilet with a high flush rate of 1.6 gpf (6 lpf) and a low flush rate of 1.05 gpf (4 lpf) is:

6 ( 1 × 1.6 ) + ( 1 × 1.6 ) + ( 2 × 1.05 ) + ( 2 × 1.05 ) ​ = 1.19 gpf ( 4.5 lpf )