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 Construction1, 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)