Can the Lowly Stop-valve Sink Your Best Water

Conservation Efforts?

Authors:Paul Woods, D. E. D., RA

Joon Sub Lee, MSCMJiyoung Jung, MSCMShriram Joshi, MSCM

Gunhui Jo, MSCM studentAmarendra Chaugule, MSCM student

Texas A&M UniversityCollege Station, Texas

Study Objective

Determine if the stop-valve has a significant effect on the liters per flush of flush-valve water closets.

Importance

If the stop valve adjustment affects gallons/flush, then this should be part of any building commissioning process.

What is a stop valve?

How can it be adjusted?

Subject Building

Typical Restroom Plans

Sample Selection

16 Automatic flush-valve water closets10 from women’s restrooms6 from men’s restrooms

Experimental Setup

The Data

An observational unit is the water closet, automatic flush valve and stop valve combination.The population of interest is all the automatic flush-valve water closets in Langford Architecture Building A

Variables

stop-valve position measured in quarter of turn increments from the full open positionliters per flush

Number of Observations5 observations per stop valve position per fixtureThe number of valve turns from full open to full closed ranged from 2.75 to 3.25 per fixture

FindingsTable 1.

Maximum and minimum flow

Fixture 1w1 1w3 1w2 1m1 4w2 4m2 4m1 2m2  

% Spec 164% 139% 151% 155% 145% 127% 134% 143%  

Max 9.84 8.34 9.06 9.3 8.68 7.64 8.03 8.59  

Min 4.47 4.5 4.07 3.45 .75 2.37 2.6 3.17  

% Spec 74% 75% 68% 58% 12% 39% 43% 53%  

Findings (cont)                  Avg all

Fixture 2w3 2w2 2w1 2m1 3w4 3w1 3m2 3w3 fixtures

% Spec 169% 129% 83% 113% 150% 143% 151% 146% 145%

Max 10.11 7.74 4.98 6.79 8.99 8.58 9.03 8.75 8.68

Min 4.57 3.83 1.53 3.38 2.91 3.18 3.41 3.61 3.17

% Spec 76% 64% 25% 56% 48% 53% 57% 60% 53%

                   

Findings (cont)WaterCloset-Liters per Flush

0.00

2.00

4.00

6.00

8.00

10.00

12.00

0 1/ 2 1 1- 1/ 2 2 2- 1/ 2 3

Stop Valve Position: Full Open to Full Closed

1Ww11Ww31Ww21Mw14Ww24Mw24Mw12Mw22Ww32Ww22Ww12Mw13Ww43Ww13Mw23Ww3

Conclusions and Recommendations

The conclusion of this study is that the stop-valve position alone could increase or decrease water consumption for flush-valve fixtures in office buildings by 50%. The potential magnitude of this effect requires that rigorous methods be developed to insure that this valve is set properly

Questions?