CASE STUDY

Guard Dog Valve Case Summary

Case Study:

Objective

Identify water loss from the cold water riser lines serving bathrooms in a hi-rise apartment building in Toronto and measure the impact of flow control devices (Guard Dog Valve) being installed on toilets that are supplied by water from these riser lines.

The cold water risers are equipped with Keyence Ultrasonic sensors that measure volume and flow rate.

The sensors are affixed to the cold water branch lines as they come off the header on the top floor. The risers lines subsequently pass through the wall and then run vertically supporting delivery of cold water to bathrooms from the top floor to the ground floor. The lines include single(s) where they serve one bathroom / floor and double lines where they serve two bathrooms per floor.

The sensors measure volume as expressed in L (litres) per day and they measure flow rate expressed in L / min.

This property underwent a full insuite water retrofit program in March 2022. At that time Guard Dog Valves were installed in approximately 150 units on specific riser lines. Subsequently (September 2022), the five (5) riser lines that did not have the valves previously installed on the toilets were part of a project to complete the valve installations.

The installation involves:

1. shutting off water, draining tank and detaching existing supply line from shut off valve to the toilet;

2. connecting shut off valve to the bottom (inlet) of the Guard Dog Valve with standard ⅜” braided flex line;

3. connecting top to the valve to the bottom of the tank with a 20”  ⅜” WC flex line

The valve operates using a motion sensor that detects the presence of a resident in the bathroom.  Once the sensors detects motion, it opens the valve to allow water flow to the toilet. The valves are currently pre-set to remain open for six (6) minutes. At the expiry of the six (6) minute cycle, the valve closes and water no longer flows to the toilet.

By limiting the interval of time during which water flows to the toilet, the loss of water arising from a faulty fill valve and/or an open flapper or failing flush seal (as found in Water Matrix Proficiency toilets) is drastically reduced. There are 1440 minutes in a day. Assuming the motion sensor detects motion in the bathroom 4 to 5 times a day, the window during which water will flow to the toilet is reduced to 24 to 30 mins over a possible 1440 minutes.

TOTAL CONSUMPTION AND LOSS RATE:

The loss rate for the building for the September 15th – September 26th period was 8% as illustrated below:

Sept 27th – Oct 15th 2022

Line 5              2,886 m3 / day
Line 6/8          9.018 m3 / day
Line 10            9.103 m3 / day
Line 11             4.091 m3 / day
Line 16/18 14.826m3 / day

Summary Before / After Daily Average Volumes

Average Daily Change :     11.5 m3 / Day
Average Daily Savings:      $49.00
Annualized Savings:          $17,781
Project Cost:                      $22,400
Payback:                            1.26 

Project Cost based upon $200  (MSRP Valve + Installation)

POST INSTALL : LOSS RATE DROPPED FROM 8% TO 0% (SOURCE:  ALERT LABS FLOWIE O)

Individual Flow Rate:   Line 16 / 18   October  1st – 2nd

Individual Flow Rate  Line 16 / 18  October 15th

• Minimum Flow Rate improved to 0 L / min vs 5 L / min implying period of no flow (overnight)

• Average Flow Rate improved from 21.1 L / min to 8.9 L / min

Addenda:

(1)   SAMPLE INSTALLATION WITH VALVE OUTLET AFFIXED DIRECT TO TOILET TANK

(2)    INTERIOR VIEW VALVE

(3) INSTALLATION GUIDE

For further information, please contact:
Bob Langlois
bob.langlois@water-controls.com
Direct:  416-625-7801