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Advisory Notes for the Purchase of Flow Controllers with WELS Labels

Determination of Water Consumption of Existing Water Taps or Showers for Bathing

1. Before choosing flow controllers, consumers are advised to check the water consumption of their existing water taps or showers for bathing. A simple method of checking the water consumption of existing water taps or showers for bathing is suggested in the website of the Water Supplies Department).
   
   For example, if the measured water consumption of your shower is below 9 litres per minute, the water consumption of your shower is already comparable to that of a Grade 1 WELS showers for bathing.
   
   The water efficiency grading of the WELS water taps is:

   Nominal Flow Rate : ƒ (l/min)	Water Efficiency Grade
   ƒ ≦ 5.0	Grade 1
   5.0 < ƒ ≦ 7.0	Grade 2
   7.0 < ƒ ≦ 9.0	Grade 3
   ƒ > 9.0	Grade 4

   The water efficiency grading of the WELS showers for bathing is:

   Nominal Flow Rate : ƒ (l/min)	Water Efficiency Grade
   ƒ ≦ 9.0	Grade 1
   9.0 < ƒ ≦ 12.0	Grade 2
   12.0 < ƒ ≦ 16.0	Grade 3
   ƒ > 16.0	Grade 4

Selection of Suitable Flow Controllers for Water Taps / Showers for Bathing

2. Consumers are recommended to install flow controllers with the nominal flow rates lower than the water consumption of the existing water taps / showers for bathing, the recommended combination are as below:

   Selection of different grades of flow controllers for water taps:

   Water Consumption of Existing Water Taps ƒ (l/min)	Water Efficiency Grade of Flow Controllers for Water Taps
   	Grade 1	Grade 2	Grade 3	Grade 4
   ƒ ≦ 5.0	-	-	-	-
   5.0 < ƒ ≦ 7.0		-	-	-
   7.0 < ƒ ≦ 9.0			-	-
   ƒ > 9.0				-

   Selection of different grades of flow controllers for showers for bathing:

   Water Consumption of Existing Showers for Bathing ƒ (l/min)	Water Efficiency Grade of Flow Controllers for Showers for Bathing
   	Grade 1	Grade 2	Grade 3	Grade 4
   ƒ ≦ 9.0	-	-	-	-
   9.0 < ƒ ≦ 12.0		-	-	-
   12.0 < ƒ ≦ 16.0			-	-
   ƒ > 16.0				-

3. Consumers are advised to check whether their existing water taps or showers for bathing are operating at low flow condition. This condition may be due to the low water pressure in their premises, e.g. a premises situated at the top 3 floors of a building without pressurisation installation. If such condition exists, consumers should choose suitable flow controllers which generally allow larger water flow in low pressure condition. This can avoid affecting the operation of the water heater.
4. The water consumption indicated in the WELS labels is a laboratory test result for grading purpose. This may be different from the actual water consumption level. The actual water consumption depends on different circumstances such as the water pressure in the premises.
5. There are various models of flow controllers which are compatible with different models of water taps and showers for bathing. When choosing flow controllers, attention should be paid to the characteristic of the water taps, such as their sizes and shapes of outlet, or the models of showers for bathing, such as whether they are originally assembled with flow controllers which may not be practicable to install an additional one. Should there be any queries about choosing flow controllers, please contact relevant retail shops or suppliers of flow controllers.
6. Consumers are advised to follow the manufacturer's or importer's instructions in installing the flow controllers to the existing water taps or showers for bathing. If necessary, consumers should make sure that the flow controllers are installed at the correct position and flow direction.
7. The WELS serves to inform consumers of the water consumption level and water efficiency grading. Other additional features for individual flow controllers are not covered by the scheme. Should there be any queries about those additional features, consumers are advised to contact relevant retails shops or suppliers of flow controllers.
8. An un-registered WELS water tap or shower for bathing used with a registered WELS flow controller does not represent as a registered WELS water tap or shower for bathing. Some other performance requirements are necessary to be fulfilled.

Selection of Suitable Flow Controllers for Water Taps / Showers for Bathing with Water Heaters

9. In general, consumers can follow the guidelines below:

   Water Efficiency Grade of Flow Controllers	General Guidelines
   Grade 1	Water-saving and compatible with the storage type water heaters.
   Grade 2	Water-saving and compatible with the storage or flow-controlled type water heaters.
   Grade 3	Minimal water-saving and compatible with most types of water heaters (except electric pressure-controlled type).
   Grade 4	Compatible with all types of water heaters but not water-efficient.

   Generally, the water heaters available in market can be divided into three main types, which are (1) storage type, (2) flow-controlled type (can adjust the water temperature, with or without Hi/Low temperature mode), and (3) pressure-controlled type (can adjust by Hi/Low temperature mode only).

   All the above information is for reference only, there may be different operational results for individual water heater, flow controller, mixing type water tap or shower products due to their different specifications.

10. Storage type electric water heater shall not be connected to any flow controller with shut-off mechanism to prevent excessive pressure from building up in the water tank and thus causing explosion.