Flow rates for showers are expressed on the water rating label in litres per minute (L/min).
The most water efficient showerheads have a 5 star WELS rating demonstrating a flow rate of 6 litres per minute or less.
The star rating takes into consideration overall performance of the shower in addition to its water consumption.
Showers are tested for:
• angle at which water sprays from the head (to be between 0°and 8°)
• drop in temperature between 150 mm and 750 mm below the shower head (no more than 3°C)
• endurance of the flow controller by being turned on and off around 50,000 times
• spray force and coverage (4 star showers only)
• water consumption