Save water with our simple delayed action fill valves
We are commonly asked by clients how we can support their sustainability agenda and we do this by optimising water use in the washroom.
One of the simplest ways to do this and little understood is our delay fill Hydroflo inlet valves, fitted as standard in many of our cisterns. It is perhaps the most valuable way of saving water in the washroom as it works every time a flush happens and requires no user input.
First, let’s delve a little deeper into how they work.
Standard fill valves
When you activate the flush plate, button, or lever, water is released from the cistern into the toilet bowl by gravity.
The traditional float valve has a float connected to an arm, which in turn is connected to the flush valve at the cistern’s bottom. When the water level drops, the float goes down, causing the arm to open the water supply and let water flow back into the cistern.
As the cistern refills and the flush valve closes, the water level rises. The float rises with it, gradually closing the water supply until the tank is full and the flow of water stops.
The problem with this action however is, as new water flows through the fill valve during a flush and mixes with the water already exiting through the outlet valve. This means the water that flushes into the toilet bowl takes the new water with it until the cistern is empty and the flush valve closes.
During this cycle, around 0.3-0.5 litres of water is wasted per flush.
Delayed Action Fill Valves
Delayed action fill valves, such as our Hydroflo delay fill inlet valves, only allow the cistern to be refilled once the flush cycle is complete.
It does this by having the float inside its own float chamber reservoir that empties more slowly than the cistern, causing the inlet valve to open only after the outlet valve has closed.
Demonstrative Example of Water Saving
Let’s take an average office building block with 200 people in that office. Each using the toilet 3 times a day, working 210 working days a year.
200 x 3 x 210 x 0.5L = 63,000 litres of water per year.
Performance
Flush performance is not affected as the toilet is rated to perform and it’s preset value (typically 6 of 4L)
BREEAM
While historically BREEAM did recognise delay fill inlet valves and award points for the use thereof, currently BREEAM awards points to effective flush volume of the WC only. Nonetheless, the value of using delay fill inlet valves to be a more sustainable building is indisputable
