In our article Save Water When Flushing Toilet we looked at how cistern displacement devices such as Hippo and Save a Flush can be used to reduce the amount of water used when flushing the toilet. With up to 10 litres of treated drinking water being used in each flush, and way to reduce this wastage and save water has to be a good thing.
Unfortunately these simple devices are not perfect. A cistern displacement device works by reducing the amount of water held by the cistern and therefore available to flush the bowl. Every toilet requires a cistern of a certain size if its bowl is to be completely flushed – a toilet fitted with a 9 litre cistern requires 9 litres of water to fully flush its bowl.
When using a cistern displacement device there are times when it is necessary to double flush (i.e. flush the toilet two or more times) in order to clear the bowl. Obviously this is far from ideal since more rather than less water is used overall.
Interflush is a small patented device which can be fitted to any standard single flushing WC syphon (for use with toilets with front of cistern mounted handle) to convert it so that the volume of water flushed can be controlled. Water only flushes down from the cistern for as long as the toilet handle is held down, therefore when a full flush is required, the handle can be held down until the cistern is fully emptied; when only a little water will be required to clear the toilet bowl, the handle can be pressed for just a short time.
By using less water on most flushes, and avoiding double flushing, the manufacturers claim water savings of 47% are possible. With the average person flushing away 60 litres of water per day, a 47% saving offers considerably water (and money) savings – e.g. for a household flushing 14 times per day it corresponds to around £70 of savings annually or a payback period for Interflush of just 14 weeks.
Installation of Interflush can be undertaken by anyone with basic DIY skills and a few common tools, and it is not even necessary to turn off the water supply when fitting the device. The installation process should take around half an hour.