A BRITISH invention originally developed to stop bathrooms from flooding and causing water damage but which has now become an essential tool to save waste water and energy in hotels, apartment buildings and homes will make its debut at The Big 5 show this month.

Nova-Flo is a mechanical device that automatically shuts off the water supply to taps when the water level reaches the overflow. It has already earned a long list of satisfied clients such as many prestigious London hotels which have made significant cost savings by fitting Nova-Flo.

“Installing these (Nova-Flo) is an insurance policy. It’s not uncommon for a guest to leave the bathroom running and perhaps take a phone call or watch TV, only to find there is water all over the floor,” comments Ray Pask, director of technical services at The Dorchester Hotel in London.

The benefits extend further by causing less inconvenience and embarrassment to forgetful guests and especially those unfortunate enough to be staying in the rooms situated below a flooding bathroom.

Bathroom floods are a problem not uncommon in the UK because overflow outlets are generally small. However, the rest of the world – where 1½-inch overflows are standard – is not immune to the problem, says a spokesman for About Time Design, the manufacturer of the device.

This apart, the use of high-capacity jet tubs has led to increasing inlet flow rates in order to cut down on fill time, and commonly these high flow rates exceed the capacity of even large overflow outlets to control the depth of water, he points out.

Many casinos resort hotels in the US suffer from floods – some of them quite catastrophic – due to the high flow rates feeding jet tubs. Nova-Flo’s US-approved version, Flowban, has been adopted as a retrofit item by many of them, according to the spokesman.

He points out that while bathroom floor drains are commonly installed in many parts of the world – thus mitigating, or eliminating serious damage outside the bathroom environment – this is not an ideal solution, given the growing focus on water saving. “An unattended running tap that allows water to run either down an overflow or to the floor drain has the potential to waste a huge amount of water, and, in addition, the energy used to heat that water,” the spokesman emphasises.

Many attempts have been made to invent a solution to this age-old problem, but most of them use either electronic sensors to detect the water level and sound an alarm, or they trigger a waste outlet to drain the bath but do not shut off the water, thus increasing wastage. Electronic sensors can also be prone to failure caused by contamination from the bath water.

“Nova-Flo is an incredibly simple device that uses mechanical inputs to shut off the water supply to the taps when an overflow is initiated and the water stays shut off until the taps are manually closed,” he indicates.

Elaborating on how it works, the spokesman says: “The float inside the central chamber rises as the overflow water is temporarily held back in the chamber. Magnets on the side of the float interact through the plastic walls of the water supply inlet ports with magnets attached to a flap valve in the water flow. At rest, the magnets are in attraction, North to South, but as the magnets on the central float move upwards, they change into opposition, North to North, and the flap valve is forced into the water flow, shutting off the supply. As long as the tap is left open, water pressure on the supply side forces the flap to stay closed against the ambient air pressure provided by the open tap.

“A very small amount of bleed water is allowed past the flap valve. This means that when the water level drops below the overflow and the central float reverts to rest, manual closure of the tap allows the pressure to equalise and the flap valve will be drawn back to the open position, thus automatically resetting the device.”

Nova-Flo can be retro-fitted in most applications but ideally it should be specified at the construction stage, he adds.

The device sits behind a bath panel out of sight and requires no maintenance or servicing. The only failure mode can be caused by excessive amounts of bath water additives accumulating in the central chamber. The unit is designed with simple push fit attachments and the provision of an access panels will allow it to be removed for cleaning.

Whilst originally designed for bath overflows, it can also be fitted to many types of hand basins and sinks.

Nova-Flo will be exhibited on Stand 2E64 of The Big 5 Show by About Time Design.