A Simple Shower Warning Device That Turns Red When You’re In There Too Long

We know it’s hard to leave the comfort of a hot shower. But you’re wasting water and running up your energy bill, not to mention that you’re late for work.

Showering can be a wonderful, time-free zone when you’re just with yourself enjoying a cleanse.


But each minute you’re in there is wasting a whole lot of water, and running up energy bills from electric hot water heaters. It’s also easy to lose track of time and find yourself running late to work.

Launched on Kickstarter, Sprav is a smartly designed water meter to address all of these issues. Meant to give easy real-time audio and visual cues about how much water and energy a person has consumed, the device clips onto the pipe behind almost any shower head. It lights up green, yellow, and red to reflect current consumption, and the timing of the lights can be customized via a smartphone app.

Sprav grew out of an extra credit project in an engineering class at Case Western Reserve University two years ago. A student team was tasked with creating a green technology that could reduce home energy and water consumption, and the trio (still at Case Western) has worked ever since to develop and refine the product through different design competitions and business accelerator programs.

The device works by sensing water temperature through the pipe and acoustically monitoring the water flow. Because it uses sound, it does not need to gauge the actual water stream and it starts automatically when the shower turns on. There’s no leaking or mess, like a few other devices that are available that require tools and teflon tape.

Bluetooth connectivity also sends data to a smartphone app so a person can track their aggregate usage over time and set goals. Eventually, says co-founder CJ Valle, the team’s aim is to add Wi-Fi connectivity, too, so it can connect to other home systems. There is an open API right now, so a developer could hack that together if they wanted, he says.

Sprav, which starts at $39, could help people make a dent in their home water and energy bills. At average utility rates, the founders estimate savings of $50 a year for every minute a household member shortens their shower. If everyone in the U.S. cut their average shower time by one minute, the founders say, it would be an equivalent CO2 emission reduction of taking 6 million cars off the road.


So far the team has raised more than $18,000 of its $80,000 goal, and is attracting attention from some big names in the tech world. Valle says that startup investors Michael Arrington (founder of TechCrunch) and Chris Sacca are among the 334 people who have backed the campaign so far.

About the author

Jessica Leber is a staff editor and writer for Fast Company's Co.Exist. Previously, she was a business reporter for MIT’s Technology Review and an environmental reporter at ClimateWire.