Showerloop lets you take a full shower with just 10 liters of water

© Jamani Caillet /  2018 EPFL

© Jamani Caillet / 2018 EPFL

Summer series. Students' project (2/9) - Thanks to funding from EPFL Cooperation & Development Center, EPFL students will test three prototypes of their new eco-friendly shower at a university campus in Colombia this fall. Once back in Switzerland, they plan to install their device right here at EPFL.


A shower typically uses around 10 liters of water per minute and lasts an average of 10 minutes. That makes it a veritable luxury in places where water is scarce – and that includes some developed countries. Two Bachelor’s students at EPFL decided to address this problem by developing an open-source kit called Showerloop that lets people in arid parts of the world take a full and proper shower.

Their device consists of a closed-loop system where the first 10 liters of water are purified and recirculated throughout the shower, which can consequently last 10, 15, 20, 25 minutes – as long as you want. The students have been awarded a grant for their project and in September will install three Showerloop prototypes at a university campus in Colombia.

10 liters is all you need

The Showerloop needs just 10 liters of water to operate, instead of the 100 liters used on average. When you take a shower with Showerloop, the necessary amount of water comes out of the showerhead, and the dirty, soapy water exits through a drain at the bottom just like in a conventional shower. But the water then goes through three different types of filters to be purified.

The first type is a mesh filter that blocks particles like hair and dust that could plug up the pipes. The second contains sand and activated carbon to remove pollutants. And the third uses ultraviolet light to sterilize the water and kill harmful bacteria and other pathogens. The purified water is then fed back into the showerhead, and the loop begins again. At the end of the shower, the 10 liters of water are discharged into the regular wastewater system.

Swiss materials

The two EPFL Bachelor’s students behind the project – Judith Capron in civil engineering and Jean-André Davy-Guidicelli in environmental engineering – were inspired by a standard open-source eco-friendly shower kit that a Finnish engineer, Jason Selvarajan, presented at the COP 21 Climate Change Conference in Paris in 2015.

Capron and Davy-Guidicelli took Selvarajan’s model and created a version using materials available in Switzerland. They carried out their work at the Student Kreativity and Innovation Laboratory (SKIL), a new facility offered by the School of Architecture, Civil, and Environmental Engineering (ENAC) where students can design and build their own prototypes. Constructing their Showerloop turned out to be more challenging than expected, since neither Capron nor Davy-Guidicelli is a natural-born do-it-yourselfer. But that made them even more proud of the end result.

New version

They also wanted to make a version of the Showerloop that could be used on a larger scale than Selvarajan’s, which requires taking down an existing shower in order to be installed. Rather, they envisioned a system that would require simply adding new parts to an existing shower. So they made the necessary adjustments to Selvarajan’s model with materials they found right here at home.

The students calculate that a Showerloop would pay for itself quickly thanks to cost savings on both electricity (since water would not have to be heated continuously) and water (since consumption would be slashed by 90%). According to their initial rough estimates, installing a Showerloop would cost 1,000 francs and have a payback period of around 11 months, depending on the price of electricity. The system’s filters last 1 to 2 years and cost around 40 francs to replace.

Three prototypes in Colombia

Capron and Davy-Guidicelli have just been awarded a Development Impact Grant created by the Coopertion and Devlopment Center (CODEV) from EPFL to further their research. These grants fund projects that contribute to the United Nations Sustainable Development Goals. And the Showerloop fits that bill – it targets major water consumers like public institutions and hotel chains and could represent an important step towards Goal 6, “Ensure access to water and sanitation for all.”

The students will use the grant money to develop, test, and install three Showerloop prototypes in the sports centers’ locker rooms of Universidad del Valle in Colombia when the school year starts this September. They chose Universidad del Valle because it’s located in a water-poor part of the country, and because their project fits in with a sustainable development program at the university, which is eager to test this kind of shower on its campus.

A journal publication

To carry out the tests in Colombia, Davy-Guidicelli will team up with Marisa Boller, also a Bachelor’s student in environmental engineering at EPFL, rather than with Capron. That’s because Boller and Davy-Guidicelli will already be spending the 2018–2019 school year in the country for their required internship year, where they will work on a water treatment system for a cassava processing plant. In parallel, they will develop a version of the Showerloop suited to the materials available in Colombia and to other local constraints, and perform a complete life-cycle analysis of their device.

Their goal will be to make the Showerloop as attractive as possible from an environmental and financial perspective, and to publish an article illustrating its cost benefits in order to attract interest from businesses and organizations. Selvarajan, the engineer behind the very first Showerloop, fully supports the students and will be following their progress closely.

But the student’s plans for the Showerloop don’t stop there. Once back in Lausanne in September 2019, they intend to draw on the lessons learned in Colombia to roll out their system across the EPFL campus as part of their Master’s studies.

High-definition photos to download
(Copyright: © Jamani Caillet / EPFL 2018)

Contact the students


Author: Sandrine Perroud

Source: EPFL