Spin-off

Joulia

The heat you already paid for, going down the drain

Challenge

Showering is one of the largest single uses of energy in a home, and almost all of that energy leaves immediately. Water heated to forty degrees runs across a body for a few seconds and then goes down the drain still warm, carrying its heat into the sewer. Every gram of it was paid for twice - once to heat, once to lose. The heat is not scarce or hard to find. It is simply moving in the wrong direction, three centimetres below the person paying for it.

A shower: the one place in a house where hot water is bought and lost in the same second

Solution

The idea started as an internal Creaholic project in 2007 and became Joulia SA, spun out of Biel in 2010 with Creaholic and private backers. Co-inventor Christoph Rusch is still the company's CTO. The device is a heat exchanger built into the shower drain itself: outgoing warm waste water and incoming cold fresh water run past each other in counterflow, so the cold water arrives at the mixer already preheated and less hot water is needed to reach the same shower temperature. The first product, a shower tray with the exchanger in its floor, launched in 2012; the current generation is a module inside the drain channel, which fits a normal bathroom without redesigning it.

Results

Recovery runs to over 60% of the energy a shower uses - roughly CHF 100–200 a year for a single-family home, typically paying for itself in under five years. More than 10,000 units are installed across Europe. At one development in Urdorf, 39 units save about CHF 8,400 a year and allowed 10% smaller building services, taking CHF 20,000 off construction costs before a single shower was taken. The technology carries Watt d'Or, Solar Impulse and Swiss Excellence recognition and is certified by SVGW, DVGW, KIWA and WRAS.

Ten thousand of these are now in floors across Europe

At a glance

Founded: 2007 as a Creaholic project · spun out as Joulia SA in 2010
Recovery: Over 60% of shower energy, recovered in the drain
Recognition: Watt d'Or · Solar Impulse Efficient Solution · Swiss Excellence
Installed: 10,000+ units across Europe

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