According to the Swedish Energy Agency, Sweden’s municipalities could save nearly €60,000 daily if they improved the efficiency of their commercial kitchens. Ventilation makes up a big part of a commercial kitchen’s energy use and while it can be reduced through heat recovery from extract air, implementing a heat exchange system in a tough environment where there are large amounts of grease, soot, and smoke and doing so in a cost-efficient way has proven challenging – until now: Swedish Greentech company Enjay has developed a heavy-duty heat exchanger that is designed to withstand the toughest environments, recovering the energy from exhaust air in kitchen ventilation system and returning the energy to the building for multiple usages and with significant cost savings. Or, as Enjay CEO Jesper Wirén says:
“Today, the inherent energy in kitchen exhaust ventilation is considered waste – our technology turns that waste into a new, renewable heat source for your building, saving up to 90% of your restaurant’s ventilation heating costs.”
Wirén continues, “Heavy duty environments need heavy duty solutions. Your standard heat exchange system is not going to cut it in a harsh commercial kitchen or laundry – you need something as tough as your environment.”
Back in the 1990s, Enjay co-founders Jesper Wirén and Nils Lekeberg formed UVtech, which developed a ventilation purification system specifically for commercial kitchens using UV filters. This solution is now more or less standard in most commercial kitchen hoods. In 2006, the two men had sold the company and moved on to other ventures, but despite that, customers kept contacting Wirén and Lekeberg, asking if the filter they had developed could be used to protect traditional heat exchanges.
“Everyone we met said the same thing: we know we waste all this energy into the ambient air because grease is clogging up the technical equipment – can we use your filter to protect traditional heat exchanges?’” explains Jesper Wirén, Co-founder & CEO, Enjay. “We had to tell all those customers ‘No’, since our testing had shown that UV filters – or any filter for that matter – will not remove enough of the grease to keep the heat exchangers clean and enable robust and profitableenergy recovery.”
“Nils and I have been working with restaurant ventilation for 30 years, so we decided it was time to crack this problem,” says Wirén. “To make a long story, where we spent many days in front of a barbecue in a test-rig, short; one day we had a eureka-moment”
”We realized that all the existing standard heat exchangers in the market, had a built-in major problem with polluted air: to optimize energy recovery in general ventilation, standard heat exchangers all utilize the Coanda effect to make sure the air flow streaks towards the energy transferring surfaces. Unfortunately, that means that all pollutants also flow towards those surfaces. This creates a massive problem since, unlike the air, the pollutants tend to get stuck to the surface, and if there is one thing that is catastrophic to a heat exchanger, it is to get a build-up of a coating on the energy transferring surfaces. Our Heureka-moment was that we realized that standard heat exchangers work against the natural forces, and during the test period, we had discovered how to avoid this.”
The Lepido heat exchange system works with the natural forces, thanks to its’ unique internal Particle Repellent Geometry, PRG. Lepido is based on several patent families that allow the heavy-duty recovery battery to recycle energy in challenging environments. The patented solutions keep the coils of the recovery battery operational, minimizing the need for maintenance.