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 of 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. Greentech company Enjay has developed and connected a heavy-duty heat exchanger that is designed to withstand the toughest environments, recovering the energy from exhaust air in the ventilation system and returning the energy to the building for multiple usages and with significant cost savings.
Back in the 1990s, Enjay co-founders Jesper Wirén and Nils Lekeberg formed Uviteck, a company that 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 put all this energy into the ambient air because grease is clogging up the ventilators – can we use your filter to protect traditional heat exchanges?’” explains Jesper Wirén, Co-founder & CEO, Enjay. “At first we said, ‘Sure, we can do that, no worries’ – we figured we’d reduce the grease, and it wouldn’t be any problem. Except that it was. After a year of testing, it turned out the filter wasn’t any good when it came to energy recovery, because UV filters – or any filter for that matter – will become clogged and the maintenance alone will cost you more than you save on heat exchange. The filter was great for degrading odor and grease, but not great for energy recovery.”
Finally, after five years of saying no to the market, Lekeberg was contacted by a major HVAC consultant in Sweden. There still wasn’t a viable solution, despite customers saying exactly what they needed.
“Nils and I have been working with restaurant ventilation for 30 years, so we decided it was time to crack this problem,” says Wirén. “We began with developing a new filter. We tried one where we were trying to capture the grease by condensation power, where basically, you cool down the air and you attract the grease to the condensation. Turns out it was the worst filter in the world – we didn’t capture anything at all!
“But, because we cooled down the air the coolant was warmed up by the air stream, so we got warm water on the outside. We looked at it and we were like ‘hey, wait a sec – this is exactly what we want. We want to warm up water and at the same time we don’t want the grease to stick’. Basically, we changed our mindset, and it was then we were able to build something that would work.”
The Lepido heat exchange system, is based on two unique patents that utilize a heavy-duty recovery battery to recycle energy in challenging environments. The patents, PRG and APC, keep the coils of the recovery battery operational, minimizing the need for maintenance.