© Photo | Pilpit

Hot water from exhaust air

An EC fan is at the heart of the heat recovery system made for easy retro­fits by Pamon Ab. But first its alarm relay had to learn “Finnish.”


Many apart­ment build­ings were built in Finland and Sweden between 1975 and 1995. These days, of course, their energy design is no longer up to modern stan­dards, much heat is wasted unused, espe­cially when heating during the cold northern winters. Many owners’ asso­ci­a­tions for older apart­ment build­ings want to achieve a lasting reduc­tion in energy costs. The Finnish company Pamon Ab from Hollola near Lahti, a well-known ski-jumping venue, noticed this trend and devel­oped its Pilpit heat recovery system for exhaust air. It is compact and easily retro­fitted.

Conve­nient savings reports

The warm exhaust air from the kitchens and bath­rooms in an apart­ment complex is usually routed out of the building via a central duct through the roof. Pilpit is simply mounted on this duct. A RadiPac EC fan draws in the exhaust air and a heat recovery unit extracts heat from it.

The extracted heat is then reused for heating and hot water. Timo Viher­vaara, head of sales and marketing at Pamon Ab, says: “This way our customers can save up to 50 percent on annual heating costs, so Pilpit pays for itself in just a few years.” And the customers receive conve­nient reports about the monthly energy savings; the system sends them auto­mat­i­cally by e-mail. “Of course the EC fan’s elec­tricity consump­tion is also accounted for. Through the fan’s Modbus connec­tion, we always have exact infor­ma­tion about this data and can analyze it easily.”

Our customers can save up to 50 percent on annual heating costs, so Pilpit pays for itself in just a few years.

Timo Viher­vaara, head of sales and marketing at Pamon Ab

Full power at peak times

The EC fan is infi­nitely adjustable and its output adapts to daily needs; there is much more usable exhaust air on Monday evenings at 6:00 when every­body comes home and cooks dinner than on Sunday morn­ings at 5:30. “We program the fan so it takes the fluc­tu­ating demand into account. That ensures that the complete system always works with optimum effi­ciency,” says Viher­vaara.

Shining green, not flashing red

And when things aren’t running quite right, the fan speaks the right language. Normally, an error message is sent and a red alarm lamp flashes when a fault occurs in a tech­nical system. But in the Nordic coun­tries, a different logic applies for fault alarms; here they always want to see an “every­thing is OK” signal such as a constantly shining green light.

When it’s not shining, there’s a problem. Viher­vaara says: “We asked ebm-papst how we could deal with this Nordic pecu­liarity. Without further ado, they repro­grammed the alarm relay to green in the RadiPac fans and deliv­ered them to us ready to install. They even gave us the soft­ware in case we decided to change back to red after all.”

Pamon Ab has been using fans from ebm-papst in its venti­la­tion systems for 31 years. “We changed to EC tech­nology in 2009. When we devel­oped Pilpit in coop­er­a­tion with ebm-papst, we focused on the RadiPac,” says Viher­vaara, “because it has an excel­lent design: four screws and it’s in place. And its effi­ciency is a big help in saving our customers so much in energy costs.”

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