© 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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