Background information
The network, which consists of a total of 105 miles of lines, dates from 1965 and is thus one of the oldest in Sweden.
Several studies have concluded that the best way to overcome problems such as corrosion would be to remove the chambers where the problems and risks are greatest, but due to the high maintenance costs, there is no money for this. "It's a catch-22. The money we would have needed to remove the chambers has been spent on maintaining them", explains Mats.
Since March 2016, the district heating chambers have been protected by dehumidifiers based on hot condensation, which have reduced the amount of moisture in the air and stopped the corrosion process. "The critical limit for corrosion is 60% relative humidity. If you keep the spaces below that, corrosion stops", explains Airwatergreen's Research and Development Manager Fredrik Edström.
What problems did the airwatergreens dehumidifier solve?
Kraftringen and Airwatergreen designed the "Dry Climate" service.
It means that Kraftringen transfers responsibility for the climate in the chambers to Airwatergreen for a fixed monthly fee: "This means we don't have to tie up any capital. We receive an invoice every quarter and Airwatergreen takes care of the rest. In addition to lowering the humidity, Airwatergreen provides us with data on how the chambers are doing, which simplifies maintenance planning", says Mats. He also highlights that those working in the chambers have a better working environment:"We want to offer a safe workplace".