Energy efficiency in Stockholm with modification of the ventilation unit

A large condominium association wanted to improve its energy efficiency. Energy consumption monitoring and reporting was developed as part of the project. In this context, it was observed that it was not possible to monitor and control all ventilation units remotely. The solution to the problem was modification packages, which saved both time and money.

One of Sweden’s largest condominium associations is in Haninge in Stockholm County. Väduren, which includes a total of just over 900 apartments, was built in the 1960s and 70s and consists of both high-rise and low-rise buildings. More than 60 Enervent LTR-7 units are installed in the low-rise buildings belonging to the association. The units were ordered at different times about ten years ago. Each unit serves a stairwell with 4–6 apartments.

In connection with the energy mapping carried out by an external expert, it was observed, among other things, that some of the units manufactured by Enervent were equipped with an older control system, which did not enable remote monitoring.

– There were 25 LTR-7 eco EDW units on site. The units were still fully functional, but remote control was not possible. The remote-control problem was easy to solve, as the units equipped with DC fans were compatible with the newer Enervent eAir remote control system, confirms Jens Krantz, who is sales manager at Enervent Zehnder in Sweden.

– In this case, the modification packages were an effective way to extend the life of the ventilation units. We simply replaced the control system in the ventilation units and now it is easy to monitor energy consumption and service managers can share unit-specific measurement results, for example in the form of an Excel table.

When and how to choose modification packages?

Modification of the ventilation unit is an excellent solution if a ventilation unit installed in a difficult place or integrated in structures needs to be updated. Similarly, if you want to do an eco-deed in connection with the ventilation renovation or if you want a more advanced ventilation control.

Dozens of modification packages are available, and their content depends on the unit model and the customer’s needs. The most comprehensive modification packages include almost the entire technology – only the metal casing and the mechanical parts of the heat exchanger remain from the old unit. The packages installed in Haninge only contained the control system.

If you are interested in updating your own ventilation unit using a modification package, you can contact our technical support, who will find the best solution:

If necessary, Enervent Zehnder’s technical support team even travels abroad to install modification packages, as was the case in Haninge. In Haninge, the installation of the modification packages went quickly as our own professionals, who know the units and technology inside and out, were on site.

– From an installation point of view, this was an easy project for us. The stairwells’ units are in the attic, which was only accessible from the outside through the roof hatches, but even that was not a problem in good weather, says Oscar Husman from the technical support team.

Photo: On the way back, our service car was photographed in central Stockholm

Practice varies somewhat between the Nordic countries. In the object in question, one ventilation unit served an entire stairwell with several apartments. In Finland, for example, there is a regulation that limits the use of rotary heat exchangers in centralized ventilation.