Helsinki Apartment Building Showcases
the VILPE S-Series

Known for its distinctive appearance and high-quality apartments, Asunto Oy Helsingin Töölön Oscar is a block of flats situated in the Etu-Töölö district of Helsinki, Finland. Completed in 2009, this 8-storey multiple-entrance building with 64 apartments, three commercial suites and numerous common areas such as stairways, a basement and a guest room. The apartments range in size from 45 to 133 sq. metres, some of them located across two floors. There are 180 separate areas in the building which require ventilation.

The building is composed of prefabricated concrete units, standing seam sheet metal roofing was used on the sloping parts of the roof, and rubber bitumen membrane on the flat parts. The angle of the sloping parts is very steep, making the choice of roofing products and their installation process extremely demanding.

The VILPE S-series in its element

Each apartment in the building has its own system for air intake and exhaust including both heat recovery and cooling functions. The system is based on VILPE E250S roof fans, with heat recovery ventilation units for incoming air installed in the sanitary facilities of the apartments and separate VILPE E190S roof fans connected to cooker hoods in the kitchens. The building’s common areas include individual ventilation units for incoming air in each stairway, exhaust ventilation in these areas and in the basement storage area is accomplished through the use of VILPE E190S and E250S roof fans and the building’s drains are ventilated with VILPE sewer ventilation pipes. VILPE products were delivered directly to the building site from VILPE’s warehouse in Korsholm at the beginning of 2009.

VILPE products were chosen for the building due to their easy installation process as well as their operational features. VILPE S roof fans are designed for installation on horizontal surfaces, they are equipped with single-phase motors and controlled with transformers, or, as in this case, with the step transformer of a heat recovery unit. The VILPE E190S is designed for 125 mm pipes, and a 300 x 300 mm VILPE S installation set is needed for installation. The VILPE E250S is designed for 200 mm ducts and installation requires a 400 x 400 mm installation set.

The Challenges of HVAC Planning

The HVAC planning of the building was the responsibility of LVI-insinööritoimisto Helsingin Kartech Oy, under the direction of its managing director Hannu Kallo. According to Kallo, the slope of the roofs and the large number of ventilation ducts in relation to the installation surface were challenging factors during the HVAC planning process.

‘There were nearly 200 units to be installed on the roof, and it was a real challenge to fit all of the ducts into the installation boxes. Maintenance of the equipment units also had to be assessed during the planning stage. In the end, we adopted a solution in which the roof fans were mounted in rows on top of installation boxes with maintenance platforms between them. To improve safety and usability, we even considered securing the hoods of the roof fans with safety cables so they would not fall during maintenance,’ explains Hannu Kallo.

The cooling compressors for the apartment-specific heat recovery units posed a challenge of their own, as the temperature of the condensate air can rise as high as +60 ºC.

‘There really aren’t any roof fans on the market capable of withstanding such high temperatures. Products suitable for the building were available only in the VILPE range, as the motor manufacturer was the only one able to confirm the heat endurance of their motors,’ Kallo explains.

Töölön Oscar (2009)

  • 8-storey apartment building in Helsinki, Finland
  • Roof coating: Standing seam sheet metal roofing (sloping parts), rubber bitumen membrane (flat parts)
  • VILPE products: Nearly 200 S-series roof fans (E190S, E250S) with installation sets. Drains ventilated with VILPE sewer ventilation pipes
  • Custom solutions: 180 separate areas in the building required ventilation. Each apartment, stairway and basement storage area has its own system for air intake and exhaust. Due to a very steep roof angle, the installation boxes were given custom maintenance platforms.

VILPE® Insight – SK Tuote Oy customer journal 2012, VILPE® Weathered 2015.