Swegon Air Academy seminar in St.Petersburg, Russia, March 1, 2012
Swegon Air Academy seminar was attended by 187 people and a new record was set! One of the participants traveled over 8,000 km just for the SAA seminar.It just goes to show that the distance is not an obstacle if you want to understand more about designing systems which provide good environmental quality indoors.
Mario Bodem talked about his experience with the renovation of building to levels approaching passive house standards. In the beginning, he tested the audience with two thermography images asking which one of these images displays a poorly insulated house. Few people noticed different temperature scales on the images which gives deceiving results. Lesson learned; always set the same temperature scale in thermography software when comparing two images.
Mario talked greatly about renewable energy sources, such as pellets for heating and hot water supply.He showed a picture of a stove in a residential house and next to the stove was standing a small bottle with very small amount of pellets that is necessary to heat the house for a week.
Another example presented by Mario was renovation of secondary school where the changes were made in the architectural and structural design. In this building, the concrete columns were put inside the building by installing the glazed facade on the outside.
Mario took up the European Union’s EPBD target of achieving nZEB (nearly Zero Energy Buildings) in new production by 2020. Some member states such as Germany have been even more ambitious and set the target date as 2018. These new buildings will be built to a passive house standard with additional renewable energy sources. According to Mario, the energy-plus house can generate three times more energy than it requires, for example using photovoltaics on roofs, and other technologies. The traditional resources are limited and nuclear power is not the answer for Germans. According to Mario, the answer to energy savings is the passive house standard which offers factor 10 energy savings in Germany and there are even greater savings possible in Russia.
One of Mario´s presented projects was a residential house with floor area of 180 m2 located close to St. Petersburg and built with 300 mm of insulation in walls with TGI (Truss Joist I-beam) structural wooden beams. Using these elements the warm side of the wall is not connected to the exterior. Only 2 m3 of pellets is used annually for heating providing temperature of 24°C in living room.
Another project was the renovation of concrete apartment building, with 24 apartments which was built in 1974 with a total floor area 2,000 m2. There was a single oil-based heating system for the entire building and the building had many problems with a leaking roof and mold growth. A couples of years ago, several windows in the building were replaced (to 1.4W/(m2.K))and the owner didn’t want to pay for new windows. This was a challenge for Mario´s team and the solution was to partly cover the thick windows frames with insulation from the outside. Also one layer of bricks under the window sill was replaced by insulation. The old windows were replaced for windows with U-value of 0.75-0.9 W/(m2.K). After fixing the roof structure and replacing damaged insulation with cellulose insulation, the roof got a new additional structure on top of existing structure to change the inward slope to outward. The exhaust ventilation system with heat pump was installed on the roof. The exhaust system is self-regulated and set to a minimum required amount of air (15-25 m3/h) and the windows can be opened if the occupants wish to.. One of the windows in the bathroom was replaced with insulated plastic element and an embedded exhaust system,which leads to the roof via the new insulated facade on the outside with the insulation thickness of 140 mm.
The renovation costs came to €475/m2not including the cost for renovation of balconies. After complete renovation, the heating consumption(now with pellets) is down from116 kWh/(m2.a) to 27 kWh/(m2.a) resulting in 87% savings. Primary energy of the building is now 183 kWh/(m2.a). The finance for renovation was provided by energy-efficient loan from the bank with 20% discount.
The audience was amazed by some of technical solutions individually designed for the renovation of this concrete apartment building. There were many questions for Mario about how to insulate a single skin brick construction and how to turn the balcony into an office. Mario answered that the solution was to use polystyrene insulation and very good windows. Another question was about the allowed leakage through vents in window frame in a passive house. The answer was that during the pressure test it must be ensured that the air tightness of the building is achieved regardless of ventilation strategy you use(for example extract air, heat pump, or supply and extract system).
Photo: Hermitage Museum and Palace Square by John Woollett