March 5-9, 2012, Alta, Norway
On Thursday, Torsten Clupp from Fairbanks in Alaska presented his first-hand experience with designing, building and living in a passive house in the North. This presentation is what I called being passionate about passive houses!
Torsten started his presentation with listing several problems in the Arctic regions, such as learning to live with the arctic sun, full exploitation of free energy from the sun, building sustainable shelters in an unsustainable world evolution and designing buildings for people, and not for buildings. For all these reasons and many others, Torsten has decided to build his own passive house with a floor area of 214 m2 and the heating demand of 14 kWh/(m2.a) in Fairbanks in Alaska(latitude 64°, 14,000 heating degree days and the annual average temperature of -2.8°C).
Torsten´s goal was to build a house according to passive house standards with technologies allowing the building to function without fossil fuels and any conventional heating. The walls are built as a diffusion-open wall system without a typical vapor barrier resulting in U-value of 0.073 W/(m2.K) and total usage of 12 tons of densely-packed cellulose insulation. Use of cellulose insulation results in 66% less embodied energy compared to polyurethane foam. Diffusion-open wall offers drying potential in any direction and it works in combination with very high airtightness of n50 = 0.48 h-1. Primarily south-oriented window shade U-value for glazing of 0.20 W/(m2.K) and high g-value of 0.6 to allow high level of passive gains. The windows with frames over-insulated from the outside are located in 40-50% of wall thickness allowing good air-washing on the interior. All these result in up to 20% of additional gains from the sun. The position of windows also allows creating a warm space from outside the window where the effective thermal shutters are placed. The installation of these shutters with U-value from 0.025 to 0.050 W/(m2.K), reduces energy consumption by 7 kWh/(m2.a). The foundation slab is made from 180 tons of sand functioning as an insulated internal mass for passive and active heat storage (U-value of 0.016W/(m2.K)).
Torsten equipped his house with mechanical ventilation, with supply air coming in via a heat exchanger with preheating in combination with ground loop. The building has an independent system for annual heat storage and there is no backup system. The energy seasonal storage is made with 19,000 liter tank which spread across two levels of the house and there is a water tank in the insulated tank with U-value of 0.014W/(m2.K). For 98 days the supplementary heating from wood stove is used which also covers hot water. Just 10 days after the last fire was lit in the fire place, the house was able to maintain a good environment because of the passive gains through windows, i.e. from mid-February through early November the passive heat gain from the sun keeps the home at 20-22°C without additional heating.
Torsten´s presentation sends a great message about the ability to reach a passive house in such a demanding climate. Torsten finished his presentation with a statement about what a powerful message it would be if Sami Parliament or any other public building would be built to passive house or even zero-energy standards.
Read more about SunRiseHome at www.reina-llc.com.
Photo: SunRiseHome by TorstenClupp