Building science experts from 50 countries gathered at the Passive House Conference held in Vienna, Austria, in April. During the event organizers built two different mini houses for an ice block competition to show the effectiveness of the rigorous green building program.
One house was built to Passive House specifications, with thick insulation and triple-glazed windows. The other was built using conventional construction techniques and double-glazed windows. A 250 kilo block of ice was placed in each mini house, and conference goers were challenged to vote on the amount of ice that would be left in each structure after six week.
Not surprisingly, because the temperature inside the Passive House was maintained for longer, the ice melted more slowly than the ice inside the less well-insulated house. The block of ice in the regular house melted by May 14, but the ice block in the Passive House took 60% longer to melt. At the end of the competition, 20 kilograms of ice remained, despite the hot summer conditions outside.
"This makes it clear that energy-efficient construction ensures a high level of comfort during both summer and winter months," says Günter Lang, Head of Passivhaus Austria. "Passive House buildings also reduce overheating in the summer, without contributing to climate change."