Passive Home Design ( Solar Thermal Magazine) According to Aurimas Sabulis, managing director of Intus Windows, a worldwide leader in top-of-the-line passive house certified products, people sometimes confuse the Passive House Institute of the United States (PHIUS) and the Passivhaus Institut (PHI) of Germany. Sabulis says that they are actually two separate organizations, but they share the common goal of constructing and designing energy-efficient structures
“Dr. Wolfgang Feist developed the Passivhaus standard and the first Passivhaus was built in 1990, in Darmstadt, Germany,” says Sabulis. “Katrin Klingenberg is the co-founder and executive director of PHIUS, an organization she founding in 2007 with Mike Kernagis.”
According to Sabulis, both organizations have rigorous standards for achieving certification, which is voluntary. The standards involve designing and building an energy efficient home with a design that reduces its carbon footprint, by requiring very little energy to heat or cool the home or building.
“The North American climate is very diverse and ranges from extreme desert climates, humid tropical climates, to arctic climates, and everything in between,” he explains.
Therefore, different techniques and approaches are necessary for each distinct climate zone in North America.
Sabulis says that, generally speaking, the Passive House standard for certification includes the following:
- Buildings must be super insulated and air-tight
- Window glazing U-Value of 0.14 or better is preferred (depends on climate zones and other variables)
- Thermal bridges must be minimized or eliminated
- A blower door test must achieve a standard of 0.60 ACH @ 50Pa or lower
- Mechanical air ventilation via an ERV or HRV unit
- Minimal Energy use with a maximum of 4,750 Btu/ft² per year for heating & cooling
- No open flue fireplaces are allowed
- Utilization of passive heat gains from solar, occupants and appliances.
“While this is a pretty complete general summary of the standards, contacting either PHI or PHIUS will provide more detailed specifications,” he explains.
With either organization, one of the most important factor will be determining window glazing options, since that is how the passive solar heat gain is achieved within the structure.