Optiwin Wood Passivhaus Windows

Credit: Optiwin USA LLC

What makes this product green?

  • Reduces heating and cooling loads


German manufacturer Optiwin makes high-performance wood windows, including some certified by the PassivhausA residential building construction standard requiring very low levels of air leakage, very high levels of insulation, and windows with a very low U-factor. Developed in the early 1990s by Bo Adamson and Wolfgang Feist, the standard is now promoted by the Passivhaus Institut in Darmstadt, Germany. To meet the standard, a home must have an infiltration rate no greater than 0.60 AC/H @ 50 pascals, a maximum annual heating energy use of 15 kWh per square meter (4,755 Btu per square foot), a maximum annual cooling energy use of 15 kWh per square meter (1.39 kWh per square foot), and maximum source energy use for all purposes of 120 kWh per square meter (11.1 kWh per square foot). The standard recommends, but does not require, a maximum design heating load of 10 W per square meter and windows with a maximum U-factor of 0.14. The Passivhaus standard was developed for buildings in central and northern Europe; efforts are underway to clarify the best techniques to achieve the standard for buildings in hot climates. Institut to meet Passivhaus standards for airtightness and thermal performance. These triple-glazed windows range in overall U-factorMeasure of the heat conducted through a given product or material—the number of British thermal units (Btus) of heat that move through a square foot of the material in one hour for every 1 degree Fahrenheit difference in temperature across the material (Btu/ft2°F hr). U-factor is the inverse of R-value. from 0.12–0.14 with center-of-glass U-factors ranging from 0.09–0.11. Aluminum claddingMaterials used on the roof and walls to enclose a house, providing protection against weather. is available. The Optiwin 3 Wood window has an inner layer of spruce and fir, a middle layer of cork, and an outer layer of larch. A multi-step profile creates a triple-seal for superior airtightness.

Manufacturer Information

Optiwin USA LLC
301 White St. S.W.
Minneapolis/Watertown, MN 55388
Phone: 651-925-0866

Listed in: Wood Windows