It takes more than just energy efficient glass to build an energy efficient window or patio door. The glass is important as it fills the majority of the opening.
We begin with Cardinal Low E glass manufactured in Washington state. The glass units are finished using Super Spacer, a low conductivity flexible organic warm edge spacer bar. Super Spacer, unlike metal bars, optimizes energy savings. Another benefit is lower sound transmittance, and we add argon gas to slow convection inside the sealed unit.
We don't stop there. In our sliding windows and patio doors we use tri-fin weather stripping offering up to 25% improvement in air infiltration over a single fin design.