Graham Architectural Products’ GThurm windows featuring glass reinforced polyurethane lineals are the first US-made architecturally rated (AW) windows to achieve thermal transmission measurements as low as U 0.18 (R 5.5) using readily available insulating glass.

GThurm window lineals are pultruded using 80% continuous strand glass fibre and 20% polyurethane resin – the resin was supplied by Bayer MaterialScience LLC.

The first commercial installation of the GThurm windows took place in late 2010 at the Bayer CropScience LP Clayton, North Carolina, Development and Training Facility. A total of 76 windows were replaced at the 50 year old building.

The new windows reduce drafts and will reduce energy loss.

“I could actually feel a breeze on a windy day when I stood next to the old windows,” says John Rock, site manager at Clayton during the installation. “The new windows have greatly increased the comfort of the people who work in this facility. Furthermore, we expect to realise energy savings of roughly 12%, which is significant.”

GThurm windows with pultruded polyurethane lineals are also reported to offer improved dimensional stability, durability, thermal insulation and environmental friendliness over traditional windows.

Graham Architectural Products is part of Bayer MaterialScience LLC’s EcoCommercial Building (ECB) network, an initiative that promotes sustainable building design and construction.