Transparent envelope: energy performances calculation in according to NFRC rating system

Transparent envelope: energy performances calculation in according to NFRC rating system
March 14, 2017 admin

An high performances envelope is the result of a good design that considers, at least, the climatic context of the location of the building, the well-being of the occupants meant as indoor comfort, the daylight and the view. The Thermal Transmittance, the Visible Transmittance, the Solar Heat Gain, the Condensation Resistance factors, define the transparent envelope performances features. In addition, if these values are put into an energy simulation help to evaluate the whole building performance.

Macro Design Studio provides consulting services in the field of sustainability and it is a partner for façades manufacturers and designers for evaluation and analysis according to NFRC (National Fenestration Rating Council Incorporated) standard.

These assessments are made for designs that have to be realized  in the United States, for example, or for minimum performances evaluations as required from LEED® – Leadership in Energy & Environmental Design protocol, on the base of ASHRAE standard.

The National Fenestration Rating Council is a third nonprofit organization, leader in training, that manages an independent rating, energy performance label, for the assessment, the test and certification of glazed systems (

Basically, the glazed systems check is done by the processing model of every section of the window (and the glass surface) through the use of recognized software, such as Therm and Window, which are configured from the Berkeley University (California). These softwares, approved and certified by NFRC, allow the calculations of the Thermal Transmittance (Uw), the Condensation Resistance (CR), the Solar Radiation transmitted from the window (SHGC) and the Visible Transmittance of a glazed system.
The obtained data are compared with the tabulated values, for example, according to the climate area, the intended use and the type of glazed element.

Macro Design Studio is available to manufacturers and designers of façades for energy performances evaluation and verification in accordance with ASHRAE and LEED standards.