Shgc and value relationship

Windows for High-performance Commercial Buildings

Relationship between U value (inverse of R value) and SHGC (g) comparing current low e coatings (dotted area) and required new technology products. U-VALUE & SHGC EXPLAINED. Shgc. When selecting aluminium windows and aluminium doors for your home or building project you will. November 15, - A breakdown of the meaning of SHGC, U-Value, and The SHGC and U-ratings share an interesting relationship in that they share a.

Not all modern windows are the same: Some are energy efficient while others were designed with lower costs in mind. U-factor, or U-value, is a term that's given when estimating the heat loss of a window. Windows with lower values provide greater insulation and heat resistance, helping to keep the interior at the proper temperature and to reduce overall energy costs.

Your Window’s U-Value and SHGC Rating Explained

Some double-pane and triple-pane windows have a U-factor as low as 0. SHGC is short for solar heat gain coefficient, a number that represents the amount of solar radiation through a window. It's measured between 0 and 1; a lower number means less solar heat transfer.

In the winter, solar radiation provides free heat for the home. However, it leads to overheating during the summer months and higher energy bills as you continually adjust the thermostat.

  • Solar gain
  • U-Factor and SHGC: How They Impact Your Windows

Older windows lack these energy-efficient measures. Though the SHGC is more realistic than the SC, both are only rough approximations when they include complex elements such as shading devices, which offer more precise control over when fenestration is shaded from solar gain than glass treatments.

In these components heat transfer is entirely due to absorptance, conduction, and re-radiation since all transmittance is blocked in opaque materials. The primary metric in opaque components is the Solar Reflectance Index which accounts for both solar reflectance albedo and emittance of a surface.

Passive solar building design Solar gain can have both positive or negative effects depending on the climate.

Windows for High-performance Commercial Buildings

In the context of passive solar building design, the aim of the designer is normally to maximize solar gain within the building in the winter to reduce space heating demandand to control it in summer to minimize cooling requirements. Thermal mass may be used to even out the fluctuations during the day, and to some extent between days. Control of Solar Gain[ edit ] Uncontrolled solar gain is undesirable in hot climates due to its potential for overheating a space.

To minimize this and reduce cooling loads, several technologies exist for solar gain reduction.

U-Factor and SHGC: How They Impact Your Windows - hunterdon - Hunterdon Siding & Window Blog

SHGC is influenced by the color or tint of glass and its degree of reflectivity. Reflectivity can be modified through the application of reflective metal oxides to the surface of the glass. Low-emissivity coating is another more recently developed option that offers greater specificity in the wavelengths reflected and re-emitted.

This allows glass to block mainly short-wave infrared radiation without greatly reducing visible transmittance.