Energy Performance: Is a Higher or Lower SHGC Better?

The National Fenestration Rating Council (NFRC) tests and certifies windows, doors and skylights based on their energy performance. As a result, the NFRC label provides a well-founded means to determine a product’s energy-related properties and to compare them with other similar products.

In this post, exterior renovations expert discusses solar heat gain coefficient, one of the energy performance characteristics of windows, doors, and skylights that can be measured and rated.

What Is the Solar Heat Gain Coefficient?

Simply put, solar heat gain coefficient, commonly known as SHGC, measures how well a window, door, or skylight blocks heat from the sun. The solar radiation admitted through the product can be either transmitted directly and/or absorbed and then subsequently released as heat throughout the house.

Is a Higher or Lower SHGC Rating Better?

SHGC is typically represented by a value between 0 and 1. Generally, a lower SHGC transmits less solar heat and provides greater shading ability. A product with a high SHGC rating, however, is more effective at collecting much-needed solar heat during freezing weather. Meanwhile, a door or window replacement product with a low SHGC rating does a better job at minimizing the home’s overall cooling load in the summer by blocking heat gain from the sun.

What SHGC Rating Should You Opt For?

An SHGC value of 0.42 to 0.63 is ideal. However, various factors determine the desirable SHGC rating for your home. These include the local climate, orientation of the windows, doors, or skylights, and external shading. For example, homes in hotter climates should look for values as low as 0.25. If you cannot decide on a product that will deliver the most benefits, consult a window and door professional.

Protect your home against elements. Hunterdon Roofing, Siding and Window Company assists with window and door installation, roof replacement, trim and millwork, and more for your convenience. To schedule an appointment with one of our professionals, call (908) 503-5393 or fill out our online form.