THERMAL DESIGN

In addition to being a key design element in your home, a window must also serve a variety of functional roles. Beyond providing light and ventilation, a critical function—especially in more extreme climates—windows must contain a thermal barrier between inside and outside.

In the ideal case, a window should provide an even temperature gradient across the entire cross-section of a window. In other words, the transition from outside to inside temperature should be gradual and uniform. Any drastic temperature changes indicate less-than-optimal thermal design. Similarly, lines of equal temperature—called “isotherms”—should be evenly spaced through the cross-section of the window.

As the following plot illustrates, Loewen’s approach to thermal design is significantly different than some other vendors. Several vendors have designs that result in non-planer isotherms, resulting in hot or cold spots on the surface of the window itself. This often happens near where the sash meets either the frame or the glass.

If you look at the Loewen plot, you will see isotherms that are both much more parallel, and more evenly spaced. The result is a more even temperature distribution over the inside surface of the window which is closer to room temperature – whether it is hot or cold outside. This indicates fewer hot/cold spots and results in greater comfort levels for the homeowner. It also reduces energy costs.

Superior thermal performance is a result of several distinct design features unique to Loewen. The cladding design on Loewen clad products deliberately keeps exterior metal away from the interior of the window, and results in increased thermal performance, and a more comfortable environment.