Alpen Windows’ unique framing and super-insulating glass system incorporates a combination of key technologies and best manufacturing practices to deliver high performance. Our super-insulating windows are built with highly insulating fiberglass frames, and spectrally selective Low-E coatings, inert insulating gases and warm edge technology that control temperature gains or losses.

Glass is naturally considered to have a high-emissivity characteristic. To better understand this, think of your morning coffee cup, when you pour hot coffee into a glass cup you can easily feel the heat transfer from the coffee to the coffee mug. This example applies to the glazing in your home’s windows as well; in the winter your home’s interior heat is transferred outdoors due to the high-emissivity of your window’s glass. A similar effect happens in the summer but in reverse, the glass transfers heat from the warm outdoors into your cool home.

What are Low-E Coatings?

Low-emissivity (Low-E) coatings were created to counteract the natural high-emissivity of the characteristics of glass. In essence, Low-E coatings act as a thermos would for your coffee cup; it helps control where to keep the heat, either indoors in the winter or outdoors in the summer.

Low-E coatings are thin invisible layers that are applied to the glass or suspended film of an energy efficient window. The coating works by reflecting back heat to its source; in the winter the heat is reflected back into the house and in the summer the sun’s excess heat is reflected back outside. Low-E coatings are unique in the fact that they can block long-wave infrared heat and UV rays without preventing visible light from passing through.

Alpen Windows low-E coatings reflect excess solar heat back outside in the summer and block harmful UV rays

Alpen Windows low-E coatings allow passive solar heat into your home in the winter while blocking harmful UV rays

There are several types of Low-E coatings that benefit each climate differently. In cold climates like Boston, a home can save more energy if it uses super-insulating windows that maximize solar heat gain in the day and minimize heat loss at night. In hot climates, like Phoenix, the reverse would be true.

Alpen HPP understands that one of the best ways to save energy in your home is by utilizing the appropriate low-E coating and thermal performance for your individual climate and your home’s unique orientation towards the sun. Our super-insulating glass packages are carefully engineered to provide optimal performance for a variety of climate zones, so that both energy savings and comfort can be achieved.