A thermally efficient window saves energy/electricity when the building is acclimatized, whether AC or heating is employed.
Unlike aluminum, rigid modified PVC is an extraordinarily insulating material from which Kömmerling® profiles are manufactured. Besides, the profiles are designed to house double glazing and to allow air-tight windows manufacturing, such as tilt & turn and others. The combination of these factors produces unequalled thermal insulation.
An insulation value of up to 1.81 W/m2°K ** is achieved when employing Kömmerling® systems and special glazing. In the window industry this insulation parameter is known as the U value.
Thinking that double glazing alone achieves good thermal insulation is a relatively generalized conceptual mistake. Although glazing is an important factor, so are the frame and sash material (PVC, aluminum, wood or other) and the operation type's air-tightness.
In the Doors and Windows and Profile Systems sections, you´ll be able to see the most thermally efficient solutions.