Red Seal Glazier Practice Exam

What indicates outdoor glass failure due to condensation?

1. Visible dirt on the glass surface

2. A sign of seal failure and reduced thermal performance in insulated glass

3. Changes in glass color

4. Increased visibility of the frame

The correct answer is: A sign of seal failure and reduced thermal performance in insulated glass

The presence of condensation on outdoor glass typically signifies a failure of the seal within insulated glass units. Insulated glass is designed with an air gap between two panes, which serves as an insulating barrier to improve thermal performance. When the seal fails, moisture can enter this space, leading to condensation formation. This moisture buildup not only indicates that the seal has failed but also results in a significant reduction in the insulating properties of the glass. Consequently, this not only impacts the energy efficiency of the window but may also lead to fogging, staining, or even mold growth within the insulated space. Recognizing seal failure is crucial for determining the need for repair or replacement of the insulated glass unit, making it essential for glaziers to identify this specific indicator of outdoor glass failure.