Because as an excellent conductor, aluminum draws heat rapidly from your hand to the metal, making your hand feel cooler, though the surface of each is exposed to room temperature. Condensation depends on glass or frame surface temperature, household humidity, and room temperature.
Condensation can occur independently on glass or frames.
Quality installation has a major impact on window performance, including ease of operation and the extent of air leakage. Aluminum's strength, rigidity and light weight make aluminum windows easy to install for maximum performance. Not at all. Some windows barely meet the standard, while others greatly exceed it. Modern aluminum windows are attractive, energy-efficient, and reliable.