The U-value (also known as the thermal transmittance) of an aluminum system design is a measure of how well the system conducts heat. It's calculated by considering the heat transfer through the various components of the system, including the aluminum frame, glazing, and any thermal breaks. Here’s a step-by-step guide to calculating the U-value of an aluminum system:

Step-by-Step Calculation
Determine Component Areas and Properties:

Aluminum Frame: Calculate the area of the aluminum frame (A_frame) and obtain the thermal conductivity (k_frame) of the aluminum material.
Glazing: Calculate the area of the glazing (A_glazing) and obtain the U-value (U_glazing) of the glazing unit.
Thermal Breaks: If thermal breaks are used, obtain their thermal resistance (R_break) and the area they cover (A_break).