Installed a combination recessed light and bathroom exhaust fan (bath can) on a new 15-amp dedicated circuit. Fan rated at 80 CFM and 1.0 sones for quiet operation. Routed 4-inch insulated duct through attic and terminated with a weatherproof vent hood on the exterior wall. Verified proper airflow and sealed all duct connections. NEC requires all bathroom fans to vent directly to the outside—never into attic spaces—to prevent moisture buildup and mold.