When sourcing from a factory, prioritize suction power (measured in Air Watts or Pascals) and motor type. For wall-mounted units, brushless motors are preferred for their longevity and lower noise levels. Ensure the vacuum features a HEPA filtration system to capture 99.97% of particles, which is a critical selling point for indoor air quality. Additionally, verify the effective cleaning radius, including the length of the stretch hose (typically 30-50 feet) to ensure it covers the intended installation area without losing suction.