How do engineers use their knowledge of air composition?

Engineers utilize their knowledge of air composition to design and optimize various systems, such as HVAC (heating, ventilation, and air conditioning) systems, combustion engines, and environmental control systems. Understanding the proportions of gases like oxygen, nitrogen, and carbon dioxide helps in assessing air quality and performance efficiency. This knowledge also informs decisions in fields like aerospace, where air density affects lift and drag, and in environmental engineering, where it aids in pollution control and mitigation strategies. Ultimately, it ensures safety, efficiency, and sustainability in engineering applications.