Supplyandexhaust

Supplyandexhaust is a term used in ventilation engineering to describe the integrated management of air supply and exhaust within a building or process system. The approach aims to maintain indoor air quality and thermal comfort while minimizing energy use by carefully balancing the amount of fresh air supplied with the air removed.

A typical supplyandexhaust layout includes an air handling unit or rooftop unit that conditions and supplies air, exhaust fans and ductwork to remove air, and control strategies that modulate dampers and fan speeds. Sensors monitor variables such as pressure, CO2, humidity, and temperature to maintain a specified ventilation rate and building pressurization. Energy recovery devices may be used to exchange heat or moisture between supply and exhaust streams, improving efficiency.

Applications include commercial buildings, laboratories, cleanrooms, healthcare facilities, and data centers, where precise control of airflow and pressure is important. Design challenges include avoiding backdrafts, ensuring adequate outdoor air without excessive energy use, and accounting for occupancy patterns, building envelope leakage, and filtration requirements. Good practice involves compliance with standards such as ASHRAE 62.1 for ventilation and ASHRAE 90.1 for energy efficiency, along with local codes.

Maintenance involves regular inspection of filters, dampers, fans, and seals, along with performance verification to ensure the supply and exhaust streams remain balanced. The term supplyandexhaust may be used variably in industry to refer to integrated systems or to separate but coordinated supply and exhaust components within an overall HVAC strategy.