When should the makeup air system start in relation to the exhaust system?

The makeup air system should start simultaneously with the exhaust system to maintain balanced air pressure within the building. This approach is critical for ensuring that the removal of air by the exhaust system is matched by the introduction of an equal amount of fresh air through the makeup air system. If the makeup air system were to start before the exhaust system, it could create a pressure imbalance, potentially causing unhealthy air quality or improper ventilation. Conversely, if the makeup air system were to start after the exhaust system, the building could experience negative pressure, leading to outside air infiltrating through unintended openings, which could disturb temperature control and air quality. Random intervals would not provide the consistency and balancing needed for optimal HVAC operation and efficiency. Therefore, simultaneous operation is essential for effective ventilation and maintaining indoor air quality.