If an air blower is replaced by another blower of the same capacity but with a smaller discharge outlet diameter, several changes can be expected in the air handling system. The key effects will revolve around the airflow rate, pressure, and system performance. Here's what could happen:
Increased Pressure: The smaller discharge outlet diameter will create higher resistance to airflow, leading to increased pressure within the system. The blower will have to work harder to push the air through the smaller opening, resulting in an increase in the discharge pressure.
Reduced Airflow Rate: As a consequence of the increased resistance, the airflow rate will be reduced. Even though the blower has the same capacity, the smaller outlet will restrict the flow, resulting in a lower volume of air being delivered.
Increased Energy Consumption: Since the blower has to work harder to overcome the higher resistance and maintain the desired airflow, it will consume more energy. The increased energy consumption may lead to higher operational costs.
Potential Overheating: The increased workload on the blower may also result in higher heat generation. If the blower is not adequately designed to handle this additional stress, it may lead to overheating and potential damage to the blower motor.
Decreased Efficiency: The overall efficiency of the air handling system may decrease due to the increased resistance and reduced airflow. The blower might operate at a less optimal point on its performance curve, resulting in lower efficiency.
Possible Noise Increase: The higher pressure and workload might generate more noise as the blower operates closer to its maximum capacity. This could lead to a louder air handling system.
Reduced Performance of Downstream Components: If the air handling system is designed to handle a specific airflow rate, the reduction in airflow due to the smaller outlet diameter might affect the performance of downstream components like filters, heat exchangers, and air vents.
To mitigate these potential issues, it's essential to ensure that any changes made to the air handling system are carefully calculated and appropriately matched to meet the system's requirements. If the smaller discharge outlet diameter is intended to be used, it may be necessary to adjust other components of the system or select a blower with different specifications to maintain optimal performance. Engaging with an HVAC or mechanical engineering professional can help ensure a proper analysis of the system and make informed decisions regarding blower replacements.