Fans, the foundation of mechanical ventilation, account for a significant portion of the energy consumed by HVAC systems. One way to reduce the energy for air transport is to use energy-efficient motors. However, recently, a growing body of information has emerged about the potential of using fan arrays as a good way to optimize operating costs. This article assesses the impact on electrical power demand and acoustic parameters of replacing a single large fan with two or more fans connected in parallel. Additionally, the article considers the impact of airflow and various methods of fan speed control. The conducted analyses led to the conclusion that the number of fans in a system is not crucial. Significant potential for improving energy efficiency when using fan arrays lies in their simultaneous integration with high-efficiency EC motors. However, in a broader context, regardless of the number of fans, the greatest potential lies in limiting airflow whenever conditions allow. Selecting the appropriate fan speed is crucial to ensure that the system pressure does not exceed the minimum pressure at which the required airflow can be achieved. For this work, the selection process was repeated multiple times, which led to the conclusion that it is always worthwhile to repeatedly select a fan or fan array during the design process and only then choose the best solution. This provides the opportunity to reduce electrical power demand by 7% compared to the average electrical power resulting from multiple selections.