Modern HVAC control systems lack any sort of a link between the temperature sensors and thermal fields inside closed environments. Whether it is the CRAHBP or a single-unit HVAC system, temperature sensors are coupled with the return air temperature. This connection causes HVAC systems to continue operating until the return air temperature falls below a value defined by an operator. It results in wastage of electricity, because a significant amount of electricity is used to cool down almost the entire closed environment. With rapid advancements in cloud computing services, the expansion of existing and establishment of new datacenters is expected to grow. A major portion of the total electricity consumption in datacenters is consumed by the HVAC equipment. In this work, through high fidelity numerical simulations, we show that a coupling between HVAC sensors and the temperature field in regions of interest inside datacenters can lead to substantial saving of energy. For this study, we consider a tier-2, localized datacenter. It should be noted that the implementation of the proposed flow control method presented in this research work will result in improvement of the overall efficiency of the HVAC system without any major changes to already existing infrastructures of datacenters. Our CFD simulations predict that implementing the proposed control method reduces the power consumption of cooling equipment in the datacenter by 23%.