What criterion determines the ideal installation location for a cold air return?

The ideal installation location for a cold air return is low to the ground in an open area of the wall because this promotes effective airflow within the HVAC system. Cold air is denser than warm air, so when a return vent is placed near the floor, it can efficiently pull the cooler air that has settled at the bottom of the room back into the system for reconditioning.

By positioning the return vent in an open area, unobstructed airflow is ensured, allowing for a more balanced distribution of air throughout the space. This setup not only helps in maintaining consistent temperatures but also enhances the overall efficiency of the heating and cooling system. The location provides the best opportunity for the air to circulate, leading to improved comfort and energy efficiency in the environment.