What is the usual recirculation rate (RR) for most DX systems?

The usual recirculation rate (RR) for most direct expansion (DX) systems is indeed 1:1. This means that for every unit of air that is conditioned and discharged from the system, an equal amount of air is recirculated back into the system. This balance is essential to maintain efficiency and proper airflow within the system. A 1:1 ratio allows for effective temperature regulation and humidity control, which is crucial for maintaining comfort and energy efficiency in HVAC applications.

Other recirculation rates, such as 2:1, 4:1, and 20:1, would imply different operational dynamics. Such ratios could suggest a significant increase in the amount of return air compared to supply air or vice versa, which may not only alter how effectively the system conditions the air but could also complicate airflow patterns, reduce system efficiency, and lead to uneven temperature distribution. Therefore, sticking with a 1:1 ratio is the most standard and effective approach for the majority of DX systems to function optimally.