To deliver comfortable conditioned air by reducing humidity levels while enhancing comfort levels in an air-conditioned space under variable load conditions

an improved design for fully modulating dehumidification with a hot gas reheat system was developed. By managing the charge balance between the cooling and reheat modes

the modulation valve operating range for the reheat mode was expanded. Different microchannel heat exchanger (MCHE) reheat coil patterns were analyzed. The test results showed that an air-cooled unitary unit equipped with this novel MCHE reheat system improved the refrigerant charge balance between the cooling and reheat modes. Under rating conditions

the energy efficiency ratio (EER) in the reheat mode increased by 17%

and water condensate removal through dehumidification was enhanced by 6%. The modulating valve opening range for the reheat mode could be increased from a baseline of 20%–70% to 15%–85%. For the rated reheat dehumidification condition

the modulating range of the reheat temperature rise increased from 8.3–14.4 ℃ to 6.1–19.4 ℃. This innovative solution was proven to achieve a wider operating range that improved dehumidification capacity and achieved energy conservation.