In this work, the topic of airflow dehumidification in HVAC systems is studied. The work compares three dehumidification methods: traditional dehumidification with low-temperature cooling coils, isoenthalpic dehumidification with desiccant wheels and a novel near-isothermal dehumidification operated by heat and mass exchangers coated with desiccant material. Systems performances have been evaluated using as a case study a gym located in Florence, Italy. An hourly simulation throughout the cooling season has been performed. Results indicate that the coated exchanger system achieves a 70% reduction in cooling power requirements compared to the traditional method, while the desiccant wheel system achieves a 41% reduction. Additionally, the COP (Coefficient of Performance) of the refrigeration device is enhanced in both systems assisted by desiccant material. This comparative analysis highlights the potential of advanced dehumidification technologies to significantly improve HVAC system performance, posing them as interesting options to decarbonise the HVAC sector.