Holtop HFW-840HA1 Vortex Module-Type Air-Cooled Chilled Water (Heat Pump) Unit The Holtop Vortex Module-Type Air-Cooled Chilled Water (Heat Pump) Unit HFW-840HA1 utilizes advanced modular technology with air as the cooling and heating medium. This integrated central air conditioning equipment serves as both a cooling/heating source and combined unit. It can be paired with fan coil units, cabinet-type air handlers, ceiling-mounted air handling units, and fresh air units to