A portable, mains electricity (AC-powered) device designed to be integrated within the expiratory limb of a ventilator breathing circuit to remove excess moisture through cooling and condensing, whilst also reheating the dried gases to an appropriate ventilator-compatible temperature. It includes a heat exchanger and may include disposable condensate collection devices (e.g., cartridge, collection bag). It is intended to prevent condensation from forming within the expiratory limb and ventilator (rain-out).