Heat and Moisture Exchanger Sunset 30 mg H2O/L @ 500 mL VT 1.6 cm H2O @ 90 L/min. Captures heat and moisture on expiration and returns it to the patient in inspiration Suitable for spontaneously breathing patients with a tracheostomy tube Efficient heat and moisture exchanger to warm and humidify inspired air, reducing the risk of tube blockage from encrustations, with minimal resistance to flow