Abstract: An improved ventilator apparatus and method includes a ventilator having an inspiration side for delivery of air to a patient and an expiration side for receiving air from the patient, the expiration side including an air flow path through the ventilator for monitoring of the expired air, a first conduit connecting the inspiration side of the ventilator to the patient, a second conduit communicating expiration air from the patient to an air cooler, and a third conduit coupling the outlet of the air cooler to the air flow path on the expiration side of the ventilator, the air cooler operating to cool the expired air to a temperature sufficiently low as to eliminate moisture condensation as the expired air passes through the flow path on the expiration side of the ventilator. The expired air is preferably cooled to about or below the temperature within the expiration side flow path.