A humidifier for an airway pressure support system for delivering a humidified flow of breathing gas to an airway of a patient, the airway pressure support system comprising a patient interface device and a gas flow generator, the gas flow generator being configured to generate the flow of breathing gas to be delivered through the patient interface device to the airway of the patient, the humidifier comprising: a water chamber structured to house a volume of water, the water chamber having an inlet and an outlet; a filter having a housing structured to house a filtration medium therein and having an inlet fluidly connected with the outlet of the water chamber and an outlet; a filtration meter comprising: an inlet fluidly connected to the outlet of the filter, an outlet, a body portion extending between the inlet and the outlet which is structured to convey water from the inlet of the filtration meter to the outlet of the filtration meter, and a mechanism disposed in the body portion which is structured to measure filtration data of the water conveyed through the body portion; a conduit comprising: a first end structured to be fluidly connected to the gas flow generator, an opposite second end structured to be fluidly connected to the patient interface device, and a wall portion defining an interior pathway extending between the first end and the second end, the interior pathway structured to convey the flow of breathing gas between the first end and the second end; a nozzle fluidly connected to the outlet of the filtration meter and configured to produce a water droplet from water received from the water chamber; and a heater plate coupled to the wall portion and exposed to the interior pathway, the heater plate positioned to receive the water droplet from the nozzle. a water chamber structured to house a volume of water, the water chamber having an inlet and an outlet; a filter having a housing structured to house a filtration medium therein and having an inlet fluidly connected with the outlet of the water chamber and an outlet; a filtration meter comprising: an inlet fluidly connected to the outlet of the filter, an outlet, a body portion extending between the inlet and the outlet which is structured to convey water from the inlet of the filtration meter to the outlet of the filtration meter, and a mechanism disposed in the body portion which is structured to measure filtration data of the water conveyed through the body portion; an inlet fluidly connected to the outlet of the filter, an outlet, a body portion extending between the inlet and the outlet which is structured to convey water from the inlet of the filtration meter to the outlet of the filtration meter, and a mechanism disposed in the body portion which is structured to measure filtration data of the water conveyed through the body portion; a conduit comprising: a first end structured to be fluidly connected to the gas flow generator, an opposite second end structured to be fluidly connected to the patient interface device, and a wall portion defining an interior pathway extending between the first end and the second end, the interior pathway structured to convey the flow of breathing gas between the first end and the second end; a first end structured to be fluidly connected to the gas flow generator, an opposite second end structured to be fluidly connected to the patient interface device, and a wall portion defining an interior pathway extending between the first end and the second end, the interior pathway structured to convey the flow of breathing gas between the first end and the second end; a nozzle fluidly connected to the outlet of the filtration meter and configured to produce a water droplet from water received from the water chamber; and a heater plate coupled to the wall portion and exposed to the interior pathway, the heater plate positioned to receive the water droplet from the nozzle.