How many duct openings are required for a bypass humidifier?

A bypass humidifier is designed to improve indoor air quality by adding moisture to the air, especially during dry seasons. It operates by facilitating air flow through the humidifier while the HVAC system is in operation.

The correct answer indicates that two duct openings are necessary for a bypass humidifier. This setup allows for one duct to draw air from the return side of the system (return air duct) and another duct to send the moistened air back into the supply side (supply air duct). The dual duct design is crucial as it ensures that the humidified air is properly integrated into the heating and cooling system, allowing for effective humidity distribution throughout the living space.

Using only one duct would not be effective, as the humidifier requires a means to draw in the dry air and then return the humidified air to the system. Similarly, having three or four duct openings would complicate the system unnecessarily and could potentially create issues with air flow and pressure. Thus, the two duct openings are essential for optimal performance and efficiency of a bypass humidifier.