A bypass humidifier is connected between which parts?

A bypass humidifier is connected between which parts?

• A. Between the discharge side of the furnace and the return side
• B. Between the supply side of the furnace and the return side
• C. In the supply duct
• D. In the plenum

Answer: (B)

A bypass humidifier adds moisture by routing a portion of the air from the supply side through a moistened panel and then back into the return side, so it re-enters the furnace to be circulated again. This is done by connecting a duct from the supply plenum to the humidifier and another from the humidifier back into the return plenum. In this arrangement the humidified air stays in the normal air loop of the furnace, providing humidity to the space without pulling in outdoor air. If the unit were placed only in the supply duct or somewhere else not in the supply-to-return loop, it wouldn’t effectively add moisture to the air that cycles through the house.

A bypass humidifier adds moisture by routing a portion of the air from the supply side through a moistened panel and then back into the return side, so it re-enters the furnace to be circulated again. This is done by connecting a duct from the supply plenum to the humidifier and another from the humidifier back into the return plenum. In this arrangement the humidified air stays in the normal air loop of the furnace, providing humidity to the space without pulling in outdoor air. If the unit were placed only in the supply duct or somewhere else not in the supply-to-return loop, it wouldn’t effectively add moisture to the air that cycles through the house.