How to Create a Cold Air Return in Duct Work

A forced air heating system works by pulling in cool air, heating it, then forcing it through air ducts to the rooms of the home to heat them with warm air. To balance the air pressure and supply cool air to reheat, a forced air system generally uses cold air returns or air ducts with open vents to pull air from the room. Almost all rooms should have one with the exception of places like the bathroom.

• 1

  Determine the location on the large air return duct leading to the furnace where the cold air return will be attached.

• 2

  Draw a template on the air return duct by placing the duct connector against the metal housing and drawing around its circumference using the marker or pencil.

• 3

  Wearing the leather gloves, punch a small hole in the center of the area you have drawn for your duct connector. Using the tin snips, cut away the opening you have marked for the duct connector. Place the duct connector in the opening to be sure you have made it big enough.

• 4

  Run your flexible duct to the location where your cold air return will be ending. Generally a vent larger than the heat vent, in a low location on an opposite wall from where the heat vents are placed, is where a cold air return is found.

• 5

  Place the duct vent in its location and secure it with the galvanized screws. Attach the flexible duct work and secure to the vent with screws. Place duct hangers along the line of flexible duct and screw in place to be sure it does not move inside the wall and cause bumping or noise problems. Place these every 6 to 8 feet or as needed to secure the duct.

• 6

  Attach the flexible duct to the connector you have already attached to the furnace's main air return. Secure with galvanized screws.