How to Replace Old Registers With a New HVAC

Locate and Measure

• 1

  Draw a basic floor plan of the house and go from room to room to identify all registers. Note the location of each one -- in the floor, on the wall or in a ceiling -- so its connection to ductwork can be found easily. Indicate the type of register: rectangular, square or oval.

• 2

  Measure each register opening with a tape measure and record the dimensions. Remove the cover and indicate how the sheet-metal opening is secured, with screws into wall studs or just with a flange set over flooring. Record the size and type of the connection to the duct; vents for sheet-metal ducts usually are rectangular or round for flexible ductwork.

• 3

  Buy replacement covers of the same size, but styled to the use of the room. Use steel, bronze, wood or similar materials for floor vents, matched to the floor covering, in one of many decorative patterns. Get metal covers for wall and ceiling registers, either colored to match the walls or a type that can be painted. Buy replacement metal vents of the same size as the opening, but with the proper connector, round for new flex duct.

Remove and Replace

• 4

  Remove register covers. Lift floor covers out of the opening; remove screws holding wall or ceiling covers with a screwdriver. Take out any screws securing metal vents through flanges or tabs. Go in a basement, crawl space or attic, once covers are removed, to get access to the duct serving the register vent. Disconnet the duct from the vent by pulling off sealing tape and and removing any fastening straps or screws.

• 5

  Pull the old vent out of the inside opening once it's disconnected from the duct; you may have to bend mounting tabs to get it to fit through an opening. Position a new vent in the opening; work from the basement or attic access to push the vent into the opening. Fasten it with screws to wall studs or ceiling joists; vents usually have pre-drilled holes for fasteners.

• 6

  Slide new flex duct over the circular opening of the replacement vent, in a basement, crawl space or attic. Run the flex duct up the connector to the point where the vent begins to spread to form the cover opening. Fasten flex duct with adjustable metal or plastic straps; tighten straps to hold ductwork but do not bend or crimp it. Seal the seam between duct and metal with heat-resistant tape, so no air can escape.

• 7

  Place new covers over all register openings. Push floor covers down into the vent opening; gravity will hold them in place. Attach wall or ceiling covers with screws, through pre-drilled holes in the covers. Force the unit's blower to come on, check for leaks around attachment points and adjust the slats in the register covers to the desired amount of air flow.