How to Replace and Insulate Furnace Ductwork

What You'll Need
Replacement ducts
Strong gloves and face mask
Wrenches and screwdrivers
Flashlight or headlamp
Utility knife
Plastic ties
Duct tape

Furnace ductwork helps to connect the central air conditioning and furnace systems in your home with the various vents and radiators. These ducts are not only crucial to the proper functioning of the furnace, but they are also very difficult to maintain.

The ducts are typically located in small, cramped parts of the house. They are surrounded by fiberglass insulation that can be damaging both to your skin and to your lungs. Follow these steps and use caution while replacing your furnace ductwork.

Step 1 - Place Ducts Around the Home

Because it can be difficult to get in and out of the area in which your ducts are located, it's a good idea to lay out spare replacement ducts in appropriate areas throughout your home before you begin. This will allow you to continue your project with minimal trips between your basement, attic, crawlspace, or other areas.

Step 2 - Access and Disassemble Ducts

Find a good place to begin your project. The location should be easily accessible and have plenty of light. You may need to use a flashlight or headlamp for some parts of the project. Access the ducts and remove the insulation from around them. Do this very carefully, and be sure to wear heavy protective gloves, a face mask, and any other protective equipment which may be helpful. Examine the ducts to find their connecting points. They are typically held together with screws or bolts. Remove them and put the pieces in a safe place so that they can be used later.

Step 3 - Replace the Duct Pieces One at a Time

Next, replace the duct pieces one at a time. Begin from a central point and replace pieces outward from there. Be sure that you follow all instructions from the duct manufacturer to ensure that the duct is connected properly. You'll need to not only ensure that the duct pieces are connected via either bolts or screws, but also that they are wrapped in duct tape to for greater insulation. If the ducts will not hold up properly, use plastic duct ties to attach them to the roof above.When you reach the register boot or other areas in which the ducts will need to connect to central lines, follow the manufacturer's instructions for installing them. Be sure to wrap the joints in duct tape as well.

Step 4 - Replace the Insulation

After you've replaced the ductwork throughout all or a part of your home, continue by refilling the areas around the ducts with insulation as needed. Again, work carefully to avoid injury. Pack the ducts well with insulation. Doing so will keep electricity costs down, as it ensures that the furnace can function at its optimal level.