Installing Ductwork

Have you ever noticed how there are times when your home simply won't get to the temperature that you want? While you could simply put up with the either excessive heat or the cold, why should you? After all, there is another option available to you. By installing ductwork in your home, you can help to greatly increase the general comfort level in your home. If you are looking at installing some ductwork in your home, then you basically have two choices, hire some one to do the work for you, or to do the work yourself.

While you can always do the work of installing ductwork yourself, it is always best to have a professional do this type of work for you. These professionals typically have the experience necessary to get the job done quickly and correctly. In addition, these professionals usually know the local and state ordinances that cover the installation and maintenance of HVAC units and air ducts. However, if you absolutely feel the need to install your own air ducts, then this is what you need to do. Keep in mind though, that this information is about how to install the ductwork only, not about how to hide exposed ductwork.

1. Determine load calculation. Before you can begin installing any type of ductwork, you need to first determine the load calculation. Basically this means that you need to figure out what the heat loss and gain is for each room in your house. This will help you determine which rooms need the ductwork, and which ones don't. You can find information on how to do this by typing in "How to perform a home load calculation" into your favorite search engine. Follow the instructions that you find, and write down the answers that you get.
2. Draw a diagram. Once you have finished your load calculation, you will need to begin planning your project. This will include drawing out a diagram of your project. Take the time to figure out where you will want the ducts to be, which rooms they will be going into, as well as where the air return ducts will go as well. Draw all of this out on a rough blue print of your home. While your diagram can be rough, try to have it as detailed as possible with the proper measurements of each room included. This will help you determine exactly how much you will need to get for each of your materials.
3. Get your materials. Using the diagram as a guide, purchase enough of your materials so that you can complete the project. Typically you will need to get the following items: flex ducts, registers, return grills, plenum ducts, sheet metal tees and colors (typically a 2 inch minimum for attaching the ducts to the vents, and 4 inch beaded collars for connecting 2 ducts), metal and plastic clamps, metal and plastic clamp fasteners, duct tape, pliers, sheet metal screws (#8), screwdrivers (Philips and regular), scissors and wire cutters, nails and hammer, metal straps or hangers to attach duct work to your basement ceiling, tape measure, safety goggles, work gloves, and a helmet.
4. Cut the holes and build frame. In each of the rooms where you will be placing the vents, you will need to cut holes into the floor. If you are using an HVAC unit, then you will need to cut two holes, one for air return, and the other for the air to go into the room. Be sure that you also cut corresponding holes into the basement ceiling so that you can properly funnel the air. Once you have the holes cut, you need to begin building your frame work for the ductwork. This frame will be what is going to hold the ducts into place as you install them. Attach each of the straps or hangers to the studs or joists in the basement ceiling. As you are attaching the frame to the ceiling, be sure that you are following the diagram that you created earlier.
5. Cut and size ducts. Once you have your framework in place, it is time to begin cutting the ducts themselves to size where necessary. As you get each section completed, set it on the floor near where you will be installing it. This way you will have each of the pieces that you need in place, ready for you to pick up and use. If necessary, be sure that you also cut holes into the plenum ducts to allow air to pass freely through it.
6. Attach plenum duct to HVAC unit. If you are using an HVAC unit, then you will need attach the plenum duct to it. There should be two plenum ducts that you will need to attach, one for the air return, and one for the "exhaust". Place the plenum duct sections into the receiving collars on the fan coils of the HVAC unit, and be sure that there is a snug fit. Flatten the metal tabs against the duct unit, and use the duct pins or clasps and screws to secure everything together.
7. Attach the ducts. Begin to attach the remaining ducts to the plenum ducts. Work on one section at a time, starting with the "exhaust" of the HVAC unit, and then going into each of the various rooms as necessary. Be sure to securely fit each section of ductwork, and then tighten the straps or hangers holding the ductwork in place. Each section should be held in place with straps or hangers that are spaced no more than 5 feet apart.
8. Attach the return air box. Working from your air intake box, and the plenum duct attached to it, repeat the process described in step seven. Once all the ducts have been put into place, cover all the openings you previously cut with their respective grills or covers.
9. Test for circulation and leaks. After everything has been installed it is time to test for proper circulation, leakage, and to see if it actually works. Turn the HVAC unit on, and check to see that you are receiving air flow into all of the rooms that you hooked it up to, as well as if there is any excessive air coming out of the duct work itself. If there is, cover with some duct tape.

Congratulations, you have now completed installing some ductwork in your home. While it may not look particularly pretty at the moment, it will get the work done. All that you need to do now if cover that exposed ductwork.