How to Use a PVC Pipe for Ductwork

PVC can be used for ductwork, although it rarely is. Most laboratories use PVC piping, because it is a safer material than metal. Generally, PVC is used only for exhaust systems. PVC can cause some problems with dust and heat exposure. Therefore it should not be hooked up directly to the heating system boiler. It should be hooked up via a flex duct. If done correctly, PVC can be used in a home but it should not be the first option.

Things You'll Need

• Metal strapping
• Brackets
• Coupling sections
• PVC pipe adhesive or cement
• Corner joints

Instructions

1. Measure the ductwork layout as you would for any other duct installation project. Trace the route of the installation and make accurate measurements with a tape measure, recording the number of feet for each length, then translating that into the number of joints and sections you will need for PVC pipe.

2. Lay the PVC pipe section into the duct area. Brace the PVC pipe with metal bracketing. Loop two sections of stranded metal stripping around the PVC pipe and connect the ends to the joist boards with screws. The duct should be supported off the floor. Place one support every three feet.

3. Install coupling sections. At the connection to another PVC joint, install a coupling section that is about a foot long and a little larger than the piping you installed. First, brace the PVC duct with the metal strapping as explained above. Then coat the pipe with adhesive, slide on the coupling section, paint the other end of the PVC duct pipe with adhesive, and slide this into the coupling section.

4. Join the corners. To join a corner of PVC duct work, paint the inside of a PVC corner joint with PVC joint adhesive. Slide the corner onto the PVC duct. Paint the inside of the other side of the joint, and then slide the next section of PVC into the joint. Brace the section as needed using metal bracing, PVC bracing or metal strapping.

5. Connect the PVC duct work to the heating system using flex duct of a similar size. Attach the flex duct around the PVC piping and seal with PVC tape. Make sure there is several feet of flex duct between the PVC pipe and heater.

Tips & Warnings

• PVC is not traditionally used in homes or industrial buildings as duct material.

References

• Industrial PVC ducts

Resources

• PVC couplings
• PVC air duct measurements
• PVC fittings