DIY Duct Work

Installing Ductwork

• If you are installing or replacing your ductwork, first determine how many materials you'll need. If you are starting from scratch, measure the linear footage and estimate how many lengths of ductwork you'll need. If you are replacing ductwork, judge the amount of material you will need based on the previous installation. Always purchase more material than you actually need in case you make a cutting or measurement error. Also develop a rough sketch of the layout of your ductwork to help determine how many elbows and other fittings you will need.

  The size of your furnace and the size of the rooms you are attempting to heat and cool will determine the size of your vents and ductwork; also, the length the ductwork must run from the furnace to the vent. If the air has a long way to travel from the furnace to the ductwork, consider insulating the ductwork.

Cleaning Ductwork

• Ductwork accumulates dust and mold over time, creating potential health hazards and system inefficiencies. Regular visual inspections of your ductwork can prevent mold. Look for any leaks or broken seals and check for excess condensation. If you spot any leakage that is not too excessive, you can usually repair it fairly easily. Apply fiberglass tape over the leaking joint and apply a layer of mastic putty over the top of the tape. Although it may seem counterintuitive, do not use duct tape for sealing joint leaks as it does not last as long and is not equipped to repair such leaks.

  To improve indoor air quality and system efficiency, consider having your ductwork cleaned, especially if you purchased an older home with an older HVAC system. Remove one of the joints in your ductwork to perform a visual inspection of the inside and determine if the system needs cleaning. If the ductwork appears to contain a minimal amount of dust or debris, rent a duct-cleaning vacuum to power out any basic contaminants. Seek a professional if you find mold growth, excessive amounts of debris and rodent or insect infestations.