When it comes to your home air conditioning and heating units, it may be tempting to take to the internet to cut costs or find ways to maintain air systems on your own. Though there is a wealth of information to be found on the internet, when it comes to your air conditioning, there is one quick fix that you’ll find the internet recommending that you definitely do not want to use.
Given the name, it’s easy to see why such confusion exists. Duct tape, one of the more useful and practical tools in everyone’s toolbox, can be used for a slew of projects, but it should never be used to repair a leaking duct.
As we previously discussed, duct tape had come back from World War II as the returning soldiers’ go-to for just about every home repair. In the battlefield, duct tape had proved an invaluable resource, and it proved just as useful at home. Its popularity only grew when Johnson and Johnson began manufacturing the formerly green tape in shiny gray to match the duct work it was often being used to repair.
Ironically, it is exactly what makes duct tape so useful for just about everything else is the same thing which makes it such a bad choice for repairing duct work. Duct tape is comprised of three components, each adding an element to what duct tape makes duct tape so versatile: it is strong, waterproof, and able to stick to anything. Cotton mesh fabric is what makes duct tape super strong and also easily to tear. Polyethylene is a plastic coating used to coat one side of the fabric, and it is what gives the tape its waterproof coating and extends the overall flexibility of the tape. Third, duct tape is given a unique compound of adhesive materials, including rubber and a thicker glaze of adhesive which makes duct tape tackier than standard tape.
In the late 90s, the Environmental Energy Technologies Division at Lawrence Berkeley National Labs conducted experiments to see which duct sealants would provide the best methods for reducing points energy loss throughout duct systems. For their experiments, they compared duct tape, UL181B tape, foil tape, butyl tape, mastic, and aerosol sealants, then subjected the materials to “baking tests” and “aging tests.”
When it came to the results, the scientists were not too surprised to find that duct tape was an underperformer to say the least. When exposed to forced air systems, duct tape is unable to hold up to either test because its layers became separated during heating and cooling. The exposure was so bad, in fact, that the duct tape could not make it past a week in the aging test. During the baking test, it failed miserably too. As it turns out, prolonged exposure to forced heat literally baked the rubber adhesive compounds in the tape, causing it to harden and, most of the time, simply fall off of duct work repairs.
As it stands, mastic sealants are most commonly recommended for duct and air conditioning repairs, as they are allowed to slowly harden and fully seal the holes and gaps in duct work. No matter your repair, it is always a good idea to consult a professional about air conditioning, heating, and maintenance, especially if you believe that your systems are not operating to their maximum potential. Just be sure to skip the duct tape next time.