I just want to make sure this wont hurt anything.

Right before I bought this house, it got a new AC and furnace but they did not replace much of the duct work. This vent is right above the AC unit and is the first vent the cold air passes. It was bleeding cold air into the basement so I covered it.

enter image description here

  • 4
    You probably want at least one vent down there, but yea, probably not there. Also note that duct tape is (ironically) not designed for ducts.
    – DA01
    Commented Jul 5, 2012 at 17:37

2 Answers 2


Whether you tape it or otherwise block it, the effect will be the same and it will not cause any damage to your system; it would be no different than if there was a standard register there that was closed.

The only thing I'll note is that duct tape will eventually dry up and fall off. Ideally you would use foil HVAC tape

(source: homedepot.ca)

Unlike duct tape, this will not dry up and will hold the seal.

  • Thanks. I was planning on getting some foil tape (as long as I got no feed back on this damaging the system) this weekend. But at 103 outside I just grabbed the first thing I saw
    – zk.
    Commented Jul 5, 2012 at 18:53

The vent was most likely put in for the winter months and could be closed for the summer time. The thing to make sure is that you still have enough air flow. Depending on how many other outlets you have for the volume of the blower. If the air flow is cut back it can cause the system to run very inefficient or worse case the A coil in furnace can freeze.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.