A related question is here about a year ago: Is there any reason to not tape this vent over?

My question is, why do they put the vent there in the first place. Like the previous poster, I just bought a house and the A/C duct has a vent right above the A/C unit, cooling down a utility room that contains a sump pump and nothing else at this point. The rest of the basement is finished, but the utility room is closed off by a door.

It seems like there is no problem in taping that up but I am curious what was the logic of having it in there in the first place.

1 Answer 1


There are plenty of reason why, not sure exactly why your is though. Here a few reasons:

  1. Humidity. Circulating air, especially climate control air, will help eliminate differences in humidity that can lead toward mildew, mold, bugs issues, etc.

  2. Selling point. In most regions that I've observed, any climate controlled area can count toward square feet/meters so the house can be advertised at a slightly higher number than is actual livable space.

  3. Climate control balancing. The best thermal boundary is one that is not needed and you do not want a hot/cold spot near the utility room. If the vent is setup correctly for that size room and you are not maxing out your air handler already it is typically more efficient to have a vent open in all interior rooms/spaces. Rooms/spaces with any outside walls depend on the insulation they have but are typically not beneficial, in a properly insulated basement I'm considering any space interior.

  • Thanks. The next question is then, is it worth closing the vents all around the basement. There seems to be controversy regarding this on the interwebs. It might be too much of a case specific question for this site. Jun 26, 2013 at 13:01
  • If you have a sump pump, internal french draining, or any other water that is in the basement then I'd recommend air flow by some means. Otherwise it's more of a personal preference to how often you use it.
    – Jason
    Jun 26, 2013 at 15:47

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