Can you hurt ac system by closing vents in rooms you don't need to cool?

[ejchase]

My SO and I are debating this. When his two teenagers aren't spending the weekend with us, he wants to close the vents in their bedrooms since they're not being used. But I've heard people say that can hurt an ac system.

I was thinking maybe those of you here who live so frugally might have done this in the past. Anybody have any experiences with this?

[CathyA]

Its my understanding that you can do that, and it will just go to the other rooms more. But....if they have a return vent in their rooms, I don't know if that presents a problem.

[jania]

I've done this for years, including closing the doors, with no ill effects.

[Glo]

We also have done this for years with no ill effects.

[Never Again]

Closing off vents reduces the system airflow. Closing off too many vents will reduce the airflow too much and could cause a problem (icing on the coil or compressor damage). So I would limit it to one or two rooms and you should not have a problem. More important is to make sure that the return air opening is in an open area, not in a room that has its door closed.

[razz]

Our cold air returns are in open spaces like the dining area and hallway so we can close the room vents as we wish during both the cooling and heating seasons.

[janharker]

I've tried closing vents in 2 different houses. The first was a finished basement. The result there was mold on the walls. The second attempt was on a first floor bedroom. The result was mold on the books.