I brought a "new" house, that house was built in 1982 and in the basement there is a pipe that raise right to the attic, there is a small metal register in the ceiling of the basement. They said me that it's to remove humidity and it's acting like a cheminey in summer, I have to cap it in the attic before the winter come...
If I install an A/C should I permanently close that pipe? If I increase ventilation in the attic, by adding an attic ventilator or some high performance passive air ventilator for the attic, will this pipe draw my relatively cool air right to my attic?
That was the first time I heard of this passive system, could some one explain in detail what it's for and if it still recommended to operate it and what have replaced this system since then ?
I have heard of pipes bieng run from outside to the utility room for combustion air when the utility room door was closed.
but I have no idea what this guy was smoking when he tried to tell you that it was a dehumidifier.:p
maybe it was a return that never got connected in the second floor. meaning, maybe the heating guy roughed the pipe into the attic in case he needed more return air from the second floor, then decided not to connect it after the drywall went in. then when the builder asked him what the pipe was, he made up some nonsense to get the builder off of his back.
Not to say that's what it is, but it could be a possible situation.
Mate It is simply an exhaust. Hot air rises so in summer the heat in your basement will rise up the "chimmney" or cool air will fall. I'd expect that it would utilise the venturi effect to circulate fresh air. Yes, in winter it may be an idea to block it to stp cold air "refrigerating" your basement.