randyb Posted January 13, 2010 Report Share Posted January 13, 2010 Hello, I had my home built in 04 with an unfinished basement. Minnesota winters get cold, and every winter it seems I get a great amount of moisture (ok...water) dripping off of the 4" insulated fresh air vent tube. The 1st winter we noticed this and had the contractor take a look, he replaced about the 1st 7' of insulated tubing. The next winter it did it again...builder went bankrupted. anyway this past fall I decided to insulate the celing for noise and hoping it would take care of my problem with the moisture. Nope..i just removed the sheetrock to check on it and it's wet up there again. i put up 5/8" (Noise) r19 (noise & insulating value) and those darn fresh air vents are soaking wet inside it's insulation. course it leaks right out of it because they replaced 7' of it and only taped it. The two fresh air tubes run along the west wall to the north wall where they are vented. In that area of the ceiling, like the next rafter over to the east is the heat vent for that room in the basement, so there is definately heat with in the general area of the insulated fresh air vents. I did put r19 all around my heat vent just to help keep the ducting somewhat insulated from the cool air up there. The rest of the basement is not yet insulated in the ceiling, althought all the walls are insulated and sheetrocked. I pulled the sheetrock on the wall just under this area and the walls are dry, just the darn fresh air vent is cold and wet. anyway..how can I stop the moisture from building up? I'd like to finish this basement but I'm afraid of all of this moisture. I have a choice furnace, direct vent system to the west side of the house (about a 10' run), the two fresh air vents go out the north side of the house (about a 35' run). The two fresh air vents..one is dropped next to the furnaced 7" off the ground and the second one goes directly into the fresh air side of the furnace. I do run a humidifier in the basement next to the fresh air intake by the furnace, and have a humidistat upstairs and downstairs, I keep the humidity about 32 to 38 percent. Last week I shut it off for three days (temps outside where like -20 below) and it was so dry the sinuses hurt. a few pictures... in/out for furnace fresh air vent into furnace fresh air side fresh air vent 7" off the floor in/out with exhaust heading towards outside Click to Enlarge 40.86 KB Click to Enlarge 58.4 KB Click to Enlarge 46.96 KB Click to Enlarge 53.21 KB my last house we had the heat exchanger system and had no problems. do these insulated fresh air vents (even in a fully finished basement) always get moisture in them? but just don't leak normally? Anyone have some direction for me on this. Thanks for you time, Randy Quote Link to comment Share on other sites More sharing options...
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