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Confused about venting a bathroom fan

17 years ago

I have a 1950s ranch home with two bathrooms that have no ventilation. I purchased two Hunter light/vent combos. Both will be installed were the current light fixture is. It is a direct shot of less than 4 feet to the soffit. I have read about how you are not supposed to vent to the attic or the soffit b/c of moisture issues. I cannot install a roof vent right now and a wall vent is out of the question because they are brick.

Why can't I run the exhaust pipe to the soffit and then out an independent exhaust vent dedicated to the bathroom fan and installed in the soffit that is 4 feet from the other soffit intakes vents on either side? I know there is a risk of moisture ending up back in the attic, but will it really travel out of my bathroom/soffit exhasut and then 4 feet to the left or the right and then back into the attic?

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Comments (2)

tom_p_pa
17 years ago
Bit confused at your plan, but I did read this:

"but will it really travel out of my bathroom/soffit exhasut and then 4 feet to the left or the right and then back into the attic"

Bottom line..you cannot exhaust your fan into the attic...it must discharge to the exterior of your home. The ducts can travel through the attic, but cannot discharge into the attic.
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johnmari
17 years ago
Think you missed something, Tom. She doesn't want to vent into the attic. She wants to vent OUTSIDE by punching THROUGH a closed section of the soffit. That section of soffit is 4 feet from any vents.

FWIW, it is not the optimal solution but it is extremely common where I live because of heavy snow and ice buildup on roofs which can block roof vents; it does meet code, and it is a hell of a lot better than no fan at all or just venting into the attic as so many nimrods do. Our upstairs bath fan is vented out through the soffit because there was nowhere to go in a side wall due to the angle of the roof, going through the roof would have tripled the cost of the installation, and going through the gable end would have made much too long a duct run for the fan we needed to use. (Long story I will not go into here.) Since our house had continuous soffit vents, the vents for several feet in either direction from the outlet were blocked off so the warm, moist air wouldn't rise back into the soffit. There is a special duct outlet made specifically for going through a soffit, it looks like a short (maybe 6" long) cylindrical pipe with a grille at the end. A hole is cut in the soffit, the outlet pushed through from the outside and glued in place. Then the duct is attached to this. One with a screen inside the grille will keep insects from coming in and taking up residence in your attic. Make sure you use insulated duct so you don't get condensation in the duct (and be careful when you open the box with the insulated duct - it's packaged compressed and ours sprang out like those peanut cans with the "snake" inside!).
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