- Jun 11, 2014
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Founding Member
If your dryer duct runs thru the attic and you have no problems consider yourself fortunate. While the code allows a maximum dryer exhaust pipe run of 35 LF, most dryer manufacturers allow less than that. Every 90 degree angle in the 4" smooth wall pipe is equal to 5 LF. The vent hood itself is an even great restriction and then add to that the 8 foot long usually corrugated transition connection behind the dryer. Now try and push the exhaust VERTICALLY up through the attic. The lint will fall back to the nearest turn in the pipe. Most dryer exhaust fans are barely capable of doing their job under the most perfect conditions. Restricted dryer vents cause excessive energy usage through drying times, premature appliance failure and fires.