Solution: Unbag the wind turbines.<\/strong><\/p>\n\n\n\n It\u2019s impossible for a covered attic exhaust vent to work if it\u2019s smothered under a bag. Attic ventilation is supposed to provide year-round benefits, fighting heat buildup in the warmer weather and moisture buildup in the colder weather. It\u2019s sometimes forgotten (and maybe never known) that occupants of a house generate water vapor daily through activities such as cooking, cleaning, bathing, breathing, etc. It amounts to 2-4 gallons per day for the average family of four. That warm, moist air can make its way into the colder attic in the winter months, where it can condense and cause trouble as water droplets and frost.<\/p>\n\n\n\n Problem: Bath Fan Ductwork Terminating in the Attic Damages Roof<\/strong><\/p>\n\n\n\n Solution: Run the bath fan ductwork either vertically through the roof or out the side gable wall.<\/strong><\/p>\n\n\n\n Even a perfectly balanced attic ventilation system cannot handle the quantity of moisture dumped into the attic by the bath fan. It overwhelms the system. That moisture should be vented directly to the outdoors without any pitstops into the attic. In the home pictured here, Trevor Atwell found three bathroom fans venting directly into the attic. He also found a lot of rotted sheathing.<\/p>\n\n\n\n Problem: Painted Soffit Vents Result in Reduced Intake Airflow<\/strong><\/p>\n\n\n\n Solution: Buy pre-painted soffits, or paint them more carefully, or replace them with new vents.<\/strong><\/p>\n\n\n\n Soffit vents have a specified amount of Net Free Area (airflow capability) when they are manufactured. For example, 9 square inches of NFA per linear foot. That amount, by the way, would balance nicely with a ridge vent (exhaust vent) that is capable of 18 square inches of Net Free Area per linear foot (9 NFA at the soffit on the left of the ridge vent + 9 NFA at the soffit on the ridge of the ridge vent = 18 NFA at the peak of the roof). But the airflow capability of the soffit is reduced if the vent openings become clogged or blocked because of a careless paint job. While house exterior colors are important, don\u2019t sacrifice attic ventilation performance. It\u2019s possible to have both a nicely painted soffit and it\u2019s full, intended net free area (airflow capability). <\/em><\/strong><\/p>\n\n\n\n Problem: Two Rows of Box Vents = One Path of Inefficient Airflow<\/strong><\/p>\n\n\n\n Solution: Always keep attic exhaust vents in one row<\/strong>.<\/p>\n\n\n\n Let\u2019s cut to the chase. If it takes two rows of attic exhaust vents to meet the attic\u2019s exhaust ventilation needs, it\u2019s time to find another category of exhaust (maybe horizontal ridge vent; or diagonal hip ridge vent; or a combination of horizontal and diagonal ridge vent; or a power fan). But when attic exhaust vents are aligned in two rows, the primary path of the airflow will be from one row to the next because air will allows follow the path of least resistance seeking the closest exit point from its entry point. The intake vents in the soffit or low on the roof\u2019s edge are supposed to be the intake vents. The pictured scenario here is producing inefficient attic airflow and could cause one row of box vents to ingest weather.<\/p>\n\n\n\n Problem: Mixed Types of Attic Exhaust Vents = Problematic Airflow<\/strong><\/p>\n\n\n\n Solution: Only use one type of attic exhaust vent on the same roof above a common attic.<\/strong><\/p>\n\n\n\n Regardless what combination of two or more different types of attic exhaust vents either the homeowner demands (we\u2019ve heard the stories) or a well-intended but misguided roofing contractor recommends (it\u2019s happening), do not mix two different types of attic exhaust vents on the same roof above a common attic. Pictured here are wind turbines with ridge vents; box vents with ridge vents; solar powered fans with box vents; and traditional electric power fans with ridge vents. Now shown is the all-time classic: Gable-end louvers with any other type of attic exhaust.<\/p>\n\n\n\n![\"\"](\"\/wp-content\/uploads\/2020\/08\/Screen-Shot-2020-08-01-at-8.39.54-PM-1024x730.png\")
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