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I am installing an exhaust fan in a new bathroom and have a pretty constant horizontal run to the outside. I can slope the duct up or down a few inches in about 10 feet. Is there any preferable slope for vent ducts? Are any up or down loops (or traps) helpful.
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MPoore, there is no requirement for slope, but you need to consider distance because of moisture that is being removed. you don't want that moisture to build up in a long horz run. the fewer bends you have is also better, each bend restricts air flow, so no traps either. a trap is only needed at each drain that connects to the sewer line. the water in the trap keeps sewer gases from backing into the room. make sure that each trap is also vented properly. good luck.
Jim
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MPoore,
No requirement for slope, however if you live in a cold climate you may want to slope down to the outside to keep condensation from running back to the fan and leaking into the house. The straighter and shorter the run the better. Turns and bends restrict air flow. Here in Wisconsin we vent to a sidewall or the roof. If you can avoid venting in the soffit, do so. Especially if the soffit is vented and feeds airflow to the attic. Otherwise you may just be dumping moisture into the attic via the soffit vents.
Wayne
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I am installing an exhaust fan in a new bathroom and have a pretty constant horizontal run to the outside. I can slope the duct up or down a few inches in about 10 feet. Is there any preferable slope for vent ducts? Are any up or down loops (or traps) helpful.