Vent Bathroom Fan Through Soffit Or Roof

A down through soffit exhaust vent design by leaving warm air in the exhaust duct when the fan is off creates a heat trap that reduces heat loss out of the bathroom through the exhaust fan duct when the fan is off in comparison with up routed vents or even horizontal vents through a gable end wall.

Vent bathroom fan through soffit or roof.

Opposed to the traditional practices of venting a bathroom fan through a side wall or roof you can also vent it through a soffit which is much preferable in some cases as we will see in this article. Venting through a roof vent or exhausting them in the attic could cause moisture problems and rot. Then drill a hole on the roof top. That s why wall terminations are preferable to soffit terminations.

There is no definitive answer in the codes that pertain to where the air must vent out of the house. And the closer the termination is to the soffit vents that supply ventilation air to the attic the more likely that moisture from the bathroom will be drawn into the attic. In cold weather it forms icicles. The good majority of bathroom fans are vented through the roof while some people are choosing to soffit vent them as an alternate.

The best exhaust fan venting is through smooth rigid ducts with taped joints and screwed to a special vent hood. Vent your bath and kitchen exhaust fans through the roof through a special roof hood. And while both a roof vent and an overhang vent perform this task there is one big difference. If there are bends or dips then that means the moisture in the air can accumulate in those low parts from condensation.

The roof contractor recommends the soffit to minimize protrusions through the roof. So then the argument is that your humid bathroom exhaust comes out and is sucked back into the attic by the soffit vents built into most roof attic systems. To vent a bath fan through the roof you must first prepare a ductwork connecting the roof top to the bathroom. When a bathroom exhaust duct terminates in a soffit it drips.

A soffit exhaust vent cover is installed in a straight line as much as possible from the bathroom exhaust fan. However natural air flow from the outside will bring the moist air back into the attic through the soffit vents kind of like a vacuum. If you are also amongst the people who are interested in avoiding making a hole in the roof and get the deed done using a soffit you have come to the right place. I am getting a new roof installed and tear off and likely a lot of plywood and am simultaneously getting a new bath vent fan.

As the warm moist air leaves the bathroom through a soffit it leaves in a downward motion. I have gotten mixed opinions on whether to vent the new fan through the roof or through the soffit eave.