The fan should be placed between the shower and toilet to ensure efficient circulation of air and ventilation of moisture.
Aiming for the space in between the shower and bathroom door gives the vent fan the best chance to remove the humid, unwanted air as well as pull in fresh air from the rest of the house.
Follow the Moisture
First, the fan should be located in the area of the bathroom that is exposed to the most moisture. This is usually the area over the bathtub or shower. You can place the fan directly over the bathtub or shower base, but it's sufficient to position it anywhere near the bathing area.
Behind or within the Wall: In most cases, the vent pipe for a toilet should run vertically from the toilet's waste pipe (known as the closet bend) and extend upward to connect with the main vent stack or a branch vent line that ultimately exits through the roof of your home.
For pipes that have a diameter of 3 inches the distance is 6 feet and for a 4-inch pipe the most it should be away from the vent is 10 feet. Keep in mind that toilets have their own traps so there is no need to have one on the drain line, but it still must have a vent.
Exhaust ducts should always terminate outdoors (refer to applicable codes for vent termination clearance requirements). Running exhaust ductwork up to a vented attic or just in front of an attic vent (gable, ridge, or soffit) is not sufficient. The exhaust should be fully ducted to a point exterior to the home.
That's why it's fine to have bathroom vents in a basement or lower floors to leave through the side of the home. To help your attic stay clear of mold or mildew, make sure all exhaust fans running through the attic leave through the roof. For one, you'll lessen the chance of the warm air getting back into the attic.
Where is the best location to install my bathroom exhaust fan? Typically a bathroom exhaust fan should be mounted as close to or inside (if rated for tub shower use) to the shower or tub as possible. This will maximize the effectiveness of the unit. Units located in a powder room, should be directly over the toilet.
Choose a fan that can ventilate at least 1 CFM per square foot of room. So, for an 80 square foot bathroom, select an 80 CFM fan. For bathrooms 50 square feet and smaller, it's recommended you purchase a bath fan designed for small rooms. In other words, choose under 79 CFM bath fans.
Flexible duct is acceptable for a bathroom exhaust fan. Approved by building codes-Chapter 15 of the International Residential Code (IRC), it is available in PVC, PVC coated aluminum, aluminum and insulated aluminum.
The National Electrical Code (NEC) does not require bathroom exhaust fans to be GFCI protected, however, there is this bit in Article 110. 110.3 Examination, Identification, Installation, and Use of Equipment.
Extractor fans work best when they are fitted as near as possible to the source of moisture in the air. For many people, this will be over their shower enclosure or bath. However, as bathroom fans are an electrical item, it is vital that you ensure you have the correct IP rating for this bathroom zone.
To fulfill the local exhaust airflow requirements of ASHRAE 62.2 (2010) and the International Residential Code (IRC 2021, Section M1507), bathroom fans should have a mechanical exhaust capacity of ≥ 50 cfm for intermittent operation or ≥ 20 cfm of ventilation when operated continuously.
This fan will remove any moisture that's in the air by sucking it into a duct that will redirect it to a vent leading outside. It's important to have this fan on during showers, otherwise, moisture will settle onto the walls and fixtures.
Other venting options includes running the duct up through the roof or down through the soffit. Note that the bathroom vent fan must always exhaust to the outdoors; never allow the duct to simply blow into an attic, crawlspace or other enclosed area.
You should place outward-facing fans on the warmer side of your home to blow the hot air out and inward-facing fans on the cooler side to draw cool air in, says Barry Jacobs, vice president of product development at Comfort Zone, a home environment product company.
The easiest way to check if the van is ventilating properly is to take a Kleenex or single square of toilet paper and place it along the fan while it's running. If the fan holds up the paper and keeps it attached, then it's working properly.
In simplest terms, bathroom exhaust fans have a motor that runs on electricity. That motor powers a fan, which draws moist air up through the fan and into ductwork (generally speaking) that – if installed correctly – exhausts to the outside, often through a soffit vent or eave vent hood.
The main purpose of the bath fan is to remove steam and moisture from the air. So the fan should be located over the primary source of moisure in the room – your shower.
A ventilation fan brings fresh air into a space, improving circulation, while an exhaust fan removes stale, humid, or polluted air, typically from kitchens or bathrooms. The key difference lies in airflow direction: ventilation fans pull outdoor air in, while exhaust fans push indoor air out.
Yes, Flex ducts are a perfectly valid option to use a conduit for your bathroom exhaust fan. The manipulatable nature of flexible ducts allows them to fit into environments in which the connection to the outside is not a straight line.
Non-combustion appliance vents should be located 3 feet from any building opening. Avoid locating exhaust vents within 10 feet above outdoor living areas (e.g. deck, patio, play yard) Avoid locating exhaust vents beneath canopies, overhangs or within recessed openings.
For bathrooms up to 100 square feet in area, HVI recommends that an exhaust fan provide 1 CFM per square foot (approximately eight air changes per hour) to properly ventilate the bathroom.