Broan-NuTone 353 Gable Mount Attic and Garage Ventilation Fan User Manual

1. Product Overview

The Broan-NuTone 353 Powered Attic and Garage Ventilation Fan is designed to prevent heat and moisture buildup in attics and garages. Proper ventilation helps maintain a cooler, drier environment, which can extend the lifespan of your roof and air conditioning system, while also reducing energy costs. This fan is suitable for ventilating one, two, or three-car garages, whether attached or detached from the home, effectively combating heat, humidity, and unwanted odors.

Key features include:

• Gable Mount Installation: Specifically designed for gable installation, requiring permanent electrical wiring and grounding. Extension cords must not be used.
• Efficient Operation: Delivers 760 Cubic Feet Per Minute (CFM) of airflow. Features a precision-balanced 14-inch metal blade for maximum air movement.
• Durable Construction: Constructed with galvanized steel housing for enhanced strength and longevity.
• Automatic Control: Equipped with an adjustable, built-in thermostat for automatic operation based on temperature.
• Dimensions: Housing measures 15 inches in diameter and 8 inches deep, with a 14-inch diameter steel blade.

Image 1.1: Broan-NuTone 353 Gable Mount Attic and Garage Ventilation Fan. This image shows the complete fan unit, highlighting its robust construction and blade design.

2. Safety Information

WARNING: To reduce the risk of fire, electric shock, or injury to persons, observe the following:

• Installation work and electrical wiring must be done by qualified person(s) in accordance with all applicable codes and standards, including fire-rated construction codes and standards.
• Always disconnect power at the service panel before wiring or servicing the unit.
• This unit requires permanent electrical wiring and grounding. Do not use with an electrical extension cord.
• This product is intended for gable installation only.
• California Proposition 65 Warning: This product may contain chemicals known to the State of California to cause cancer, birth defects, or other reproductive harm.

3. Setup and Installation

Proper installation is crucial for the efficient and safe operation of your Broan-NuTone 353 fan. This fan is designed for gable mounting. Ensure you have adequate soffit ventilation to allow for proper airflow.

3.1. Pre-Installation Considerations

• Ventilation Requirements: Calculate the required Cubic Feet Per Minute (CFM) for your attic or garage. A general guideline is to multiply the attic volume (Length x Width x Height) by 10 air changes per hour, then divide by 60 minutes/hour to get CFM. Ensure sufficient soffit vent area (approximately 0.48 square inches per CFM).
• Electrical Wiring: The fan requires permanent 120-volt AC electrical wiring and proper grounding. Consult a qualified electrician if you are unsure about electrical connections.
• Mounting Location: Identify a suitable gable vent opening. The fan housing is 15 inches in diameter.

Image 3.1: Ventilation Calculation Guide. This image provides a step-by-step guide to calculate the recommended CFM and minimum soffit vent area for effective ventilation.

3.2. Mounting the Fan

The fan is typically mounted to a wooden frame constructed around the gable vent opening. This frame provides a secure and stable base for the fan.

1. Prepare the Mounting Board: Cut a piece of plywood (e.g., 21 inches square) to fit securely within the gable vent framing. Trace the fan's duct shape onto the plywood and cut out the opening.
2. Pre-wire the Fan: Before mounting, connect 14/2 electrical wire to the fan's junction box. This makes wiring easier than doing it in a confined attic space.
3. Secure the Fan to the Board: Center the fan on the prepared plywood board. Use 1/2-inch wood screws for the inner mounting holes and 1 1/2-inch wood screws for the outermost holes, ensuring they penetrate into the studs of the frame.
4. Install the Assembly: Position the fan and plywood assembly into the gable vent opening. Secure it to the existing attic framing (e.g., 2x4s) using screws. Start with a few screws to support the unit, then add more to ensure it is very secure.
5. Run Electrical Wiring: Route the electrical wire from the fan along the attic ridge to your power source (e.g., an existing outlet converted to a switch). Secure the wire with tacks every few feet.
6. Connect to Power: Wire the fan to a dedicated switch or power source according to local electrical codes.

Image 3.2: Gable Mount Fan Installation. This image illustrates the Broan 353 fan mounted within a wooden frame in a gable vent opening, showing the electrical connection box.

Image 3.3: Fan Blade and Housing Dimensions. This image provides a visual reference for the fan's dimensions, including the 16-inch overall diameter and 14-inch blade.

4. Operating Instructions

The Broan-NuTone 353 fan operates automatically via its built-in adjustable thermostat.

1. Power On: Ensure the fan is connected to a permanent power source and the wall switch (if installed) is in the "ON" position.
2. Thermostat Adjustment: The thermostat is located within the fan shroud. It controls when the fan activates based on the attic or garage temperature.
   • To adjust the temperature setting, access the thermostat and rotate the dial to your desired activation temperature.
   • Consider that the thermostat inside the shroud may register a slightly lower temperature than the overall attic temperature due to its proximity to the gable vent and airflow. You may need to set it lower than your desired attic temperature to achieve optimal operation.
   • Common settings range from 90°F to 110°F (32°C to 43°C).
3. Automatic Operation: Once set, the fan will automatically turn on when the temperature at the thermostat reaches the set point and turn off when the temperature drops below it.

5. Maintenance

Regular maintenance helps ensure the longevity and efficient operation of your ventilation fan.

• Annual Inspection: Annually, or more frequently in dusty environments, inspect the fan blades and motor for dust and debris buildup.
• Cleaning: Disconnect power to the fan at the circuit breaker before cleaning. Use a soft cloth or brush to gently remove any accumulated dust or dirt from the blades and motor housing. Do not use water or liquid cleaners directly on electrical components.
• Check for Obstructions: Ensure the gable vent opening and fan blades are free from obstructions such as bird nests, leaves, or other debris.
• Motor Lubrication: The fan motor is typically permanently lubricated and does not require additional oiling. Refer to the motor's specific instructions if available.

6. Troubleshooting

If your Broan-NuTone 353 fan is not operating as expected, refer to the following common issues and solutions:

7. Specifications

8. Warranty and Support

For warranty information, technical support, or to purchase replacement parts, please contact Broan-NuTone customer service or visit their official website. Keep your purchase receipt as proof of purchase for warranty claims.

Broan-NuTone Official Website: www.broan-nutone.com