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Bathroom Fan Ratings

    Scope
    Scope Images
    Image
    Intermittent supply and exhaust fans rated at ≤ 3 sones by manufacturer, unless rated flow ≥ 400 CFM
    Scope

    ENERGY STAR Single-Family New Homes, Version 3/3.1 (Rev. 11) requires that bathroom exhaust fans used as part of a whole-house mechanical ventilation system be ENERGY STAR qualified products.

    • ENERGY STAR exempts fans that have a rated flow of ≥ 500 CFM.

    See the Compliance Tab for links to related codes and standards and voluntary federal energy-efficiency program requirements.

    Description
    Description

    To meet ASHRAE 62.2 ventilation requirements, the HVAC designer may specify that an exhaust fan should be set for continuous or intermittent, timed operation. In homes where the bathroom exhaust fan is used as part of a whole-house mechanical ventilation system, the bathroom fan to be installed should be a model that is ENERGY STAR qualified.

    ENERGY STAR qualified ventilation fans must meet specifications ensuring higher energy efficiency with less noise. These models feature high-performance motors and improved blade design, providing better performance and longer life.

    Fans exempted from this requirement include fans with a rated flow rate equal to or greater than 500 CFM, HVAC air handlers, and remote-mounted fans. To be considered for this exemption, a remote-mounted fan must be mounted outside the habitable spaces and bathrooms and hallways and there must be at least 4 feet of ductwork between the fan and intake grille.

    For more on continuously operating exhaust fans and ASHRAE 62.2 requirements, see Intermittent Supply/Exhaust Fan Ratings and Continuous Supply/Exhaust Fan Ratings.

    How to Select ENERGY STAR-Qualified Bathroom Fans

    1. When specifying and purchasing bathroom fans that will be part of the home’s whole house mechanical ventilation strategy, select fans that are ENERGY STAR qualifying.
    2. To identify ENERGY STAR qualifying exhaust fans:
    Image
    The manufacturer’s label found on this exhaust fan housing shows a sone rating of 1.0
    The manufacturer’s label found on this exhaust fan housing shows a sone rating of 1.0
    The manufacturer’s label found on this exhaust fan housing shows a sone rating of 1.0
    Figure 1. The manufacturer’s label found on the inside of this exhaust fan housing includes an ENERGY STAR label at the lower right, indicating that this fan is an ENERGY STAR qualifying model (Source: Courtesy of PNNL). 
    Success
    Ensuring Success

    In homes where the bathroom exhaust fan is used as part of a whole-house mechanical ventilation system, the HERS rater should inspect to ensure that the fan is ENERGY STAR qualified.

    To meet the requirements of the DOE Zero Energy Ready Home program, all bathroom exhaust fans installed in the home must be ENERGY STAR qualified.

    Climate
    Climate

    No climate specific information applies.

    Training
    Right and Wrong Images
    Image
    Sone rating is greater than 3.0
    Sone rating is greater than 3.0
    Image
    Wrong - Bathroom fan should have enough suction to hold a tissue.
    Wrong - Bathroom fan should have enough suction to hold a tissue.
    Compliance
    More

    More Info.

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    References and Resources*
    Author(s)
    ENERGY STAR
    Organization(s)
    U.S. Department of Energy,
    DOE,
    ENERGY STAR
    Publication Date
    Description
    Factsheet describing the benefits of purchasing and installing ENERGY STAR rated fans and ventilation products.
    *For non-dated media, such as websites, the date listed is the date accessed.
    Contributors to this Guide

    The following authors and organizations contributed to the content in this Guide.

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