The LEED for Homes v4 rating system addresses acoustic comfort by setting maximum sound levels for mechanical ventilation to ensure occupants are not discouraged from using it due to noise. Under the Indoor Environmental Quality (EQ) credit for Indoor Contaminant Control, a requirement for earning the point is that all bathroom exhaust fans must have a maximum sound rating of 1.0 sone. This ensures that the fans can operate effectively to remove moisture and pollutants without creating an acoustically disruptive environment, thereby balancing indoor air quality with occupant comfort.

A. 0.5: This is a quieter performance level than the LEED maximum; while a 0.5 sone fan would comply, it is not the specified threshold.

C. 2: This sound level exceeds the maximum 1.0 sone rating permitted for bathroom exhaust fans to meet the credit requirements.

D. 3: This is the maximum sone level specified for kitchen exhaust fans (range hoods), not for the quieter bathroom environment.

1. U.S. Green Building Council. (2016). LEED v4 for Homes Design and Construction. Washington, DC: U.S. Green Building Council. Page 131, EQ Credit: Indoor Contaminant Control, Option 2. Local Exhaust, Requirement 2.

2. U.S. Green Building Council. (2020). LEED v4.1 Residential Single Family. Washington, DC: U.S. Green Building Council. Page 111, EQ Credit: Enhanced Indoor Air Quality, Option 2. Local Exhaust, Requirement 2.

3. University of Florida, Program for Resource Efficient Communities. (n.d.). LEED for Homes v4 Project Checklist. Page 10, EQ Prerequisite: Indoor Contaminant Control. Retrieved from the University of Florida's official domain, which specifies, "All bathroom exhaust fans are ENERGY STAR qualified or have a maximum sound rating of 1.0 sone."