WhisperCeiling ENERGY STAR® rated exhaust fans are super quiet, energy efficient and easy to install. All models also meet ASHRAE 62.2, the ventilation standard required by LEED for Homes, CA Title 24 and other green building standards. WhisperFit ENERGY STAR® rated, low profile exhaust fans feature totally enclosed AC condenser motors for long-life and energy efficiency. All models are designed with 5 5/8” height and can be installed with 4” or 3” diameter duct. Ideal for renovation and retrofit applications. All models comply with Green building IAQ standards.