Product Description Panasonic ventilation ceiling exhaust fans produce maximum airflow and remove air impurities while operating at whisper-quiet noise levels.The Panasonic WhisperCeiling Spot Ventilation Fan comes from a line of time-tested, customer-approved and energy-efficient ventilation fans that are both quiet and powerful. Ideal for light commercial applications, it incorporates a 6” duct adapter, fits in 2x8 construction and can be used to comply with the latest codes and standards. This Panasonic fan is equipped with a thermal-cutoff fuse and a built-in damper to prevent backdraft and outside air from coming through the fan. WhisperCeiling exhaust fans feature an enclosed condenser AC motor and a double-tapered blower wheel to quietly move air at twice the static pressure as the industry standard. The double hanger-bar system, expandable up to 24”, is ideal for positioning the fan exactly where you want it. This WhisperCeiling fan is designed for user-friendly installation with detachable adaptors, firmly secured duct ends, an adjustable mounting bracket (up to 26”), fan/motor units that detach easily from the housing and uncomplicated wiring. Designed to give you continuous, trouble-free operation, this fan is made with high-quality components and permanently lubricated motors that wear at a slower pace. Panasonic fans use less energy to move larger volumes of air for less overheating and motor failure, ensuring a longer-lasting fan than other ventilation options. This fan is UL listed for tub/shower enclosure (install on a GFCI-protected circuit). It is Energy Star certified and complies with ASHRAE 62.2, LEED, IAP, EarthCraft, California Title 24 and WA Ventilation Code.Achieve quality air and energy efficiency with whisper-quiet sound levels for your spaces with the Panasonic WhisperCeiling Spot Ventilation Fan. From the Manufacturer The Panasonic FV-40VQ3 WhisperCeiling 380 CFM fan features a totally enclosed condenser motor and a double-tapered, dolphin shaped bladed blower wheel to quietly move air. A small wheel turning very fast will create more noise than a large wheel turning more slowly for a given airflow. Panasonic fans use a wide blower wheel that move a large amount of air at reduced RPMs, so they are quiet enough that you might not even know they're on. With a 3.0 sone level and rated 380 cubic feet per minute, this fan is designed to give you continuous, trouble-free operation for many years due to its high-quality components and permanently lubricated motors which wear at a slower pace. We designed the electrical configuration of this model's condenser motor to allow it to operate at lower temperatures, increasing the life of the motor and bearings. And, the fan housing is made of heavy-gauge zinc galvanized steel and painted to protect it from rust. This Energy Star qualified fan has a built-in damper to prevent back draft, which helps to prevent outside air from coming through the fan. The Panasonic FV-40VQ3 WhisperCeiling 380 CFM Ceiling Mounted Fan is covered by a manufacturer warranty for period of three years from the date of the original purchase and is sold one item per package.