Efficient ductless ERV: The TwinFresh Expert RW1-85-2 V.2 ductless energy recovery ventilator provides fresh filtered air indoors while exhausting stale air outdoors, reducing HVAC energy consumption and utility bills Wall Thickness: The Twinfresh Expert RW1-85-2 ERV ventilation fan can be installed through walls with a minimum thickness of 5-7/8 inches and a maximum thickness of 19-5/8 inches. If you require a short duct length, we recommend our Twinfresh Comfo Ventilation Fan, which can be installed in walls with a minimum thickness of 4-3/4 inches and a maximum thickness of 8-7/8 inches Wifi Control From Your Phone: Once the unit has been connected to wifi, it can be controlled from an Android or IOS device. You can also synchronize multiple ventilators via Wi-Fi for simultaneous operation (see instructional video below to learn how to connect your device) Sound Level and Air Filtration: From 0.5 to 2.1 sones at 10 ft during operation. All Twinfresh units come standard with MERV 5 filtration (we also offer a MERV 13 as an option) Stainless Steel Outer Hood: Durable stainless steel corrosion-resistant outer hood designed for long-lasting outdoor protection ETL certified for safety and compliance with building standards, featuring a plug-and-play design that saves time and cost by eliminating complex ductwork and simplifying installation The TwinFresh Expert RW1-85-2 V.2 ductless energy recovery ventilator provides a smart, energy-efficient solution for improving indoor air quality across commercial, residential, and retrofit applications. Designed for walls 5-7/8 to 19-5/8 inches thick, this fan supplies continuous fresh, filtered air while exhausting stale air, significantly reducing HVAC load and lowering energy bills. Control your ventilation easily with Wi-Fi-enabled smartphone integration supporting multi-unit syncing, giving you control from anywhere. The robust, corrosion-resistant stainless steel outer hood ensures durability for indoor and outdoor use. Perfect for multiple rooms inside the home, apartments, offices, tiny homes, commercial retrofit projects, and other common communal spaced. The TwinFresh Expert RW1-85-2 offers an ETL-certified, plug-and-play solution. Improve air quality, reduce energy use, and enhance comfort with TwinFresh Expert.