Reducing vibration transmission from a wall-mounted VRF system

Modern HVAC systems for residential applications have advanced significantly in comparison to the technology that has been used in America since the 1960s and 1970s. New systems include variable refrigerant flow (VRF) technology, which allows systems to operate as reversible heat pumps, handling both heating and cooling powered only with electricity. This improved functionality and higher efficiency are instrumental in the drive to replace older systems. The VRF technology also allows compressors to operate at variable speeds, to match the actual demand of the heating or cooling. In addition, the new residential systems can be very quiet and, in some cases, not an issue given their low sound emission. These systems are also smaller and or narrower and can be mounted to exterior walls when there are few options on horizontal surfaces at grade or on a roof. This paper will discuss the impacts of a wall-mounted system on a residential house, where it was wall-mounted. The paper will also cover how the installation was modified to isolate the system more effectively from the exterior wall of the adjacent bedroom space, significantly reducing the impact to the interior.