Many people do not realize that almost all VRF manufacturers do not allow the use of a standard refrigeration T (with the exception of Mitsubishi). The majority of manufacturers require the installation of a specialty fitting that they provide that is called a Refnet or Y-Branch Fitting (terminology depends on manufacturer). In addition to the specialty fitting itself each manufacturer has specific piping requirements for this fitting that must be adhered to for proper system function.
For the purpose of this post we are going to explore the impact of the refnet in the estimating, coordination, and installation phases of a VRF project. We will be using the piping rules specific to the LG & Daikin VRF Systems.