Modelling Variable Refrigerant Flow (VRF) HVAC systems' hardship

We have had the same concern when specifying VRF/VRV heat pump systems on our projects. The most up to date information I have on the topic was provided to me by Neetu Singh of The Green Engineer: "The best program to simulate a VRF heat pump system is Energy Pro . As far as I know all the VRF manufacturers have worked with the developers of Energy Pro to build in their system specific efficiency libraries. Versions of eQuest 3.63 and later allow you to simulate variable speed compressor (select system type PVVT), and then depending on whether the system is a heat recovery type or not, there are certain tricks you have to apply to make sure that the answer is pretty close to what the VRF would be in performance. Still there are no custom libraries available in eQuest yet. I read somewhere that people are working on building these into eQuest but nothing has been released yet. I used eQuest for [a recent non-heat recovery VRF project] because the non-heat recovery types are quick to simulate in eQuest. Actually TRACE also lets you simulate these. If you go on BSUG yahoo group, there is a ppt. available there which gives a step wise method to simulate these systems both in eQuest and TRACE."