THEORY

Introduction

This tool is created to facilitate the design process of a VRV system in Revit, in conjunction with the Daikin VRV Web Xpress tool. By placing Indoor and Outdoor Units in their positions in the building model and connecting them, the model can be analysed and checked according to the design rules for a VRV System. 

Preparatory Steps

Before starting Revit, make sure the Daikin Ribbon is installed. The latest version can be found here .

Before starting the design of the system, the following elements should be present

  • At least one of the following pipe types: RSen_59_PI_placeholder_con_daikin, RSen_59_PI_liquid pipe_gen_daikin with corresponding pipe segments and fittings
  • Shared Project Parameters with information for the configuration of multiple pipes where only one pipe is drawn , representing supply and return.
  • A Shared Project Information Parameter indicating the region , for commercial availability*

All those changes can be applied to your project by clicking on the Prepare Project Button in the Daikin Ribbon (Daikin -> System -> VRV). This tool will import the necessary parameters and types.

       

       

*This Parameter will not have a value from the start. Please add the country name, according to the WebXpress site (on Webxpress: tab Project, last line)


Design detail & output information

Depending on the stage of the design process, and the expectation of further changes, the design can be done in different levels of detail (LoD). In general, there are 5 levels possible: Logical, Analytical, Conceptual, Generic and Specific. Each of these detail levels gives different output information :


Creating the required input

Design Level: Logical

In a first stage, the Indoor and Outdoor Units can be placed in the model in their (estimated) position. Indoor Units can then be grouped together with an Outdoor Unit by selecting them and going to Modify|Mechanical Equipment -> Create System -> Piping. Make sure to create a system for the liquid pipe e.g. 55_RS_Refrigerant - liquid


Design Level: Analytical

To get some information about the ordering and branching of the Indoor Units in a network, a basic network has to be modelled. Follow these steps:

  1. Drawing the Main Pipe Segment: to get an idea of the order and branching of the network, an indication has to be given of where the main pipe trajectory will be. To model this, create a Pipe (Systems -> Plumbing & Piping -> Pipe) of the type RSen_59_PI_placeholder_con_daikin for the estimated trajectory of the main pipe, and the major branches (branch with multiple units). Make sure the System for the pipe is Hydronic Supply, e.g. by selecting the System Type 55_RS_Refrigerant - liquid
  2. Creating analytical connections: Select either a Unit or a Pipe, and go to Modify -> Create -> Analytical Connection and select the component to connect to. Do this for all IU in the system.
  3. Also connect the Outdoor Unit to the main pipe, by creating an analytical connection between the OU and an end of the main pipe Segment.


Design Level: Conceptual

To get a correct calculation of the diameters of pipes, and the precise ordering of Units close together, an individual branch for each Unit has to be modelled, at least in part, as a conceptual pipe:

  • To create the branch, delete the analytical connection (if created in a previous step) between the Indoor Unit and the main/major pipe, and draw a conceptual pipe that branches off from the main pipe.
  • Next, create a new analytical connection between the Indoor Unit and the end of the created conceptual pipe, or model the complete branch up to the Indoor Unit.

Design level: Generic

To graphically indicate the correct diameters and positions of all pipes, a multi-pipe approach is necessary. To do this, do the following:

  1. Model the liquid pipe as indicated in the steps above, using the Pipe Type RSen_59_PI_placeholder_daikin_thorbiq. If created previously in another Pipe Type, the type can be changed by selecting all appropriate Pipes and Fittings and employing the command Modify|Multi-Select -> Edit -> Change Type.
  2. Create a duplicate of the piping, either by retracing the trajectory manually, copying the liquid side or by creating Parallel Pipes (Systems -> Plumbing & Piping -> Parallel Pipes). Change the system of this piping to an appropriate system (e.g. 55_RS_Refrigerant - low pressure gas)
  3. In the case of Heat Recovery, repeat the process for the part of the system where a third pipe is required.
  4. If the type of an Indoor Unit is known, the Pipes in the branch to the individual Unit can be given the diameter of the connections on the Indoor Unit.

 

Design level: Specific

To create a realistic pipe trajectory, the piping can be modelled with specific Daikin components such as Refnets, to get the exact geometry. The procedure is the same as for the generic design above, except the branching will be done with refnets instead of generic fittings.

 

 

Using the Export and Validation tools

Validation tool

This tool can be used to check the model in Revit, without exporting anything. Follow these steps:

  • Go to a view where the Outdoor Unit(s) whose system(s) have to be checked, are visible.

  • Click on the Validation Button (Daikin -> System -> Validate VRV)
  • Select the Outdoor Unit(s) to include in the validation
  • Click on finish in the Options Bar

 

A pop-up window will now appear with the results of the checks performed on the system. Checks that fail the conditions will be shown in red. In the second and third columns, the Revit ID of the Outdoor and/or Indoor Units involved in the check will be listed. Clicking on this Revit ID will highlight this Unit in the view. If the Unit is not visible in this view, another view will be looked for.

 

Export WebXpress 

To export a file that can be imported in the VRV WebXpress tool (Beta Version), in addition to validating the system, this tool can be used. Follow these steps:

  • Go to a View where the Outdoor Unit(s) whose system(s) have to be checked, are visible.
  • Click on the Export JSON button (Daikin -> System -> Export WebXpress

  • Select a location and file name for the exported file.
  • Select the Outdoor Unit(s) to check.
  • Click on finish in the Options Bar.

The same pop-up window with the checks will appear. In addition two files have been created at the indicated path: a JSON file, and a text version of the validation that has been performed. 


Next Steps

The JSON file, created with the "Export WebXpress" tool can be provided to your Daikin contact for further analysis. They can upload this info, so you can analyze the system further in the VRV WebXpress environment.