The Learning Environment
The six core features of the XR2ACH application – CAD visualization, simulation scenarios, multi-user collaboration, knowledge quiz and learning analytics, flexibility and open standards.
The XR2ACH application is an extended reality learning environment for initial and continuing training in refrigeration, air-conditioning and heat-pump technology. It is designed to be open source, extensible and cross-platform.
Six core features
| Feature | What it does |
|---|---|
| CAD visualization | Interactive, true-to-scale 3D models of real refrigeration equipment – for conceptual knowledge and spatial understanding. |
| Simulation scenarios | Safe practice of procedural knowledge: the core processes of the trade, including the documentation they require. |
| Multi-user collaboration | Several learners and trainers in one shared virtual room – on a local network or via a server. Also in the same physical room (passthrough). |
| Knowledge quiz & learning analytics | Questions tied to learning objectives, built into the flow; optional connection to a learning management system (Moodle). |
| Flexibility | Three operating levels, from a single headset to personalized use with a server (Technology & Operation). |
| Open standards | OpenXR for device compatibility, xAPI for learning analytics, OpenID Connect for sign-in. |
CAD visualization: compressors from real industrial data
The first models are compressors, the heart of the refrigeration cycle. Three models based on industrial CAD data from BITZER are available with animations:
| Model | Type | Enclosure | Refrigerant | Typical applications | |
|---|---|---|---|---|---|
 | 4NESP-22Z-40P | Reciprocating, multi-cylinder | Semi-hermetic | A1 (e.g. R134a) | Supermarket compound systems, cold stores, commercial kitchens |
 | VSK3162-15Y | Screw | Hermetic | A1 (e.g. R134a) | Rail vehicle air-conditioning, chillers, process cooling |
 | OS.A95 | Screw | Open | B2L (R717, ammonia) | Industrial freezer stores, food processing, ice rinks |
Sectional view of the 4NESP compressor in passthrough mode.
The models can be rotated, cut open, taken apart (exploded view) and made transparent. Rolling-piston and scroll compressors for heat pumps and air-conditioners are planned, as is a reciprocating compressor for CO₂ (R744). Expansion valves, heat exchangers and complete refrigeration circuits are in progress.
Simulation scenarios
| Scenario | Status | Content |
|---|---|---|
| Leak detection and leak testing | Tested (Leonberg, Neuwied, Maintal) | Checking the environment and the system’s state; direct methods (electronic leak detectors, leak detection spray) on virtual replicas of the training systems |
| Service and commissioning | In development | From visual inspection to documentation – in 13 steps |
| Pipework and brazing | Planned | Measuring, cutting, bending; brazing without fire risk, fumes or copper waste |
The leak detection flow
- Get to know the room and check environment Windows, solvents, system state
- Make the system safe
- Identify the medium (Quiz question)
- Choose the tool (Quiz question – a wrong answer blocks progress)
- Prepare the electronic leak detector Optionally check it on a test leak
- Find, assess and mark the leaks
- Final check Missing, wrong and unused markers cost points
- Result and progress
Leaks are found with the electronic leak detector and marked from a menu on the hand.
The safety logic follows practice: if solvents are in the air, the room must be ventilated; a running system is switched off before an electronic search; not every device detects every medium.
The service and commissioning flow
- Safety and environment
- Visual inspection and flow diagram
- Prepare the gauges
- Prepare and carry out recovery (repairs only)
- Pressure strength test
- Coarse leak test
- Evacuation
- Charge refrigerant
- Fine leak test
- Test run
- Remove the gauges
- Documentation and completion Nameplate, logbook
- Final feedback
Commissioning: manifold gauges and hoses on the virtual system.
A help system accompanies every step with graded hints, live values and a debrief. The order is binding; steps done correctly stay done. The scenario is being developed with trainers of the Bundesfachschule Kälte-Klima-Technik.
Learning together
In the multi-user room, several people work on the same system: one person searches, the others advise; a trainer can show and explain.
Where the features fit didactically
Which feature suits which learning objective is described on the Didactics page. How the scenarios fit into inter-company training is explained under In Vocational Training.