Not every building is the same, so why would every HVAC setup be the same? Whether you’re fitting out a premium home, a commercial office tower, or a mixed-use development with hydronic heating and VRV cooling, the monitoring and control approach needs to match the complexity of the system.
This guide breaks down the most common HVAC configurations we see across Australian projects — and which Airnexus products are designed for each. No jargon, no hard sell, just a clear explanation of what fits where.
Understanding Your System Type
Before you can pick the right products, you need to know what kind of system you’re working with. Most buildings fall into one of three broad categories — and a lot of premium builds combine two or three.
VRV / VRF Systems (Variable Refrigerant Volume / Flow)
The workhorse of modern commercial and luxury residential HVAC. One outdoor unit feeds multiple indoor units — the fan coil units, or FCUs — and each FCU can be controlled individually. You’ll find VRV/VRF in offices, hotels, retail, and high-end homes. The major Japanese and Korean manufacturers all build these systems.
Why people choose it: individual zone control, high energy efficiency, and quiet operation. The same system can heat one room while cooling another, which is why it suits open-plan commercial spaces and multi-bedroom homes.
Hydronic Systems
Hydronic means water. Hot or chilled water circulates through pipes to deliver comfort — underfloor heating loops, radiator panels, chilled beams, buffer tanks, and fan coil heat exchangers. You’ll see hydronic in luxury homes, aged care facilities, hospitals, and cold-climate builds where radiant heating is the expectation.
Why people choose it: genuinely comfortable radiant heat, almost silent operation, and excellent pairing with heat pumps and solar thermal. Hydronic is often combined with a VRV/VRF system — VRV handles cooling through the summer, hydronic handles the winter heating load.
Ducted Zoning Systems
The traditional Australian setup. A single outdoor unit pushes conditioned air through a ducted network, and motorised dampers open and close to decide which zones get air at any moment. It’s common in standard residential builds, small commercial, and retrofits where budget matters.
Why people choose it: simplicity and cost. For smaller buildings with straightforward layouts, ducted zoning gets the job done without the complexity or capital outlay of VRV.
Which Setup Matches Your Project?
Click a card below to see the Airnexus products that suit each system type. Only one opens at a time — pick the setup that best matches your build.
Find Your Setup
Tap a card to reveal the recommended Airnexus products
Commercial / Luxury VRV
Multi-zone cooling and heating with individual unit control
VRV + Hydronic Hybrid
VRV for cooling, hydronic for heating — the premium combination
Ducted Zoning
Traditional ducted system with zone control
Commercial / Luxury VRV/VRF
This is where the Nexus platform really shines. VRV/VRF systems generate a massive amount of data — discharge temperatures, evaporating pressures, compressor frequencies, refrigerant states — and without proper monitoring, problems go undetected until something fails.
- Nexus 32 Controller — for large sites with up to 32 indoor units per gateway. Ideal for commercial offices, hotels, and retail centres.
- Nexus 16 Gateway — for mid-sized installations like office floors, large homes, and boutique hotels. Supports up to 16 FCUs.
- Nexus 8 Gateway — for smaller VRV setups such as luxury apartments, small retail, or individual floors. Up to 8 FCUs.
- Nexus Link — the cloud communication gateway that connects your controllers to Nexus iQ™. One per site.
- Discreet Sensor — wired temperature and humidity sensor for accurate zone monitoring.
- Sensor Expansion — adds up to 16 temperature monitoring points per controller, ideal for large buildings needing comprehensive coverage.
With this setup, you get real-time visibility of every indoor and outdoor unit, fault detection before failures happen, energy analytics, and full remote control from anywhere.
VRV + Hydronic Hybrid
Luxury homes and premium commercial builds increasingly combine VRV for cooling with hydronic systems for heating — underfloor heating, radiator panels, buffer tanks, and heat pumps. This dual-system approach gives the best comfort but adds complexity. You need monitoring across both systems.
- Nexus 32, Nexus 16, or Nexus 8 — sized to match your VRV load. Handles all VRV/VRF monitoring and control.
- Hydronic Controller — purpose-built for hydronic heating systems. Monitors flow temperatures, pump status, valve positions, and buffer tank levels.
- Universal Expansion 8, 11, or 16 — for everything else: circulation pump switching, solenoid valve control, temperature sensor inputs, domestic hot water recirculation, and heat pump integration.
- Nexus Geo — if the system includes geothermal heat pumps, this dedicated controller handles ground-source monitoring.
- Nexus Link — cloud connectivity for the whole site.
- Discreet Sensor — zone-by-zone temperature monitoring.
The combination of a VRV controller and a Hydronic Controller on the same Nexus iQ platform means you see your entire heating and cooling system in one dashboard — no switching between apps, no blind spots.
Ducted Zoning
Standard ducted zoning is simpler than VRV, but that doesn’t mean it should run blind. Zone damper issues, compressor cycling problems, and energy waste are just as common — they’re just harder to see without monitoring.
- Zoning Expansion — controls up to 8 zones per module with motorised damper outputs.
- Nexus 8 Gateway — connects the zoning system to Nexus iQ for cloud monitoring.
- Universal Expansion 8 — for additional control points such as exhaust fans, fresh air dampers, and auxiliary heating.
- Room Controller — in-room touchscreen for occupants to control their zone.
- 10" Wall Controller — centralised control panel for the whole system.
- Nexus Link — cloud connectivity.
Even a straightforward ducted system benefits from knowing which zones are running, how long the compressor cycles, and whether the system is working efficiently.
The Right Products for Each Setup
The interactive selector above gives you the shortlist, but a bit more context helps when you’re briefing a specifier or talking to a partner. Here’s how the three setups differ in practice.
For Commercial / Luxury VRV/VRF
The bigger the VRV system, the more valuable deep monitoring becomes. A Nexus 32 anchors the larger sites; the Nexus 16 handles mid-sized floors and premium residences; the Nexus 8 suits smaller installations where capacity is modest but the expectation of control is still high. Pair whichever gateway you choose with a Nexus Link for cloud connectivity, and add Discreet Sensors or a Sensor Expansion when you need independent zone readings separate from the FCU internals.
For VRV + Hydronic Hybrid
The hybrid setup is where the Nexus platform really earns its keep. A VRV gateway handles the refrigerant side, the Hydronic Controller handles the water side, and the Universal Expansion fills in any gaps — pumps, solenoids, sensors, domestic hot water loops. Add a Nexus Geo if there’s a ground-source heat pump in the mix. Everything lands in the same Nexus iQ dashboard, so the building manager sees one system, not two.
For Ducted Zoning
Ducted zoning is the simplest of the three, but the biggest payoff often comes from fixing the small stuff — a damper stuck half open, a compressor short-cycling, a zone that never quite reaches setpoint. The Zoning Expansion drives the dampers, the Nexus 8 brings the system into the cloud, and a Universal Expansion picks up anything else you want to control (exhaust fans, fresh air, auxiliary heating).
Want to see how this all connects?
Book a free demo and see Nexus iQ managing a real multi-system building.
Book a DemoWhat About Mixed-Use Buildings?
Some buildings combine all three — a commercial ground floor with VRV, residential upper floors with ducted zoning, and a shared hydronic heating loop. Nexus iQ handles this by connecting multiple controllers to a single cloud platform. One dashboard for the entire building, regardless of how many different system types are running underneath.
Here’s what that might look like in practice for a typical six-storey mixed-use development:
The building manager logs into one platform and sees retail, office, residential, and plant room data in the same view. No separate apps, no cross-referencing between vendors, no blind spots between disciplines.
Sizing Guide: How Many Gateways Do You Need?
VRV sizing is the question that comes up most often. This reference table keeps it simple — count your FCUs, then pick the gateway (or gateways) that cover them.
| Indoor Units | Recommended Gateway |
|---|---|
| 1–8 FCUs | Nexus 8 |
| 9–16 FCUs | Nexus 16 |
| 17–32 FCUs | Nexus 32 |
| 33–64 FCUs | 2 × Nexus 32 |
| 65+ FCUs | Multiple Nexus 32 (contact us for design) |
Each gateway connects to Nexus iQ independently, so scaling up is just a matter of adding another unit. No software changes, no reconfiguration, no re-licensing headaches.
The Real Cost: BMS vs Nexus iQ
Traditional Building Management Systems charge per control point — every sensor, every switch, every reading. For VRF systems, each indoor unit typically needs 4–6 BMS points (on/off, mode, setpoint, room temp, fault, fan speed). That adds up fast. Nexus iQ connects directly to the VRF communication bus — one gateway handles all units with zero per-point costs.
Drag the sliders to estimate the cost difference for your building. All figures are approximate — for an accurate quote, contact our team.
Traditional BMS
Nexus iQ
This calculator provides indicative estimates only for general comparison purposes. Actual BMS costs vary significantly based on system complexity, building type, integrator pricing, and project-specific requirements. Nexus iQ pricing shown is based on current list prices and may vary. Contact our team for an accurate site-specific quotation.
The Bottom Line
The right monitoring setup depends on your system, not a one-size-fits-all solution. A luxury home with VRV and underfloor heating needs different products than a retail strip with basic ducted zoning. The good news is the Nexus platform is modular — start with what you need, expand when you need more, and see everything from one place.
If you’ve got a mixed-use build, don’t panic about complexity. The point of the Nexus ecosystem is that every product talks to the same cloud, so adding another gateway or another expansion module doesn’t create another silo — it just adds to the same dashboard.
Not Sure Which Products Suit Your Project?
Talk to an Airnexus partner. They’ll assess your system, look at your drawings or specs, and recommend exactly what you need for the building in front of you — no obligation, no pressure, no up-selling products you don’t need.