The Aircon Was Always the One Thing Your Smart Home Couldn't Talk To. That's Changing.

Every KNX home I've ever wired has had one appliance sitting outside the system, blinking at you with its own remote, running its own schedule, answering to nobody. Nine times out of ten, it's the air conditioner.

That's not because integrators didn't want to touch it. Most split-unit ACs were never built to be touched. They talk infrared to their own remote and nothing else, no open protocol, no group address, no place on the bus. You could automate every light, blind and geyser in the house and the aircon in the main bedroom would still be a dumb island, controlled by whoever could find the remote down the side of the couch.

That gap has quietly closed. It's worth explaining properly, because it changes what "fully integrated" can mean for a home that already has AC units installed.

What changed

KNX Association published a rundown of current HVAC hardware back in June, and the piece that stood out wasn't a new thermostat. It was a universal IR-to-KNX gateway. The idea is simple: the gateway sits on your KNX bus like any other device, but on the other side it speaks infrared to whatever AC unit is already on your wall. Intesis is the name most integrators will recognise here. Its gateway's auto-learn function reads your unit's own remote and captures its command set, so it doesn't matter which brand you're running.

There's a second route, and it's arguably the cleaner one where the AC brand supports it: a direct wired gateway instead of an IR one. Airzone's Aidoo KNX connects straight into an inverter or VRF unit's own communication port rather than mimicking a remote over infrared. It's more limited in which brands it talks to, since it needs the manufacturer's protocol on the other end, but the payoff is a proper wired link with confirmed actions, real status feedback and error detection, no line-of-sight IR blaster required. Airzone also sells a separate gateway for bringing its own multi-zone ducted systems onto a KNX bus, configured from ETS like any other device.

Here's the part that matters for automation rather than just remote control: both routes report state back to the bus instead of only sending commands. Older IR bridges could only blast commands outward and hope. They had no idea if the unit was actually on, what mode it was in, or what temperature it was set to. A bidirectional gateway, wired or IR, means your system knows the aircon's real status instead of guessing. That's the gap between "turn everything off when I leave" working every time and working most of the time.

Once that link exists, the aircon stops being an island. It can switch off when a window contact opens, drop to standby after a room's sat empty for twenty minutes, or sit inside the same leaving-the-house scene as the lighting and blinds instead of needing its own remote hunted down separately. Some of these gateways also carry KNX Data Secure encryption, which matters because the gateway is effectively a new entry point onto the bus and shouldn't be left wide open just because it's talking to a nine-year-old wall unit.

The other half: floors and radiators, not just air

The same shift has happened on the water side of climate control. Underfloor heating and cooling loops used to need a separate actuator box, a separate temperature sensor, and separate wiring for each. Newer valve actuators fold the controller, the sensor and the encryption into one device that powers directly off the KNX bus, with no extra box hanging in the manifold cupboard. It's a smaller story than the aircon one, but it's the same pattern: hardware that used to sit just outside the bus is being pulled onto it properly.

Why it matters for a brief

I've had this conversation with clients before: they've already got good aircon units installed, sometimes recently, and don't want to rip them out just to get them into the automation system. Fair enough. That used to mean living with a gap in the system on principle. It doesn't anymore. Put a gateway on the bus, keep the AC unit that already works, and the loop closes without touching the unit itself.

For Joburg specifically, this matters more than it would somewhere with central ducted air. Most homes here run on split units, added room by room over years as budgets allowed. That's exactly the messy, mixed-brand situation a universal gateway is built for. It doesn't care that the study's unit is five years older than the one in the main bedroom.

If you're specifying a system now, ask your integrator three things at brief stage: which rooms actually need a gateway, whether the units already installed support a direct wired connection (Airzone-style) or only IR, and whether that IR option gives you two-way feedback or just blind commands. Sort that out before wiring goes in and it's a five-minute conversation, not a retrofit headache later.

The aircon doesn't have to be the one thing your smart home can't see. It just needs the right device sitting between it and the bus.

Just a conversation about what the project needs.

wayne@knxlogic.co.za | 082 564 3982 | www.knxlogic.co.za