Cloud HVAC programmes still need a wall face that occupants will actually use. A generic Wi-Fi thermostat under your logo rarely survives an RFQ. An OEM Wi-Fi MQTT room unit is the other path: a branded, host-driven Room Unit that already speaks 2.4 GHz Wi-Fi and, for authorised partners, MQTT or REST — alongside Modbus on the copper pair.

Alledio’s Room Unit is that class of device. It is designed and manufactured in Slovenia for HVAC original equipment manufacturers. The host or the cloud still owns control. The wall unit is the face, the sensors, and the connected endpoint.

Who this is for

This article is for OEM product managers, cloud-platform owners, and BMS device makers who need a branded wall interface that can sit on Wi-Fi and MQTT, not only on a copper pair.

Typical applications map to real OEM lines: air handling units, residential and commercial heat pumps, VAV and rooftop units, ductless mini-splits, VRV, chillers, boilers and DHW, plus actuator-facing UIs. End markets include offices, schools, hotels and museums. Installers and system integrators cannot buy Alledio direct. The commercial model is high-MOQ OEM (the site cites an order of magnitude around 5,000 units). A sample is an NDA conversation, not a webshop.

If you need standalone I/O and application logic in the same family, that is the Room Controller, not this SKU. Keep that split in the RFQ so purchasing does not mix a display with a controller. For the RS-485-first version of the same hardware, see the live OEM Modbus Room Unit post.

Wi-Fi and MQTT as a partner option

An OEM Wi-Fi MQTT room unit is not a retail thermostat SKU and not a public broker you can subscribe to from a catalogue. On the Room Unit, Wi-Fi 2.4 GHz (STA/AP) is how the device joins a network, receives OTA firmware, and talks HTTPS. MQTT and REST sit behind that radio for authorised partners. Credentials are issued after verification. That is a partner option, not a “native MQTT” catalogue SKU.

MQTT is a publish/subscribe protocol. In this architecture the wall unit can publish sensor values and occupant requests; the host or the cloud decides what those messages mean for the plant. REST is the request/response counterpart for the same partner programme. Neither path moves safeties onto the glass.

Modbus RTU on RS-485 remains the default copper citizen. Wi-Fi does not replace the bus. A heat-pump indoor unit that already has a slave map can keep that map and add a connected SKU for programmes that want OTA, a partner cloud, or a commissioning path that does not start with a USB cable.

Bluetooth 5 LE is ready. The GATT map is yours. Commissioning over BLE is a client specification, not a consumer app-store listing. Write the services you need in the RFQ if field teams will pair a handset to the wall unit before the 2.4 GHz radio joins the site SSID.

Host vs cloud: who publishes setpoints

The wall device shows temperature and humidity, takes a setpoint, exposes fan speed or Auto, can hold a weekly schedule, and can surface notifications. Recuperation views or a sanitary hot-water shortcut are firmware options, but they are still requests to a host unless you specified the Room Controller.

On a cloud-connected heat pump, the outdoor unit and hydronic logic stay on your controller or in your cloud; the wall unit publishes occupancy, setpoint, and sensor values. On an AHU line, the board already certified for safeties keeps supply-air limits, frost, and fire-mode. On a fan-coil or VAV box, fan and damper commands still leave your host, even if the occupant only ever touches the glass.

That split is the point. You keep control IP. Occupants get a 3.5" panel that feels like your brand. Wi-Fi is for OTA and, for verified partners, MQTT or REST. BLE is ready for commissioning. None of that puts the plant in the wall.

Write the host contract in one page: which topics or registers are read-only sensors, which are writable setpoints, and which bits are alarms. If the wall unit can enter an unoccupied or boost state, say whether that is a local timer or a request the host or the cloud must honour. Ambiguity here is how field teams later “fix” a unit by writing plant logic into a display.

Why a 3.5 inch OEM HVAC touch panel belongs on a cloud line

A 3.5 inch OEM HVAC touch panel is large enough for temperature, humidity, air quality and a one-tap absence, and small enough to stay in a 98 mm square. Capacitive touch plus a brightness sensor keeps the glass readable in a lobby and quiet in a bedroom.

Colourways (white, black, silver, plus custom) let the same electronics follow a hotel, school or heat-pump indoor line. OEM customisation covers logo, UI, widgets, hardware and firmware. You pay for the delta, not for reinventing a certified radio and a mould.

Flush depth matters as much as the glass. That is an OEM wall UI flush mount in a 98 × 98 × 23 mm, IP20 housing — not a surface brick. Power is 12–42 V DC (24 V recommended) or 24 VAC ±25%. Do not assume 230 VAC. That is the thermostat family.

The same 3.5" panel can carry a wired SKU and a connected SKU if the brand surfaces and the topic map are written as separate lines in the RFQ. Hotels usually care about the glass and the colourway first. Heat-pump and AHU brands usually care about the host contract and the cloud topics first.

The Room Unit was on the floor at Andivi at MCE Milano 2026 as a branded HVAC wall UI, not a DIY thermostat. How the room feels, not only how the glass looks, is also the thread of Beyond design: it’s how it feels.

How to write the RFQ for an OEM Wi-Fi MQTT room unit

Buyers lose months when the RFQ mixes “pretty thermostat,” “cloud thermostat,” and “IAQ sensor.” Use language the factory can quote, and attach the mechanical drawing with the ICD.

Ask for:

• Wi-Fi 2.4 GHz (STA/AP), OTA, HTTPS; MQTT and REST for authorised partners, with credentials after verification.
• Host-driven architecture: setpoints, fan, schedule and alarms on the glass; plant algorithms on your board or in your cloud.
• Default T/RH, with optional VOC, CO2 (400–5000 ppm), pressure and presence as orderable variants.
• Power that matches your wall: 12–42 V DC (24 V recommended) or 24 VAC ±25%. Do not assume 230 VAC.
• A 98 × 98 × 23 mm, IP20 housing, 3.5" capacitive LCD (480 × 320), ABS plus scratch-resistant glass.
• Bluetooth 5 LE ready, with the GATT map supplied by you if BLE commissioning is in scope.
• Branding scope: exterior logo, UI colours, widgets, firmware, and whether the connected SKU ships beside a Modbus SKU.
• Compliance you can defend: RED 2014/53/EU including the cybersecurity delegated act, RoHS, and a 10-year security-update window.

State MOQ, sample count, NRE for firmware, who owns the topic map (and the Modbus register map if both paths ship), and who issues partner credentials. Ask for termination as a software setting on the copper SKU, not a field modification. Specify the SSID class, whether STA or AP is the commissioning default, and who holds the HTTPS and MQTT credentials after the NDA.

Also name the documents you want back: ICD, topic or register list, mechanical drawing, and a short integration note for your cloud team. That pack is what turns a pretty glass into a line item your plant firmware or your broker can use.

Product proof

On the Room Unit: Modbus RTU over RS-485 (slave default; master on request); Wi-Fi 2.4 GHz (STA/AP), OTA, HTTPS; Bluetooth 5 LE per client spec; REST and MQTT for authorised partners. The product page also lists a 0–10 V analogue output as a connectivity option.

Not a catalogue SKU here: native BACnet on this product (native BACnet lives on the Multi-Sensor family); KNX; 230 VAC relays (Thermostat / Room Controller); a public MQTT broker.

If the RFQ says “BACnet wall UI,” do not force this SKU. Budget an OEM protocol add-on, or use the Multi-Sensor for field sensing and keep the Room Unit as the occupant display. If the RFQ says KNX, treat that as a separate firmware or hardware quote, not as a hidden checkbox on this page.

Those numbers are what you can put in a customer PDF today. Confirm any cell you cannot see on the current datasheet before you lock an RFQ. Comfort copy on the site is specific: the unit manages how the room feels (setpoint, fan, schedule, humidity and air-quality visibility) while the host, the cloud, and the plant do the energy work.

FAQ

Can an installer or systems integrator buy one from a webshop?
No. Alledio sells to OEMs. Installers and SIs get devices through the OEM’s channel. OEMs ask for a sample under NDA.

Does the Room Unit run the plant in the wall?
No. It is host-driven. Sequences and safeties live on your controller or in your cloud unless you specified the Room Controller.

Is there a KNX catalogue SKU?
KNX is not listed as a shipping protocol on alledio.com. Other buses are OEM firmware or hardware work, quoted separately.

Is MQTT native on the Room Unit?
MQTT and REST are supported for authorised partners after verification. That is not a public broker SKU and not an open topic anyone can subscribe to.

Who publishes setpoints?
The occupant can request a setpoint on the glass. The host or the cloud owns control and publishes the value the plant will honour.

What power does the Room Unit take?
12–42 V DC (24 V recommended) or 24 VAC ±25%. Not 230 VAC (that is the thermostat family).

What to do next

Start on the Alledio Room Unit page, then open an OEM conversation for logo, UI, firmware, MQTT credentials and samples. Bring SSID class, power, sensor options, MOQ, and whether the connected SKU ships beside Modbus. That is the shortest path from an RFQ sentence to a wall UI that already speaks Wi-Fi and MQTT.