HVAC controls and BMS, from audit to servicing
Elyos Building Automation is an HVAC controls and BMS integrator, based in Anderlecht, Brussels, since 2017. We audit, install, program and service the controls of heating, ventilation and air conditioning, from stand-alone controllers to full building management systems, in commercial buildings and apartment blocks. We work for HVAC contractors, MEP consultants and building managers across Brussels, Wallonia and Flanders. [to confirm]
How controls drift over the years
Controls set up well on commissioning day do not stay that way on their own. Occupancy changes, a part gets replaced, a setting is changed in a hurry, and nobody looks at the whole system again. The same drift turns up from one building to the next:
Schedules. The heating runs at weekends and through the holidays, because the time programmes never followed how the building is really used.
Setpoints. A setpoint raised ‘just to see’ after a complaint, and never brought back down.
Sensors. An outdoor sensor in full sun or a badly placed room sensor, and the whole compensation curve shifts.
Valves and actuators. A seized valve or an actuator left in manual, and the circuit no longer follows demand.
Alarms. Alarms acknowledged every morning, without anyone looking for the cause.
Comfort complaints. Too hot on the south side, too cold on the north, while the boiler keeps running.
You rarely see this drift on a screen. You see it on the energy bill and in the occupants’ emails.
Auditing your existing controls
We start by looking at what is really there: in the plant room, in the control panels and on the supervision system, if there is one.
We record:
- the controllers: brand, generation, state of the program;
- schedules, setpoints and the compensation curve of each circuit;
- the condition of sensors, valves and actuators;
- active alarms and their history;
- the points brought back to the supervision system, and the ones missing;
- the heating and cooling power, which tells you whether the BACS regulation applies to the building.
You receive a clear assessment and a list of priorities: what an adjustment fixes, what needs a part, what needs replacing. [to confirm]
Installation: control panels, sensors, actuators, meters
We install and wire the control equipment: control panels and controllers, temperature sensors, valve and damper actuators, energy meters. On new builds and refurbishments alike, we work on our own or alongside your HVAC contractor: they keep the heating or ventilation package, we take the controls.
Before work starts, we put in writing who supplies the equipment, who wires it, who programs it and who commissions it. [to confirm]
HVAC contractor or MEP consultant? See how we take on the controls package
Programming and commissioning
We program the controllers and the BMS supervision: heating and cooling sequences, compensation curves, time schedules by zone, alarms, metering. Then we commission point by point: every sensor is read, every valve and actuator is driven on site, and every alarm is triggered once to check that it comes through.
At handover you receive up-to-date documentation: the points list, a backup of the program, the wiring diagrams and the settings. Whoever works on the system after us will know what was done, and why. [to confirm]
Troubleshooting and ongoing support
An alarm, a comfort complaint, a breakdown: we come on site, or connect remotely when the installation has secure remote access. A schedule, a setpoint or an alarm can often be dealt with without a visit. A sensor or an actuator cannot.
After the call-out, we can keep an eye on the installation over time: alarm reviews, seasonal adjustments, fine-tuning after a complaint. [to confirm]
We work for businesses and building managers, not for private households.
Taking over an existing system
The previous contractor has gone, nobody has a backup of the program, and the supervision screen shows alarms that no one understands any more. Or the building mixes several brands, installed at different times. We take these systems over.
Something missing? That does not stop us. Without a backup, a program cannot always be read back from the controller, and then it has to be rebuilt from what the installation does. We tell you at the audit stage.
To get started, send us what you have:
- a photo of the label on each controller, showing its brand and reference;
- a photo of the control panel with the door open;
- the wiring diagrams, if they exist;
- the program backup and the software licences, if you have them;
- the workstation or web address of the supervision system, if there is one;
- a list of recent complaints and alarms.
BMS and BACS: what is the difference?
BMS
building management system
The building’s controllers linked to one supervision system. You see temperatures, equipment states and alarms, and you change schedules and setpoints. Also called a building automation system (BAS).
BACS
building automation and control system
The system Belgium’s regional rules require in larger non-residential buildings. It is not a product but a set of functions: monitoring and logging energy use, detecting losses of efficiency, and communicating with the building’s other equipment. Above 290 kW of heating or air conditioning, a non-residential building must have one.
An existing BMS can meet the BACS requirements if it does these things. It is one of the points we check during an audit.
Check your BACS obligationLast checked: 9 November 2026
Frequently asked questions
What does a BMS do?
A building management system links the controllers of the heating, ventilation and air conditioning to one supervision system. It runs the time schedules and setpoints, shows temperatures and equipment states, raises alarms and logs energy use. A well-set BMS heats and cools the building when it is occupied, and tells someone when something drifts.
How much does a BMS cost?
The price depends mostly on the number of points to connect (sensors, valves, alarms, meters), the number of controllers and control panels, the state of the existing installation, the supervision software and its licences, and the days of programming and commissioning. [to confirm] To give you an answer, we need the building type, the installed power and a few photos of the control panels.
What types of HVAC control are there?
First, by what they control: heat or cooling production (boilers, heat pumps, chillers), distribution (circuits, valves, pumps) and the rooms themselves (by zone or by room). Then by how they control it: from the outdoor temperature with a compensation curve, from the room temperature, by time schedule, or by air quality for ventilation. A stand-alone controller runs one circuit or one air handling unit. Controllers linked to a BMS run the whole building.
Can you take over a system from another brand?
Yes. We take over installations put in by others, on the systems we program: Siemens Synco and Desigo, Distech Controls, Priva, Honeywell Trend and KNX. [to confirm] For any other system, send us the controller reference and we will tell you whether we can take it over or whether it is better replaced.
Can you work remotely?
Yes, when the installation has secure remote access, through the supervision system or directly on the controller. We can then read alarms and correct a schedule or a setpoint without a visit. If there is no access, we can set it up with whoever runs your IT network. [to confirm] A sensor, a valve or an actuator always needs a visit.
A system to audit, take over or troubleshoot?
Tell us about the building and what is going wrong, and we will get back to you to arrange a meeting.