Did you know that an air handler – also named HVAC (Heating Ventilation and Air-Conditioning) – is one of the most complex items of factory equipment to master? This self-regulating system is sometimes likened to a “black box” and it is no easy task to gauge its energy performances. And yet, with the right tools, your teams are perfectly capable of optimising them, so don’t let this opportunity pass you by.
This is why it is essential to have a line-of-business web application for monitoring and optimising your air handling units’ energy consumption. HVAC are used to achieve stringent air quality levels in workshops (dust, humidity, temperature, etc.). They are made up of numerous pieces of equipment that automatically check a variety of air parameters (mainly temperature, hygrometry and pressure). There are so many of these parameters that pinpointing losses or off-target results is a very complex task. As a result, malfunctions often go undetected! On top of this, the teams do not all have the same experience and operating practices, so they do not zero in on the same issues. Sound energy management will lead to greater efficiency on the ground.
Air handling units: complex or systemic?
HVAC are not completely unfamiliar, of course. However their operation depends on a “thermodynamic air path” that determines the successive conditioning operations to be carried out on the outdoor and/or indoor air to bring it to the desired quality at the air delivery point.
“The steps are simple – heating, cooling, cleaning, etc. – but they are all linked and work together to adjust the air parameters in a fully coordinated manner. The cooling batteries are used to cool or remove humidity, while the cleaners can also humidify. HVAC can obtain the same results using different methods, so the difficulty lies in stabilising the most efficient configuration”, explains Stéphanie Hoarau, energy efficiency project manager.
Always something to tweak
You might think that, once an HVAC had been correctly configured, it would reach then efficiently maintain its objectives. But there are inevitably other factors to take into account, such as blocked or leaking valves, errors in the set values or in data entry, not to mention exogenous events such as variations in outdoor conditions or in the workshop itself.
“The problem stems from the fact that an HVAC is “target-oriented”. In other words, it tries to achieve the set value and may actually do so, even in failure mode, but at the cost of energy efficiency. Should an anomaly be detected through its interfaces, the operators still have to distinguish between the cause and the symptoms. Hot, dry air, for example, has to be humidified then cooled. If the air is too cool when it is injected, perhaps because a valve is too open, upstream heating coils will be able to intervene to correct it. It’s not easy to diagnose this sort of problem at a glance from the supervision unit!” says Stéphanie Hoarau.
Data to the rescue!
So how can you assess what is really happening in your HVAC? By collecting a maximum of data about its operation, including (and even especially) its subsystems.
“Based on the technical features of all of an HVAC’s components, we can build a theoretical operating model and bank of situations, combining the input data (such as the outdoor conditions and the set values) and the precise state of the subsystems: a set value for a specific valve, the temperature after a specific item of equipment, etc. We can then compare it with the actual, real-time situation to scan for any inconsistencies and raise the alarm in the event of non-standard results,” says Stéphanie Hoarau.
The benefits to be gained by monitoring HVAC’ energy performance
The potential gains are significant because they put an end to persistent problem situations:
- they avoid over-consumption;
- they improve air quality;
- they reduce maintenance costs, because less time is spent operating in downgraded mode (when an item of equipment is not working properly, the neighbouring equipment tries to compensate for the fact).
Blu.e’s HVAC application is already operational. Operators can see at a glance everything that is happening in your HVAC and solve “undetected” problems before they show up. So, ready to open this “black box”?