You may have already noticed that your workspace is equipped with many systems and technologies that work in the background to ensure you have a comfortable and secure working environment. But have you ever thought about what's hiding under your feet and above your heads?
This article gives you visibility into the invisible elements that shape your daily life in the office. We're going to take you behind the scenes of the technology that makes modern offices so powerful.
We will focus on the most common office systems: HVAC-S, electrical, and fire safety. These essentials are often forgotten, but they play a crucial role in creating a safe and efficient work environment.
You've probably heard of HVAC before, but what is this abbreviation? These are simply the terms Heating, Ventilation and Air-Conditioning. The letter "S" for Sanitary is regularly associated.
When talking about heating and cooling, common concerns often relate to the wrong temperature, whether it's too cold in the winter or too hot in the summer. To better understand the causes of this dissatisfaction, it is essential to consider the theoretical principles that govern the operation of heating and cooling systems.
A complex empirical formula known as the Fanger model is used to calculate the PMV (predicted mean vote = predicted average vote of thermal comfort), based on the following values:
- Thermometer global temperature (°C)
- Radiation temperature (°C)
- Air temperature (°C)
- Air humidity (%)
- Air velocity (m/s)
- Activity: Met Value (-)
- Clothing: clo value (-)
As a general guideline, the value ranges between -3 and +3, with zero representing the neutral point of optimal comfort. The PPD (predicted percentage dissatisfied) reflects the percentage of individuals who are dissatisfied with the room's climate and is derived from a calculation. A PPD of less than 5% corresponds to a PMV of 0, indicating optimal thermal comfort. Statistically speaking, even under ideal climatic conditions, it is still possible for 5% of individuals to express dissatisfaction!
These calculations are based on data from scientific studies carried out in the 80s with people who were asked to subjectively assess their comfort under various experimental climatic conditions. These results have given rise to the SN EN ISO 7730 standard (see SN 520 180).
Let's move from principles to practice. How do office heating systems operate?
Many buildings in Luxembourg are equipped with active ceilings with 1200x600mm metal slabs, which rest on bandrasters (see photo below). These ceilings are less and less installed today, because other systems exist with a much more careful design, and superior climatic performance.
In 2025, the trend is to integrate heating and air conditioning into a single ceiling, whether through suspended islands, or slatted ceilings such as the CBRE House building. These systems combine heating/cooling power and aesthetics that provide customers with a comfortable and stylish system.
Did you know that in each slat, there is a plastic pipe in which water circulates, and thus allows temperatures to be maintained at 21°C as a setpoint, whether it is -12°C or 32°C outside?
In any case, it is important to keep in mind that all these systems are supplied with water, which often circulates above your PC, or under your office chair.
Thanks to the thermostats, building control systems can now measure temperature in real time and adjust water flow accordingly, delivering precisely the energy needed to achieve the desired temperature. This marks a significant departure from the days of radiators operating at full capacity alongside cold active panels running at maximum power.
Have you ever wondered how your refrigerator works? It is easy to imagine a boiler burning gas, wood or oil to produce heat, but how do we make it cold? Melting ice cubes is one solution, but in terms of logistics, we know how to make it simpler.
Without going into complex explanations, the process of refrigeration manufacturing follows a relatively constant principle. To reduce the temperature of a space, we pull calories out of the air, which we move to another place. Basically, we take the heat, and we evacuate it. That's why your fridge heats up, the calories come from the inside, they are then rejected in your kitchen. It is exactly the same principle for office refrigeration machines.
Machines contain what is called a heat transfer gas (there has been an important debate about these polluting gases for several years. Today, manufacturers are moving towards solutions using emission-free gases, capable of moving calories to extract heat from the offices and reject it outside. Fortunately, we are now able to reuse this heat to recycle it for other uses (hygienic air drying, preheating domestic hot water, etc.). Here is a diagram illustrating the refrigeration cycle:
Ventilation is a crucial part of the office air conditioning system. They are connected to what is generally called an AHU, which stands for Air Handling Unit. These are the large machines, often installed on the roof or in the top level of buildings. The objective is simple: to suck in outside air, filter it, heat it or cool it, and blow it into the offices to bring in fresh treated air. Parallel ducts are used to suck in polluted air (this is the air exhaled by employees, loaded with CO2), and release it outside the building. When a single machine can carry out this exchange, then it is called double-flow ventilation. Below the diagram of the CTA present on the roof of CBRE House, with a total length of 7.29m:
These ventilation ducts cross the entire height of the buildings, and then circulate in the false ceilings, or in the false floors.
The new generations of power plants are equipped with very high-efficiency heat exchangers, capable of recovering more than 85% of the calories contained in the exhaust air. This results in significant energy savings compared to machines from previous decades.
Finally, even if domestic water remains very easy to understand, we can note that more and more buildings are equipped with leak detection systems, in particular composed of automatic valves controlled by presence detection. In other words, when you enter the toilet, the presence detector connected to the lighting sends a command to open the valve, thus allowing the flushes to be filled and the water to be supplied to the taps. Without presence, no leakage can occur.
Electricity CFO (High Current)-CFA (Low Current)
Let's take the example of a building of +/- 4000m², do you know how many meters of cables are present? We easily exceed ten kilometers. But what are they for, and where are they?
Electricity is a complex field that encompasses several distinct aspects, including high and low current.
The high current represents in a simplified way the electricity that we think of in the first place, i.e. power sockets, lighting, etc. Low current is the current that allows information to be transported in the form of a signal (access control, fire detection, regulation, internet network, etc.).
It is quite simple to imagine all the cables that run through the ceiling for lighting, but you also must think about the rest: presence detectors, Wi-Fi terminals, fire detectors, blind management modules, emergency lighting. It is also important to be aware that many cables are necessary to control or supervise HVAC equipment (fire dampers, control valves, air flow dampers, sanitary solenoid valve). Imagine also that for each workstation, a cable runs along a raised floor to the IT room.
The purpose of these explanations is to raise awareness that each visible element actually hides a multitude of other hidden elements, which are often underestimated but essential to the safety and operation of buildings.
It is important to address fire-fighting devices, especially the sprinkler system, which is an essential element for building safety. Sprinkler heads, those small devices visible under the false ceiling, are probably familiar, but what really happens when a fire breaks out?
The head is equipped with a heat-sensitive glass bulb, which breaks at 68°C. When it breaks, the pressure in the pipe is released, extinguishing the fire. The pumps then resume their function to maintain pressure and water supply. This essential safety device ensures a high level of safety, allowing for quick and trouble-free evacuation.
In this article, we've explored the technical foundations of workspace design, delving into the unseen elements that shape our work environment. From heating and air conditioning to ventilation and fire safety, we've examined the essential components that make modern offices comfortable and secure. By prioritizing the technical foundations of workspace design, we can create built environments that support the well-being of occupants and contribute to a more sustainable future.
Key Takeaways
- Understanding the technical aspects of workspace design is crucial for creating comfortable and efficient work environments.
- Heating, ventilation, and fire safety systems are critical components of modern office design.
- Innovative and environmentally friendly solutions are becoming increasingly important in office design.
