Why is it important to have the right air regulation?

Bratislava, 24 February 2021
Author: Michal Gorný, Project Manager ENGIE Services

In the current period of coronary crisis, tenants are increasingly reassessing the size of rented office space. In particular, the number of employees who have been left to work from home from day to day is changing the trends in the industry. Companies will therefore be more careful when choosing the size of leased space in the near future, and pressure on the quality of the space will certainly increase. One of the important aspects that have an impact on the quality of the indoor environment is the properly designed and regulated HVAC system in the building. The quantity and quality of air in offices affects the well-being and comfort of the tenants and will therefore be an important criterion when selecting leased space.

What is air handling and where is it used?

The air handling system is a complex system that serves for the treatment and distribution of air in the building premises. It consists of an air handling unit and ductwork that distributes the air in the building. The HVAC system includes air conditioning, which is used to treat the incoming air by filtration, dehumidification/humidification and thermal treatment (heating/cooling). Anecdotally, the term air conditioning is sometimes confused with indoor cooling units (Split, Multisplit , VRV and fan coil). These devices are used to cool the space in summer and heat it to the desired temperature in winter. The units work with, and filter, circulated air.

  /> Compared to conventional ventilation, air handling ensures much more efficient air exchange. It brings air continuously into the building space without noticeable draughts and provides heat recovery, thus reducing the energy consumption of ventilation. In addition, it enables set and desired ambient parameters such as temperature, cleanliness and humidity to be achieved. Air handling units are mainly used in high-rise office buildings, shopping malls or some industrial halls. There are several reasons why high-rise buildings are currently being designed without the possibility of opening windows: <ul> <li>uniformity of air exchange, minimization of draughts and the associated discomfort of tenants, better light transmission, better view, easier maintenance and last but not least lower costs associated with the acquisition of windows.</li> </ul> </li> However, it is also possible to provide natural ventilation in high-rise buildings. These are mainly modern buildings that have been designed and built with a double glazed façade, thanks to which ventilation does not lead to the so-called chimney effect (very strong draughts). However, despite this advantage, for reasons of operational efficiency, most buildings use air conditioning instead of ventilation.  <strong>How does air handling in buildings work?</strong> It is important for the functionality of any installation that it is well tuned. And the same applies to buildings. To function properly, they need to be well tuned - that is, regulated. In practice, we encounter two types of HVAC tuning - in new buildings and in existing buildings.  <strong>Inspection and adjustment of HVAC in new buildings</strong> Construction is a complex project in which different professions work closely together, including HVAC design and implementation. The designer, based on information about the use and occupancy of the space, will design the HVAC solution for the building, which includes - HVAC units, HVAC ductwork (piping), controls and terminal elements. The designer will also determine the capacity of the HVAC units and how much air will flow to each unit and room in the building.  After the design and development of the project is followed by the implementation, which includes the installation of all parts of the HVAC system, ductwork, system recovery - measurement and regulation (MaR), its start-up and regulation.  The HVAC units and the designated sections are measured and regulated in accordance with the documents provided by the designer. It is then necessary to check whether the HVAC system meets the specified parameters and whether it supplies the amount of air to the individual rooms in the building as designed by the designer. Finally, a measurement and adjustment report is prepared and the building can be commissioned.  If everything is done in accordance with the designer's design, the building operator can ensure the desired comfort for its tenants thanks to the correct air supply. Unfortunately, it is not infrequently the case that in the final phase the HVAC system is not regulated or the documentation of this performance is lost. In the future, the building owner will have no choice but to re-regulate the entire building if necessary without the relevant documentation.  <strong>Inspection and adjustment of HVAC in existing buildings and plants</strong> A building is like a living organism. Its operations and layouts change over time. It is often forgotten that the air distribution systems also need to be adjusted and regulated according to the changes.  Whether the layout of the building has been changed or the original condition has been maintained, we know from experience that tenants quite often complain about the quality and lack of air. What options does the operator have to deal with this situation? <ul> <li>Satisfied tenants can confirm the correct functioning of the HVAC system on the basis of an alignment report at the handover of the building. However, the building operator can only do this if the air distribution in the building has not changed due to its layout.</li> <li> <li>The operator will check the actual situation by measurement and, if necessary, implement a system readjustment.</li> <li>If there are documents on the amount of air required for the individual sections of the building, it is sufficient to measure the amount of supplied air, compare it with the design value and adjust the system accordingly.</li> <li>If the documents do not exist or are invalid due to a change in the layout of the interior spaces of the building, it is necessary to redesign the air distribution. In this case, the designer must familiarise himself with the new layout of the building, its use and the existing types of HVAC units. He/she will then create a new design, according to which the HVAC distribution will be adjusted. At the final stage, a valid adjustment report will again be issued to confirm the correct functioning of the system.</li> </ul> <strong><img style=obchod.sk@engie.com.

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