When stadiums were first developed, their focus was to provide an enclosure for athletes’ play, with little attention being given to the spectators. These facilities have evolved in the last few decades with stadiums becoming more than just facilities for organized sport; they now offer a gathering place for people with shared interests and provide economic benefits to the surrounding community. This evolution has benefited from advancements in architecture and engineering.
The new stadiums are often mixed-use, iconic, and fan-centric, but are also corporate enough to turn a match day profit. New spectacular designs have enhanced the spectator experience. Innovation has occurred inside the stadium too, as arenas have started offering entertainment spaces and activities that people can enjoy before the match, including on non-game days.
This evolution has not only affected architectural design in stadiums, but also HVAC design, as the more modern these facilities have become, the more they have started to integrate building services.
HVAC systems are essential services of modern buildings as they are needed to meet occupant comfort expectations, especially in facilities that offer experiences.
Thermal comfort in buildings such as stadiums is very relevant. HVAC systems can be important allies in the design of a comfortableexperience for spectators and other occupants.
HVAC systems, though, can also have a significant impact on operating costs and consequently on profits. For this reason, there are aspects that are worth considering when designing HVAC systems for stadiums.
Thermal comfort and indoor air quality
As mentioned, modern stadiums are increasingly mixed-use facilities that include shopping areas, bars, restaurants, VIP lounges, and sky box areas. All of these aim to offer spectators a premium experience before, during, and after the game – as well as on non-game days. Of course, a premium experience cannot be separated from thermal comfort, which needs to be guaranteed in all those areas in every season, as stadiums are no longer simply sports facilities, but also accommodate corporate meetings, events, concerts, and shows all year round.
Comfort cooling and heating are then required in these facilities, and, depending on the need, chillers and/or heat pumps that are properly sized and can meet the cooling and heating demand of the different areas of the stadium are needed.
The same goes for indoor air quality (IAQ), which is another very important aspect to consider, as the multitude of people in the different areas of the stadium deserve to breathe clean air.
That is one of the aims of well-designed ventilation systems, which are great tools to clean air in indoor environments through air-exchange and air filtration.
Another interesting aspect that Daikin focuses on is IAQ monitoring, as monitoring and tracking is fundamental to being able to act and make improvements.
By integrating the Daikin IEQ sensor, the HVAC system benefits from an indoor environmental quality (IEQ) sensor that monitors and tracks indoor conditions through a set of indoor air quality parameters giving facility managers a clear indication of the indoor air quality status in the building they manage.
While indoor cooling and heating are nothing new, we have recently seen air-conditioned stands and pitches in stadiums. This has been increasing in the last few years, especially in countries where extreme heat makes air conditioning necessary for people to normally gather and engage in activities without any harm to their health.
Think about stadiums where over 80,000 people gather in ambient conditions that are regularly over 40 °C – 80,000 bodies breathing in extreme heat, generating more heat and humidity, and making the environment unhealthy. That is not the image of a premium experience, plus it would be harmful for people.
HVAC systems can help avoid similar scenarios, helping to cool down seats and pitch areas in stadiums and providing the right amount of air exchange to guarantee the comfort and safety of both spectators and athletes.
Energy efficiency
Air-conditioning an entire stadium – especially when it does not have a retractable roof – might be considered detrimental from an energy consumption perspective.
However, there is another aspect to consider: life as we know it could not be possible in extreme heat without air-conditioning.
Once we have established that, we can analyse how modern HVAC systems can help to satisfy air-conditioning needs while still being energy efficient and environmentally sustainable.
For starters, HVAC systems should be considered to be an integral part of the building design aimed at achieving the best energy efficiency.
This means that aspects such as the:
- stadium orientation based on the sun’s movement
- building’s colour schemes and surface design aiming at reflecting heat and/or diverting winds
- presence of a retractable roof
- presence of photovoltaic panels to generate electricity that will power the stadium
should be considered before addressing the aspects that are more closely related to the HVAC system.
Just like the building design, the HVAC design must aim to achieve a very high level of energy efficiency, which can only be achieved by using a mix of advanced technologies that target every need that the project might present.
Inverter technology is vital for HVAC designs using air-cooled or water-cooled units, especially for buildings that present frequent variation in load demand based on occupancy and distribution of the occupants in different areas of the building.
In fact, by varying the frequency of the motor power supply, inverter technology modulates the compressor rotational speed (RPM) and in such a way controls the compressor capacity.
As the chillers and heat pumps installed in stadiums usually operate at part load, inverter technology is a valuable solution to increase their efficiency.
Then, to make the whole HVAC system more efficient, it is important that the water flow in the HVAC system can vary depending on the actual load demand of the building. A variable water flow system is the perfect solution, as it modulates the quantity of water flowing through the system and ensures that pumps work as efficiently as possible, reducing their energy consumption.
The same goes for air handling units (AHUs) that might be included in the HVAC system. Choosing models with high efficiency inverter fans and heat recovery can considerably reduce energy consumption.
Heat recovery, for instance, is an option that allow AHUs to recover heat from the exhausted air thanks to heat exchangers. These transmit heat from the stale air flow being ejected into the clean air flow being fed into the building, without any contamination between the two air streams. This process notably improves energy efficiency.
Another aspect to consider in complex HVAC systems is modularity. Modularity activates units based on the areas of the stadium that actually need cooling or heating in a certain moment, ensuring even more control over energy consumption. This can be achieved by splitting the load over a number of units that can be activated as required based on actual needs. The load of modern stadiums typically varies depending on the season or the specific event they are accommodating. This has a significant impact on the energy efficiency of the building. So, it is important to consider the variation in load demand for the entire building. For a more efficient HVAC system, it might be useful to split the load across multiple units of different sizes and control them as if they were a big single unit.