The COVID-19 pandemic fundamentally changed the way we think about indoor environments. Indoor Air Quality (IAQ) and ventilation suddenly became a public health priority, highlighting the crucial role buildings play in protecting the health and wellbeing of their occupants. Healthy indoor environments are no longer a luxury—they have become an essential requirement for modern workplaces.
Trigger: The Return to the Office
Over the past few years, remote and hybrid working have become the norm for millions of employees. As people split their time between home and workplace, many buildings adapted to reduced occupancy, lower internal heat loads, and different ventilation patterns. Today, however, many organisations are gradually encouraging—or requiring—their employees to return to the office. However, many buildings were designed around assumptions that no longer reflect today's working patterns. Others have simply aged, with HVAC systems that are no longer operating optimally.
A return to full occupancy means higher CO2 levels, increased cooling demand and greater pressure on ventilation systems—precisely the conditions under which Indoor Air Quality becomes most critical. Rising occupancy rates raise a critical question: Are our office buildings ready to welcome people back?
Symptoms: When the Building Becomes the Problem
As occupancy rises, so does the pressure on building systems. More people generate higher CO2 levels and greater cooling demand. If ventilation and temperature control can not keep pace, indoor conditions deteriorate, employee wellbeing suffers and productivity declines.
Employees may experience symptoms such as headaches, fatigue, dry eyes, irritation of the nose or throat, difficulty concentrating and a general feeling of discomfort. This phenomenon even has a name: Sick Building Syndrome (SBS). It is not a single disease but rather a cluster of symptoms linked to time spent inside a particular building. Remarkably, these symptoms often diminish or disappear shortly after leaving the building.
Although SBS can have multiple contributing factors, poor IAQ, inadequate ventilation, improper temperature control, excessive humidity and insufficient building maintenance are among the most common causes.
Diagnosis: A Vicious Circle
The consequences of poor IAQ extend well beyond occupant comfort. Research consistently shows that indoor environmental quality influences cognitive performance, concentration, absenteeism and overall workplace satisfaction. Employees who are uncomfortable, fatigued or distracted simply perform less effectively.
Ironically, organisations that bring employees back to the office to strengthen collaboration and productivity may achieve the opposite effect if the workplace fails to provide a healthy, comfortable environment. Instead of supporting these goals, the workplace undermines the very benefits employers hoped to achieve by bringing employees back to the office.
Side effect: The Climate Challenge
These challenges become even more pronounced during increasingly frequent heatwaves. Rising outdoor temperatures increase cooling demand, while simultaneously putting the efficiency of many conventional HVAC systems under increasing pressure. Buildings often struggle to maintain acceptable indoor conditions, creating a delicate balance between energy efficiency, thermal comfort and healthy indoor air. This is precisely where intelligent control strategies and free cooling can make a significant difference!
Treatment: Building Therapy
Fortunately, many of these challenges can be prevented with the right strategies.
Smart HVAC control, continuous IAQ monitoring and intelligent automation allow indoor environments to adapt dynamically to occupancy, weather conditions and cooling demand. Technologies such as free cooling can reduce mechanical cooling requirements while maintaining comfortable indoor conditions whenever outdoor temperatures permit.
As building management becomes increasingly data-driven, advanced controllers play a crucial role in optimising both occupant wellbeing and energy performance. The healthiest workplaces are no longer those that simply heat and cool—they are the ones that continuously adapt. Because perhaps the best therapy for a sick building is not treating the people inside it, but treating the building itself.
Prognosis: Healthy Buildings, Happy People
That’s why Sentera is introducing a new free cooling controller, designed to optimise ventilation and cooling strategies automatically—helping buildings stay comfortable, energy-efficient and ready for whatever the weather brings.The future of healthy buildings lies not only in better HVAC equipment, but in smarter control.
Free cooling is the most important application of ventilation in function of temperature. It is a valuable alternative or supplement to air conditioning. As outdoor temperatures drop during the night, the ventilation system draws in cooler air to reduce the building’s internal temperature. Over time, the building gradually cools down. Once the desired temperature is reached, the system reduces or stops the supply of outdoor air. Free cooling is more cost-effective than traditional air conditioning, while the use of fresh outdoor air also contributes to better Indoor Air Quality.
The future of indoor comfort is not about using more energy—it is about using it smarter. With intelligent HVAC control and free cooling strategies, buildings can become healthier, more efficient and better prepared for tomorrow’s challenges.
Ready to improve your indoor environment?