air-Q in action: Kurt-Masur School in Leipzig—analysis of the causes of summer temperature problems
Find out here how the air-Q can be used in a school to improve indoor air quality.
What is this measurement about?
Since 2019, the Kurt-Masur School has been struggling with overheated classrooms and poor ventilation, especially during the summer months. Teachers and students report problems with concentration, headaches, and restricted class activities. Temperature issues also arise in the winter, with classrooms becoming uncomfortably cold at the beginning of the week. The goal of the project is to improve these conditions and find sustainable solutions.
In 2019, the school approached the parents’ council regarding overheated classrooms and poor air quality. Parents, teachers, and the daycare staff also confirmed the problems, which occurred in both summer and winter. A working group (the “AG Hitze,” or Heat Working Group) was formed to find solutions, but obstacles such as costs, planning, and fire safety regulations hindered the implementation of measures.
In 2024, the school began systematically recording classroom temperatures and sent the results to the architecture firm.
At the initiative of the parents' council, air-Q offered to measure and evaluate relevant indoor air quality parameters in predefined classrooms. In one of these classrooms, a small air conditioner was operated in parallel, as the school administration is considering installing them in classrooms that are particularly affected as a possible step toward a solution.
How was the measurement taken?
To analyze the situation, air-Q light indoor air quality monitors were installed in two classrooms between August 21 and September 9. Every 2 minutes, the devices recorded atmospheric pressure, temperature, carbon dioxide concentration, relative humidity, and the concentration of volatile organic compounds.
While temperature measurements allow us to track the warming of classrooms, measurements of humidity, volatile organic compound concentrations, and carbon dioxide enable us to draw conclusions about the ambient thermal comfort, the intensity of air exchange achieved, and certain basic parameters for evaluating air quality.
By measuring carbon dioxide concentrations, it is possible to determine when a room is in use and whether high levels of carbon dioxide may be causing discomfort, headaches, or dizziness. Both the selection of measured values and their high temporal resolution make it possible not only to draw conclusions about the average levels of these variables, but also to gain insight into the temporal relationships between them.
In addition, freely available, existing outdoor temperature data were used to qualitatively assess the influence of outdoor temperatures on indoor temperatures.
What are the results of the measurement?
Temperature
- The room temperatures during class were consistently too high (between 26 °C and over 30 °C).
- The main causes are direct sunlight on glass facades and the heat generated by people and equipment.
- There is no noticeable nighttime cooling due to the building's high thermal storage capacity.
Air Quality
- CO2 levels and air humidity remained within an acceptable range.
- VOC concentrations showed only occasional spikes, likely due to the use of the room or the materials present in it.
- The ventilation system provides an adequate supply of fresh air, but it does not actively cool the classrooms.
The measurement results confirm that high temperatures pose the greatest challenge to school operations. The proposed measures to improve ventilation and shading offer short-term solutions, while the possibility of active cooling should be evaluated over the longer term. The priority is to implement a “free cooling” program to efficiently utilize cool outdoor air at night, with the goal of achieving a sustainable improvement in the indoor climate.
Key Features of the air-Q for Measurements at the Kurt-Masur School
Comprehensive data collection: The air-Q measuring device allows for the simultaneous measurement of various air pollutants, such as temperature, carbon dioxide (CO2), relative humidity, and volatile organic compounds (VOCs). Two air-Q light devices were used for the measurement. High-frequency measurements (every 2 minutes) enable precise analysis of changes in temperature and air quality.
Flexibility and ease of use: The air-Q is compact, easy to install, and easy to transport, making it ideal for use in a variety of spaces. This flexibility has made it possible to collect detailed data in different classrooms.
Real-time monitoring: The air-Q’s ability to transmit real-time air quality data to the air-Q Cloud allows even non-experts to quickly access the data, rapidly identify specific sources of pollution, and deepen their understanding of air quality. This can not only raise awareness about indoor air pollution but also lead to practical changes in the daily routines of teachers and children, such as ventilating more regularly.
Interview with the Kurt Masur School
Discover interesting facts in our interview with Christiane Dubiel, assistant principal at the Kurt-Masur School, and Robert Pohl, a dedicated engineer and expert who is the father of a child attending the school.
Learn more about the measurements taken at Kurt-Masur School using three air-Q devices. The interview was conducted in February 2025 and offers practical insights and solutions that can also be applied to other schools.
Question 1: How can the high temperatures at Kurt-Masur School be explained? What role does the indoor climate play in the concentration and well-being of students and teachers?
Robert Pohl, an engineer and the father of a child enrolled at the school:
Unacceptably high ambient temperatures are recorded primarily on the top two floors, on the east, south, and west sides of the building, as well as on the rooftop terrace. Several causes are worth mentioning:
1. The permanent overcrowding of the school building means that both upper floors must be used simultaneously during operating hours, even though the design specifications for the installed ventilation system only provide for the ventilation of one upper floor in use, while the unused floor should only be ventilated to a minimum level. In addition, there are other unfavorable layout features: the classrooms, daycare rooms, and rec rooms used continuously by the children are, for the most part, located precisely on those upper floors and in exactly the three sections of the building that are constantly exposed to the sun. In contrast, the teachers’ lounge, the school administration offices, the school office, the locker rooms, the restrooms, and the art and workshop rooms—which are used only occasionally—are located on the north side of the building, which is noticeably cooler. The cool ground floor houses the workshop room and some preschool activity rooms, as well as the dining hall—that is, rooms used only temporarily. The preschool’s kitchen has no windows that open.
2. There is no effective shading, so that—due to intense solar radiation—the building envelope heats up in the three areas mentioned despite the insulation. As a result, the rooftop terrace cannot be used during the day, not even in summer, due to the acute health risk of heatstroke. The situation is exacerbated by the fact that the blinds installed to shade the glass facades automatically raise at the slightest breeze; thus, unfortunately, they provide shade only on very rare occasions, when the wind is almost completely still. Furthermore, due to their design, they also block any other airflow between the blind and the window, which contributes to the heating of the building.
3. It can be assumed that the ventilation system’s controls are not functioning optimally within the existing structural constraints. While there is at least sufficient air exchange, no cooling is noticeable, even when the temperature drops below 15 °C on cool summer nights.
4. The building was architecturally designed with relatively low ceiling heights. In keeping with passive house standards, a mechanical ventilation system was chosen to provide the necessary ventilation instead of large windows that could be opened manually.
5. From an urban planning perspective, it should be noted that the school building is located in a very enclosed area of the city. As a result, hot days and tropical nights set in earlier there than on the outskirts. The sparse vegetation lining the streets—in the form of shade trees—cannot provide any noticeable cooling for the building.
Christiane Dubiel, assistant director of the center:
The heat in the building persists even at night, so the classrooms and hallways do not cool down. These high temperatures significantly affect the concentration of children and adults. In addition, people in the building suffer from headaches, fatigue, and general discomfort. Requests for exemption from the obligation to attend school have already been submitted due to the heat in the classrooms. The persistent heat places a growing burden on everyone in the building, which negatively impacts their ability to learn and work.
Question 2: Why can't problems be solved as quickly as necessary?
Robert Pohl, an engineer and the father of a child enrolled at the school:
Within the framework of meticulously defined chains of command and allocated responsibilities, there is no viable, established channel that—according to established administrative practice—would help resolve these issues among the school’s administration, the daycare center’s administration, the LaSuB (regional office for schools and training), the daycare center’s managing body, the building owner, and the building operator, as well as organizations such as health and safety, occupational safety, child welfare services, or workers’ compensation insurance. This issue is relatively recent. Given the overcrowding, the building’s demanding energy standards as a passive house, and the significant and growing rise in summer temperatures—especially in densely built-up neighborhoods—the heating of the school building likely needs to be assessed differently today than was foreseeable at the time of planning.
In addition, Leipzig continues to be a growing city, with all the challenges that this entails (financial and staffing resources, as well as addressing the challenges of climate change).
Over the years, more than 20 measures to cool or shade the building have been discussed, but they have been implemented with only limited success. And there was uncertainty regarding the potential, performance, and flexibility of the existing ventilation system.
Christiane Dubiel, assistant director of the center:
For years, the school has had a “heat” task force, which has discussed various measures to improve the situation regarding heat. Among the proposed measures are:
• Tree planting
• Shading for the rooftop terrace and patio
• Landscaping of the facade
• Regular classroom changes for classes
• Tours led by architects specializing in climate
• Refusal to accept new students to prevent overcrowding
• Portable air conditioners in classrooms
• Raising awareness of the issue in the district council
• Applying film to windows
• Conversations with Architects
However, there is a lack of openness regarding this issue, as well as a lack of cooperation among the various agencies, which results in a lack of clear accountability and a reduced flow of information.
Last year, the school’s staff council consulted the company physician. She took a stand and once again sought assistance from various agencies. As a result, the school administration was asked to obtain opinions from the workers’ compensation insurance provider and the occupational safety specialist on the issue of “heat at KMS.” We are still waiting for the occupational safety specialist’s opinion.
Question 3: How were the measurements conducted, and which classrooms were tested? What specific challenges arose when taking measurements at this school? How can the air-Q help in this situation?
Robert Pohl, an engineer and the father of a child enrolled at the school:
On the second floor, an air-Q was installed simultaneously in two occupied classrooms (26 children + 2 teachers), right next to the door, facing the east-facing glass facade, mounted on a console, measuring indoor air parameters at the head height of the seated children. Each unit operated for 2 weeks. The challenge was to ensure the best possible comparability between the classrooms (in terms of their orientation within the building) and to position the air-Q safely, yet close to the children and a power outlet.
The air-Q can be used here because, thanks to its LEDs, it also provides children with interesting feedback—it’s not just a passive device. High-frequency measurements taken every 2 minutes make it possible to identify temporal relationships between indoor air parameters and room usage—for example, how long the room was ventilated before classes began or whether the room was still in use in the afternoon. Even so, the volume of data to be analyzed remains manageable and can be presented in a meaningful way over periods of several weeks.
La limitación de proximidad (< 2 m) a un enchufe puede superarse con una batería externa de dimensiones suficientes.
Christiane Dubiel, assistant director of the center:
Since the air-Q records and collects data digitally, other comparative data (such as outdoor temperature readings) could be incorporated into the analysis. As a result, our school now has documentation of issues that previously could only be perceived (overheated classrooms). At the same time, thanks to the complexity of the measured values, we were able to document the air quality in the classrooms.
With the written evaluation of the measurement data, we now have a basis for further discussions. The perceptions of those who use the building can no longer be dismissed so easily.
Question 4: Were the results as expected? Were there any surprises?
Robert Pohl, an engineer and the father of a child enrolled at the school:
As for the room temperature, the measurements unfortunately confirm the conditions perceived and described subjectively by students, teachers, and parents. With a room temperature of 30 °C, it is not possible to maintain concentration during learning or to conduct a representative assessment of performance, which runs counter to the school’s purpose and the reason for its existence. Unfortunately, according to those who have been active at the school for many years, the measured temperatures are not just a temporary, short-term phenomenon; rather, depending on the timing of the summer break, they can have an unsustainable impact on school operations for two months and on the daycare service even during the summer break.
Two findings are particularly surprising: First, air exchange is sufficiently effective, so that even in a full classroom, no significantly fatiguing CO2 concentration or unhealthy VOC concentration (volatile organic compounds, colloquially known as “odors”) is detected. Nor is the humidity a cause for complaint. It follows that the ventilation system works well enough that it is not necessary to keep the windows open permanently—a requirement for compliance with the passive house standard. The subjective discomfort is due solely to the high temperature. Second, the morning ventilation produces a noticeable cooling effect that, however, wears off almost immediately when the window is closed at the start of classes. It follows that the period of manual ventilation is too short to cool not only the air in the room but also the building structure as a whole.
Question 5: As an expert on indoor air quality, do you have any tips for quickly lowering temperatures? What immediate steps could help improve indoor air quality in the short term?
Robert Pohl, an engineer and the father of a child enrolled at the school:
Ideally, whenever the outdoor temperature is lower than the indoor temperature (between 20 and 22 °C)—in spring, summer, and increasingly in the fall—there should be noticeable ventilation with outdoor air. To achieve this, it is best to use the existing ventilation system to avoid manual cross-ventilation, which is limited in scope. Assuming staff are available, manual ventilation can be implemented immediately, but it should not be carried out while students are present or staff are absent.
Assuming that the specifications are clear and the contract is awarded, optimizing the ventilation system is also a promising short-term solution, which—perhaps supplemented by two or three rounds of iteration over the course of two years—is also a reasonable long-term approach.
Question 6: Are there any sustainable construction or technical measures that could provide a long-term solution?
Robert Pohl, an engineer and the father of a child enrolled at the school:
Through structural and technical measures, it is possible to prevent the building from overheating in a permanent and sustainable manner. Assuming the necessary resources were available—and that they were not diverted to other public facilities facing similar or more serious problems—it would, in theory, be possible to regulate and maintain the temperature at a comfortable level, for example through active cooling, which could be powered by the recently installed rooftop photovoltaic system with a nominal output of more than 90 kW. Shading through landscaping also promises a long-term solution. Both measures, however, entail not only a high level of investment but also, during operation, competent, periodic, and documented maintenance, care, upkeep, and repairs. Against the backdrop of constantly changing conditions—such as special ventilation requirements during a pandemic or prolonged periods of drought—responsibilities must also be developed at the staff level, preferably across multiple facilities. This would make it easier to adapt to other facilities in a more targeted manner than if each facility were to develop its own structures based on existing capabilities and limitations.
Christiane Dubiel, assistant director of the center:
Parents often ask me if a less overcrowded school might help alleviate the problem of heat in the classrooms. Unfortunately, I always have to tell parents that I can’t assess that and that we also can’t verify it in the short term, since the next first-grade class will again consist of five classes.