As temperatures rise, indoor conditions also change. Rooms heat up more quickly, humidity fluctuates more, and many people ventilate less frequently during the day to keep the heat out. As a result, various air pollutants and irritants can accumulate, affecting well-being, sleep quality, and concentration.
If you know the most important indoor air quality metrics and keep an eye on them, you can take timely action to ensure a comfortable and healthy indoor environment. But which metrics are particularly relevant in the summer?
CO₂: An Important Indicator of Air Quality
Carbon dioxide (CO₂) is produced wherever people breathe. In poorly ventilated rooms, its concentration rises quickly, especially in offices, bedrooms, classrooms, or conference rooms.
Guideline Values for CO₂
Humidity: Between a Comfortable Climate and the Risk of Mold
Relative humidity has a major impact on indoor climate. In the summer, it can rise significantly, especially after rain or on humid days.
Recommended Humidity Level
Relative humidity levels between 40 and 60 percent are considered ideal for living and working spaces.
If the humidity is consistently too high, the following problems may arise:
- MoldGrowth
- Growth of House Dust Mites
- unpleasant odors
- Damage to furniture and building structures
On the other hand, air that is too dry can irritate the mucous membranes and affect your well-being.
Temperature: More Than Just a Matter of Comfort
Room temperature affects not only personal well-being, but also concentration and performance—
Recommended temperatures:
- Living spaces: 20 to 24 °C
- Bedroom: 16 to 20 °C
- Offices: 20 to 26 °C
Temperatures as high as 26 °C can already impair concentration. This effect is often exacerbated when combined with elevated CO₂ levels or high humidity.
Ozone: Summer Pollution from Outdoor Air
Ozone is produced primarily on sunny, hot days through chemical reactions in the atmosphere. Levels can rise significantly during the summer months, especially in urban areas.
Ozone can:
- irritate the respiratory tract
- Causes of a Cough
- impair lung function
- exacerbate existing respiratory conditions
Therefore, anyone who ventilates their home on hot days should not focus solely on the temperature. Ozone levels are often significantly lower in the early morning hours than in the afternoon.
particulates: Also relevant in the summer
particulates is often associated with winter or road traffic. In fact, pollution levels can also be higher in the summer.
Possible sources include:
- Road Traffic
- Construction Sites
- Forest and Vegetation Fires
- Barbecue smoke
- Pollen fragments
- Sahara Dust Events
Small particles, particularly those in the PM2.5 and PM1 size ranges, can penetrate deep into the respiratory tract and pose a health risk.
Volatile organic compounds (VOC)
VOC stands for “Volatile Organic Compounds.” These substances are released by many everyday products.
Typical sources include:
- Furniture
- Paints and Varnishes
- Cleaning products
- Floor coverings
- Adhesives
- Fragrances
In the summer, emissions from many materials increase because higher temperatures accelerate off-gassing. As a result, VOC concentrations can rise significantly, especially in poorly ventilated rooms.
Possible consequences include:
- Headache
- Fatigue
- Irritation of the eyes and respiratory tract
- unpleasant odors
Nitrogen dioxide (NO₂): A major concern, especially in cities
Nitrogen dioxide is produced primarily by combustion processes, such as those in road traffic or heating systems.
On busy roads, elevated NO₂ concentrations can enter indoor spaces through open windows. This can be particularly relevant for people with asthma or other respiratory conditions
Why Many Air Quality Problems Go Unnoticed
A common problem when assessing air quality: Many pollutants are invisible. While high temperatures or unpleasant odors are immediately noticeable, elevated levels of CO₂, particulates ozone are difficult to detect without measurement.
Subjective perception is therefore not a reliable indicator of good air quality. Often, the first symptoms—such as fatigue, headaches, or difficulty concentrating—do not appear until pollution levels have already risen.
Measuring and Understanding Air Quality in the Summer
Anyone who wants to improve air quality over the long term should continuously monitor the most important parameters. Modern air quality monitors make it possible to detect changes early on and take appropriate action.
Depending on the model, the air-Q measures a wide range of relevant air parameters, including:
- CO₂
- Temperature
- Humidity
- particulates PM1, PM2.5, and PM10)
- VOC
- Ozone
- Nitrogen dioxide (NO₂)
- Carbon monoxide (CO)
- Air Pressure and Other Environmental Parameters
The measurements are recorded in real time and displayed via an app or browser. This makes it possible to see how ventilation, changes in the weather, or other factors affect air quality.
Conclusion
Air quality in the summer is influenced by far more factors than just the outdoor temperature. In particular, CO₂, humidity, temperature, ozone, particulates VOCs can affect indoor air quality and, as a result, health, well-being, and performance.
If you know these values and check them regularly, you can take targeted steps to improve air quality and identify potential problems early on. Especially during the summer months, it’s therefore worth taking a closer look at the air quality in your home, at the office, or in public buildings.
