Air Quality & Ventilation — Czechia
A practical reference for understanding indoor air quality sensors, mechanical ventilation systems, heat recovery units and filter upkeep in Czech residential buildings.
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Each article covers a different layer of indoor air management — from monitoring to airflow to maintenance.
IAQ Sensors
A look at CO₂, PM2.5, VOC and humidity sensors — what each measures, how readings translate into real conditions, and which devices have been tested in Central European climates.
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HRV Systems
Heat recovery ventilators move stale air out and fresh air in without shedding the warmth you paid to generate. An overview of how they work, typical efficiency figures and installation considerations for panel flats and family houses.
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Filter Maintenance
HEPA, activated carbon and G4 pre-filters each degrade at different rates. This guide maps filter types to replacement intervals and explains what happens to air quality when maintenance is skipped.
Read more →Why It Matters
Older panel construction, tight double-glazing retrofits and city-centre traffic combine to trap pollutants inside. Czech environmental monitoring data from the Czech Hydrometeorological Institute (ČHMÚ) consistently shows elevated PM2.5 in urban apartments during heating season.
CO₂
A bedroom with two people and closed windows can exceed 2,000 ppm within two hours — well above the 1,000 ppm threshold where concentration and sleep quality begin to decline, according to research published by the WHO.
Humidity
Czech winters push relative humidity indoors. Without mechanical extraction in kitchens and bathrooms, moisture accumulates on cold external walls — creating conditions for mould growth within six to twelve weeks.
PM2.5
Annual average PM2.5 concentrations in Prague and Ostrava regularly exceed WHO guideline levels. Without HEPA filtration, this outdoor load migrates indoors through gaps around window frames and ventilation openings.
Reference
Czech buildings follow European norms. The table below provides context for interpreting sensor readings.
| Pollutant | Good | Acceptable | Poor | Standard |
|---|---|---|---|---|
| CO₂ | < 800 ppm | 800–1,200 ppm | > 1,500 ppm | EN 13779 |
| PM2.5 | < 10 µg/m³ | 10–25 µg/m³ | > 35 µg/m³ | WHO 2021 |
| Relative Humidity | 40–60 % | 30–70 % | < 25 % or > 75 % | ČSN EN ISO 7730 |
| TVOC | < 300 µg/m³ | 300–1,000 µg/m³ | > 3,000 µg/m³ | WHO / AgBB |