How to Choose a Ventilation System

Ventilation Calculation

How to Choose a Ventilation System

Using the example of a combined bathroom, to select the right exhaust system, measure the length, width, and height of the room using a tape measure. Enter these values into the calculator.

In the “Room type” dropdown menu, select “Toilet” (as the ventilation capacity for a combined bathroom should be higher than for a separate one). Round up the calculated value.

For example, if the required ventilation capacity is 277 m³/h, choose an exhaust system rated at 280 m³/h. If this exact capacity is unavailable, a 300 m³/h or 320 m³/h model would also be suitable.

Why Ventilation Is Important

Ventilation is a crucial engineering system in any building, essential for maintaining comfortable and healthy indoor conditions. However, its importance is often underestimated, especially in residential spaces, where poor ventilation can lead to increased humidity, indoor air pollution, and health issues.

A well-designed ventilation system serves several key functions:

  • Regulates humidity levels by removing moisture-laden air generated from cooking, bathroom use, laundry, and human respiration, helping to prevent condensation and mold growth.
  • Removes excess carbon dioxide, pollutants, and dust, ensuring a constant supply of fresh, oxygen-rich air, which improves air quality and overall well-being.
  • Reduces airborne pathogens through proper air exchange, making ventilation an essential element of mechanical air purification and disinfection.
  • Prevents mold growth, as insufficient ventilation is one of the most common causes of excessive indoor humidity, which promotes mold and mildew formation.

In addition to comfort, proper ventilation plays a critical role in maintaining health, protecting building structures, and ensuring air quality that meets hygiene and safety standards.

Ventilation Selection Based on Occupancy

Exhaust Calculation Based on Occupancy and Physical Activity (Per Person)

  • 20–40 m³/h for minimal physical activity
  • 45 m³/h for light physical activity
  • 60 m³/h for heavy physical activity
  • 80 m³/h per person in a gym

For residential rooms in apartments, hotels, or dormitories, ventilation should have a capacity of at least 3 m³/h per 1 m² of living space.

Experimental Data:

  • During sleep, a person exhales 40 g of water vapor and 15 liters of CO₂ per hour.
  • At rest, a person exhales 32 g of water vapor, 16.7 liters of CO₂, and inhales 15 liters of O₂ per hour.
  • During work, a person exhales 58 g of water vapor, 43 liters of CO₂, and inhales 30 liters of O₂ per hour.

Source: Based on experiments by H. Wolpert.