Ventilation Calculator

Required airflow is calculated as room volume multiplied by the air change rate, compared against 20 m³/h per person. The higher value is used to ensure both adequate ventilation and occupant comfort.

Building standards typically require a minimum of 0.5 air changes per hour (ACH) for residential rooms. Kitchens require up to 10 ACH due to cooking-related moisture and odors.

Cooking generates large amounts of water vapor, grease particles and odors. Standards require 10 ACH for kitchens. In this calculator, kitchen mode sums both volume-based and occupancy-based flows.

ACH indicates how many times per hour the entire air volume in a room is replaced with fresh air. Residential spaces need at least 0.5 ACH, offices around 1.5 ACH, and kitchens up to 10 ACH.

Proper ventilation removes CO₂, excess humidity, allergens and VOCs. Insufficient air exchange leads to mold growth, increased CO₂ levels and reduced occupant wellbeing.

Natural ventilation relies on temperature and pressure differences and requires no electricity, but is weather-dependent. Mechanical ventilation uses fans to provide a controlled, consistent airflow regardless of outdoor conditions.

HRV (or recuperation) recovers heat from exhaust air and transfers it to incoming fresh air. Modern units recover 70–90% of heat energy, significantly reducing heating costs while maintaining required fresh air supply.

Choose a fan with a rated airflow at least 10–20% higher than the calculated requirement to account for duct resistance. For a 200 m³/h requirement, select a fan rated for at least 220–240 m³/h.

Yes, each person requires a minimum of 20 m³/h of fresh air for comfort and health. In offices or meeting rooms with many people, the occupancy criterion often dominates over the volume-based calculation.

Room volume equals floor area multiplied by ceiling height (V = A × h). For a 30 m² room with a 2.5 m ceiling, volume is 75 m³. This figure is the basis for all ventilation calculations.