Ventilation techniques are methods used to improve air circulation and quality in indoor spaces. These techniques can include natural ventilation, which relies on outdoor air flow through windows and vents, and mechanical ventilation, which uses fans and air conditioning systems to control air movement. Proper ventilation helps reduce indoor pollutants and maintain comfortable temperatures. Another important aspect of ventilation is the exchange of stale indoor air with fresh outdoor air. This can be achieved through various systems, such as HVAC (Heating, Ventilation, and Air Conditioning) systems, which filter and condition the air. Effective ventilation is essential for health, comfort, and energy efficiency in buildings.