Direktventilation

Direktventilation, often translated as direct ventilation, refers to a method of air exchange in buildings where fresh outdoor air is introduced directly into the occupied space. This contrasts with systems that might precondition air or recirculate a significant portion of indoor air. In its simplest form, direct ventilation can be achieved through openable windows or doors. However, in modern building design, it is more commonly associated with mechanical ventilation systems that utilize dedicated supply and exhaust fans to control the flow of outdoor air.

The primary purpose of direct ventilation is to provide occupants with fresh air, thereby diluting indoor air pollutants such as carbon dioxide, volatile organic compounds, and moisture. This is crucial for maintaining good indoor air quality and occupant health and comfort. Depending on the design, direct ventilation systems can be balanced, meaning the amount of air supplied equals the amount of air exhausted, or unbalanced. The outdoor air supplied is typically filtered to remove particulate matter before entering the building.

While direct ventilation offers benefits in terms of air quality, it also presents challenges. Introducing unconditioned outdoor air can lead to increased heating and cooling loads, potentially impacting energy efficiency. In regions with poor outdoor air quality, direct ventilation without adequate filtration can introduce pollutants into the building. Therefore, the design and operation of direct ventilation systems require careful consideration of climate, local air quality, and energy consumption. Energy recovery ventilators (ERVs) and heat recovery ventilators (HRVs) are often integrated into direct ventilation systems to mitigate energy losses by transferring heat and moisture between the outgoing stale air and the incoming fresh air.