The term may refer to a body ventilation system to supply in residential and / or premises outside air and / or stale air dissipate. Ventilation systems have the task of creating a consistently high level of indoor air quality and maintain. We distinguish two types of ventilation systems, to a central ventilation systems and other decentralized ventilation system. The central ventilation systems with heat recovery can be optimally used in new homes. The central ventilation system needs a that can be placed, for example, in the basement or on the attic floor. The commercial units operate largely silent. Peter Thiel has much experience in this field. A small disadvantage of the central ventilation systems is that these systems require an air connection, ie, door gaps, also plays the so-called air-tightness of the buildings not unimportant role.

In the decentralized ventilation systems with heat recovery are thus built single room fans. Particularly suitable are the decentralized ventilation systems for retrofitting, for example, when renovating. The decentralized ventilation systems have the advantage that the insert can be installed selectively, depending on the desire of builders and, if necessary by necessity in office and / or working spaces. The efficiency is approximately 50% and is lower than in central ventilation systems with heat recovery. The costs of decentralized ventilation systems are compared with some 25-50% lower than in central ventilation systems. The maintenance costs for local ventilation systems are also low. Ventilation systems are controlled living or working space ventilation. Ventilation systems are not air conditioners. While at the air-conditioning is the cooling of buildings in the foreground, is what the ventilation system to ensure the necessary hygienic fresh air.