Abstract: A fan slide-in unit, module or chassis of the type used for cooling electronic assemblies. The fan slide-in unit constructed in modular manner having a plurality of fan installation locations arranged in rows and which comprises two half-shells made from substantially acoustically inert material. The number and location of the individual fans can comply with the needs of the particular individual, the installation locations left free being made air-impermeable. The ready electrical connection possibility provided for each installation location permits an easy changeover. In addition, the mounting of the individual fans in the half-shells takes place in solid-borne sound-decoupled manner, so that essentially there is only the noise caused by the air flow. The fans used are controlled in unitary manner by a manually adjustable control block, which can be guided in a temperature or parameter-dependent manner.