A data center having a hot aisle, a cold aisle, a row of server rack cabinets located between the cold aisle and the hot aisle, and a self-expanding gap filler located in a gap between adjacent elements in the data center is provided. The self-expanding gap filler includes a compressible material and a tubular outer member defining an inner space, the tubular outer member encapsulating the compressible material within the inner space. The compressible material is configured to expand from a compressed state within the inner space of the tubular outer member to an expanded state within the inner space of the tubular outer member in response to a seal being at least partially released within the tubular outer member to allow air to flow into the inner space of the tubular outer member, whereby the self-expanding gap filler at least partially fills the gap between the adjacent elements in the data center.