Definition for word: Infiltration

Air movement from exterior to interior. The opposite of exfiltration.

Referrence from

Infiltration is the unintentional or accidental introduction of outside air into a building, typically through cracks in the building envelope and through use of doors for passage. Infiltration is sometimes called air leakage. The leakage of room air out of a building, intentionally or not, is called exfiltration. Infiltration is caused by wind, building pressurization and by air buoyancy forces known commonly as the stack effect.

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