Air flow outward through a wall, building envelope, etc.
Exfiltration test
Check for leaks in a buried water line by filling a manhole, by the part of the line in question, with water and watching it to find a sign of leakage.
Exfoliation
Physical weathering or chemical action creating a peeling off of some surface stone or masonry. Moisture freezing in surface cracks causes expansion, creating exfoliation.
Exhaust
Air removed deliberately from a space, by a fan or other means, usually to remove contaminants from a location near their source. The air flow leaving the treated space. Exhaust may be accomplished by one or more of the following methods - A. EXTRACTION: exhaust in such a manner that the air is discharged into the atmosphere. B. RELIEF: exhaust in such a manner that the air is allowed to escape from the treated space if the pressure in that space rises above a specified level. C. RECIRCULATION - exhaust in which the air is returned to the air treatment system. D. TRANSFER - exhaust in which air passes from the treated space to another treated space.
Exhaust air flow rate
Volume of air leaving an exhaust air terminal device within a time unit.
Exhaust air terminal device
Air terminaI device through which air leaves the treated space.
Exhaust fan
Ventilating device to remove smoke, undesired odors, stale or hot air or water vapor. Venting is normally done to the outside.
Exhaust vent
A device used to vent air from the roof cavity with vents that are installed on or near the higher portions of the roof such as the ridge.
Existing grade
Grade at an excavation site prior to commencement of work.
