A building architectural element (vestibule) with two airtight doors that reduces the amount of air infiltration and exfiltration when the exterior most door is opened.
Airtight drywall approach (ada)
A building construction technique used to create a continuous air retarder that uses the drywall, gaskets, and caulking. Gaskets are used rather than caulking to seal the drywall at the top and bottom. Although it is an effective energy-saving technique, it was designed to keep airborne moisture from damaging insulation and building materials within the wall cavity.
Aisle
Pathway through sections of a building or room, such as between sections of seats in a theater.
Ak value
Quotient obtained by dividing a measured air flow rate by a measured air velocity according to a specific process and a specific instrument.
Alabaster
Usually used for carved ornaments, this is a fine-grained gypsum.
Alarm check valve
A check valve located in the riser of a wet pipe fire sprinkler system that sounds an alarm when water begins to pass through it.
Albedo
The ratio of light reflected by a surface to the light falling on it.
Alcohol
A group of organic compounds composed of carbon, hydrogen, and oxygen; a series of molecules composed of a hydrocarbon plus a hydroxyl group; includes methanol, ethanol, isopropyl alcohol and others.
Alcove
A recessed space connected at the side of a larger room.
