air pollution observation station
air sea flux observation
upper air meteorological observation
Air Leakage Rate of Air Preheater
air to air heat recovery unit
air to air missile launching envelope
arctic air [= arctic air mass]
continental air [= continental air mass]
main air port exhaust air
marine air [= marine air mass
variable air volume (VAV) air conditioning system
variable air volume air conditioning system
adjustment for a mixed network consisting of both GPS observation and conventional observation
1# 10000 m3 air separation unit
135 MW direct air cooling unit