civil air defense basements
Civil air defense engineering
Civil Air Defense projects
Civil Air Defense Works
high-rise building civil air defense basement
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
1# 10000 m3 air separation unit