機器
air
airflow
background
blades
blower
building
circle
cold
conditioner
conditioning
construction
cool
cooling
copy space
detail
engine
extractor
factory
factory wall
fan
industrial
industry
machinery
mechanical
metal
old
pattern
plant
power
rotate
rotating
round
rust
structure
three
turbine
ventialtion
ventilate
ventilating
ventilation
ventilator
wall