The invention relates to a low-
noise type ultrathin overhead
type frequency-conversion shelter air conditioner which mainly comprises chassises, an outdoor
heat exchanger and an indoor
heat exchanger, wherein the outdoor
heat exchanger comprises two axial flow fans, a condenser and a frequency-conversion compressor, the condenser is installed on a
chassis in an outdoor casing, and the vibration center line of the frequency-conversion compressor is superposed with the center line of the width direction of the
chassis; and the indoor heat exchanger comprises an
evaporator, an expansion valve, a filter, a
volute-free centrifugal blower and an
evaporator cover, wherein the
evaporator is installed in the center of a
chassis of the indoor heat exchanger, a chassis of an inner ring of the evaporator is provided with a return air inlet with an air deflector, four air outlets are evenly arranged on a chassis of an outer ring of the evaporator, the evaporator, the return air inlet, the air deflector and the four air outlets are all packaged in the evaporator cover, and the
volute-free centrifugal blower is fixed below the evaporator cover and is correspondingly consistent to the center of the return air inlet. The invention has reasonable design, compact structure, balanced running of the air conditioner,
low noise, large air output and good
refrigeration effect and is suitable for a shelter air conditioner with high requirement to an indoor
working environment to use.