I bought I ton Hitachi split a/c about six months ago. I am unable to operate at night as my neighour complained that they could not sleep due to noise generated by outdoor unit. When I wrote to Hitachi about this their engineer came with decibel meter and noise level was found to be as high as 75 dB . Permissible noise level in recidential complex is 45 dB as per statutory regulation. Now-a-days every rotating equipment is manufactured following noise level guidance.
But when I requested Hitachi to provide me manufacturing specifications they failed to provide the same. I have compared the noise level of split a/c of other maker and it is limited to 50 dB. It is very clear that Hitachi machine is not suitable for use in residential complex. I am yet to receive a satisfactory solution from Hitachi inspite of several remindes. Please do not buy hitachi machine if you are living in a multistoried residential complex.
You may install it but will not be able to use it due objection from your neighour.
A.K. Bhattacharyya