The air conditioning is not working.
a-ria con-di-tzio-NA-ta — six syllables, stress on the fifth.
A critical complaint in Italian summer heat. Report immediately — a hot room in July is a genuine emergency.
'L'aria condizionata' — the article 'la' elides to 'l'' before vowels. This is a compound noun where 'condizionata' (conditioned) is a past participle. Italian hotels often restrict A/C to summer months; within those months, it should work.
Il climatizzatore perde acqua.
The air conditioning unit is leaking water.
A dripping unit is both a nuisance and a potential electrical hazard
L'aria condizionata fa un rumore strano.
The air conditioning is making a strange noise.
Report unusual sounds — they often indicate a mechanical problem
Fa troppo caldo in camera per dormire.
It is too hot in the room to sleep.
Emphasise the practical impact to prompt faster action
Southern Italian cities like Naples, Palermo, and Bari can reach 40°C+ in August. A non-functioning A/C is a serious problem that hotels must address urgently. If they cannot fix it, you are entitled to a different room or a discount.