With a somewhat large appliance installed in a somewhat small space, noise is can be a factor. This can include a rattling noise, humming during operation, the sound of water dripping during use, or a roaring sound. While some sounds are normal and to be expected, other noises can be reduced by cleaning the air conditioner and filter and making sure the air conditioner is installed securely in the window to reduce rattling or vibration.
Although room air conditioners have gotten smaller and more streamlined in appearance over time, they are still somewhat bulky and noticeable. This may be a problem for some people who find the air conditioner unattractive, or that it detracts from the overall appearance of the room.
Air conditioners pull warm air in from the inside and pass it over condensing coils to cool it before sending it into the apartment. The process of passing the air over the condensing coils creates evaporation that drips down into a drain pan. However, if the water leaks from the drain pan, it can drip down the wall of the apartment, which can cause damage to the wall, wood, and may even become moldy if not cleaned or treated promptly.
It is possible that an indoor air conditioner may leak refrigerant gas, which can present potential health hazards to individuals and pets inside the apartment. Turn off the air conditioner and contact your landlord as soon as possible if you suspect a leak. To be safe, contact your doctor if you suspect you have been exposed to a leak.