When my air conditioning is functioning properly, it makes actually little noise; There is a quiet humming when the cooling component first starts up… About a week ago, the indoor components started making excessive & different noises, but i was reluctant to hire a professional for repair because of the high cost of service, but even if the professional needs to do nothing more than tighten a wire or wipe a fan blade, there’s a sizable charge involved. If updatement parts are needed, the expense can become a major drain on the budget. I decided to do some research online & see if I could diagnose the problem on my own. I was hoping the issue was something minor that I could repair without needing to hire a professional. I read that dander, dust, pollen & even small rodents sporadically get stuck inside the air duct. The buildup of debris obstructs airflow & causes the method to be much noisier than usual. If this is the problem, it’s necessary to let a knowledgeable professional handle duct testing & cleaning. When the noise originates from the outdoor components, it could be the result of a number of things. A squealing noise is constantly a sign of too much internal pressure built up within the cooling system. This requires calling for help. A hissing noise is likely caused by a refrigerant leak & often leads to inefficient cooling. It’s best to schedule a repair with a certified business. A buzzing noise normally points to an electrical issue with the condenser, fan motor, relay switch or wiring… Since electrical concerns can be dangerous, it’s not recommended to attempt a DIY repair; No matter the situation, it seems necessary to spend the cash for professional service.