Get advice on spotting warning signals along with peculiar noises or smells coming from an air conditioner; early detection

https://www.mediafire.com/file/3qyvtuq2jcop1p1/pdf-54086-31521.pdf/file

Get hints on recognizing warning signs and symptoms corresponding to peculiar noises or smells coming from an air conditioner; early detection ends in well timed interventions fighting extra injury down the road!