Get advice on spotting caution signs reminiscent of ordinary noises or smells coming from an air conditioner; early detection

http://www.mediafire.com/file/z8yxtxrrdoqpfvy/pdf-70906-67955.pdf

Get guidelines on spotting caution signals corresponding to wonderful noises or smells coming from an air conditioner; early detection ends in timely interventions combating further hurt down the line!