The cost of on-going maintenance (and occasional repairs) for commercial air conditioning units is often higher than the initial cost of buying the conditioner and having it installed.

The secret to avoiding costly repairs on commercial air conditioners is to identify potential problems with the conditioner early enough and to take corrective measures as soon as possible. This article discusses three types of noises that a faulty air conditioner may produce as a sign that it's about time to call in the HVAC repair contractor.

The Rattling Conditioner

Defective commercial air conditioners will often produce a rattling sound. Factors that may be responsible for a rattling air conditioner include a misaligned fan in the air conditioning system as well as broken motors.

 A misaligned fan may cause the rattling sound because it strikes the fan casing when in operation. Fan misalignment is often an indication that the fan was not installed correctly. If not corrected immediately, the rattling will get louder as the misalignment gets worse. Failure of the AC's fan may be the end result.

The fans in an air conditioning unit are powered by blower motors. These motors have a large number of internal moving components. When the motor suffers physical damage (e.g. as a result of debris-related impact) internal components of the motor may get dislodged, thereby leaving them free to collide with other fixed components of the motor. This often produces a rattling sound.

The Loud Scrape

It's also common for faulty air conditioners to produce a loud scraping noise whenever the unit is turned on. The scraping noise can be likened to the sound of one metal hitting against another. In a large number of cases, a large scraping sound originates from the blower wheel of the air conditioning system.

Blower wheels are attached to the shaft of blower motors in a commercial air conditioning system. If the attachment between the wheel and the shaft becomes loose, blower wheels will often collide with the housing of the blower and produce a scraping sound. The loud scrap may also be produced if the blower wheel suffers breakage.

The Hissing Air Conditioner

Last but not least, commercial air conditioners will often "hiss", which means that there's need for repairs. Hissing sounds from AC units are commonly associated with leakages. Air leaking from the conditioner's ductwork and refrigerant gases escaping from the AC system will often be responsible for the production of hissing sounds by commercial air conditioners.

All it takes to deal with a noisy commercial air conditioner is a keen ear and a call to the HVAC repair contractor.