Noisy air conditioning can become a major distraction in the workplace, and over time, may eventually become so bad that there’s no other option but to switch the system off.
Fundamentally, a well maintained and fault-free air conditioning system should be almost silent running. So, when an air conditioning system has become noisy, and the noises are becoming more frequent or progressively louder, the chances are, the system is in need of a service or may have developed a fault.
The following diagnostic guide covers a range of the most common causes of air conditioning noise and what should be done in order to resolve it.
The guide is split into two sections covering the most common causes of noise from internal air conditioning units and vents located inside a building and noises coming from external air conditioning units, generally located on a building’s exterior.
NOISE FROM INDOOR AIR CONDITIONING UNITS & VENTS
Noise from indoor air conditioning units and vents can be caused by a multitude of issues and in some cases may be part of normal operation, whilst in others can be caused by neglected servicing and maintenance, user interference, or system faults. Listed below are the most common causes of noise from indoor air conditioning units with the most likely answers to decide the best course of action, in order to resolve the problem:
Excess Air Flow from Vents or Louvers (Ducted Systems Only)
Excess airflow is usually the result of poor system design, a miscalculation of the amount of air required, or incorrectly sized ducts or grilles.
The noises caused by excess air passing through an air conditioning systems vents is most often reported as “my air conditioning is making whistling noise”, “my air conditioning is making a whooshing sound”.
Whilst some limited noise from an air conditioning system’s vents can be considered normal, If the noise is overly noticeable or distracting, contact Air Options to discuss the issue further as we can help.
Expansion and Contraction of the Components Inside Internal Units
Owing to the expansion and contraction of components inside of an air conditioning systems indoor units, some limited noise may be part of normal operation.
The noises caused by expansion and contraction inside of an air conditioning systems indoor units are usually reported as a “my air conditioning is making a clicking sound” or “my air conditioning is making a ticking sound” that occurs just after the system is has been switched on or off, or just after the system has switched modes between heating and cooling.
Although some limited noise resulting from expansion and contraction within an air conditioning unit may be considered normal, if it seems that noises are becoming louder, or more frequent, it may be time to contact Air Options to discuss the issue
BS/BC Boxes (VRF & VRV Systems Only)
Depending upon the type of system in operation and proximity to a system’s branch controller or branch selector box (BC/BS box), usually located within the ceiling void, it may be possible to hear a hissing sound from the air conditioning systems pipework just after the unit has been switched on or off, or when the unit switches between modes.
The noises from a BS/BC are almost always reported as “my air conditioning systems pipework is making a hissing sound”
Whilst some limited noise from a BS or BC box is part of normal operation, excess noise may be caused by refrigerant gas leakage or poor system design. If the noises are becoming louder, or more noticeable, contact Air Options to discuss the issue further.
Dirty Evaporator Coils
Over time, a build-up of dirt on the evaporator coils inside of an air conditioning system indoor unit will reduce its efficiency and cause the system to become progressively noisier as the system needs to work harder to compensate.
The noises caused by dirty air conditioning coils usually progress quite slowly but are often reported as “my air conditioning seems lounder than it used to be” or “my air conditioning is making humming sound”.
Dirty air conditioning evaporator coils are generally a result of neglected air conditioning servicing & maintenance. To resolve noises caused by dirty air conditioning coils and heat exchangers, contact Air Options to book a service call.
Failing Evaporator Condensate Drainage Pumps
As they age, air conditioning evaporator condensate drainage pumps can start to become increasingly noisy during normal operation. This is generally caused by wear and tear to the pump’s motor or impeller caused by a build-up of debris inside the pump housing, around the pump’s impeller or general wear and tear of moving parts.
The noises from an air conditioning evaporator drainage pump or condensate pump are usually reported as “my air conditioning is making a gurgling noise” or “my air conditioning is making a clicking sound”, although in some cases are not signs or faults or failure.
Excessively noisy air conditioning condensate pumps are one of the most common causes of air conditioning noise complaints and should never be neglected as they can also lead to air conditioning smells or an air conditioning system leaking water. To resolve noises being caused by a faulty or failing condensate pump, contact Air Options to book a repair call.
Failing Fan Motors (Indoor Units)
As they age, the fan motors found in an air conditioning systems indoor units can become increasingly noisy during normal operation. This is generally caused by wear and tear to the fan motor’s bearings or a build-up of debris between the motor assembly and the fan blades.
The noises caused by a failing fan motor in an air conditioning systems indoor units are usually reported as “my air conditioning seems louder than it used to be” or “my air conditioning is making a whirring noise”.
Failing or faulty fan motors within indoor air conditioning units tend to become progressively noisier over time and may not be particularly apparent at first however, then after a period of time the noise usually becomes more noticeable. To resolve the noises being caused by a faulty air conditioning fan motor in an indoor unit, contact Air Options to book a repair call.
Imbalanced Fan Blades (Indoor Units)
Imbalanced air conditioning fan blades in indoor units are most often the result of mechanical interference caused by foreign objects such as pens being inserted into a systems internal unit, or a build-up of dirt and debris inside the fan’s enclosure.
The noises caused by imbalanced fan blades in an air conditioning systems indoor units are usually reported as “my air conditioning is making a vibrating noise” or items on the wall or in the ceiling are heard vibrating alongside the unit in question.
imbalanced air conditioning fan blades in internal units can become incredibly intrusive and may result in the system needing to be switched off. To resolve the noises caused by imbalanced air conditioning fan blades, contact Air Options to book an engineer repair visit today.
Noise from outdoor air conditioning units can be caused by a multitude of reasons and on many occasions suggest a fault, especially when the noise is noticeable against background noise to the local environment, where it may be causing a breach of HSE or local planning authority stipulations. The most common causes of noise from outdoor air conditioning units are covered off below, and how the resultant sounds are usually reported, with the best course of action to take in order to resolve the problem.
Failing Fan Motors (Outdoor Units)
Exposed to the elements, the fan motors found in an air conditioning systems outdoor units can become increasingly noisy over time. This is generally caused by wear and tear to the fan motor’s bearings or a build-up of debris between the motor assembly and the fan blades. In some cases, we have even seen fan guards damaged and rubbing against moving parts or fan blades.
The noises caused by a failing fan motor in an air conditioning systems outdoor unit is usually reported as “my outdoor air conditioning unit seems louder than it used to be” or “my outdoor air conditioning unit is making an unusual or clattering noise”.
Failing fan motors in outdoor air conditioning units tend to become progressively noisier over time and may not be particularly apparent at first. However, after a period of time, if the noise becomes more noticeable contact Air Options to book a repair call and get the noise resolved.
Imbalanced Fan Blades (Outdoor Units)
Imbalanced fan blades in outdoor air conditioning units are most often the result of mechanical interference caused by foreign objects finding their way into a systems outdoor unit or a build-up of dirt and debris inside the fan’s enclosure.
Imbalanced fan blades in outdoor air conditioning units can become incredibly intrusive and may result in the system needing to be switched off. To resolve the noises caused by imbalanced air conditioning fan blades in an outdoor unit, contact Air Options to book a repair call
Worn Out belts in Air Handling Units (AHU’s)
Worn fan motor belts in central air handling units (AHUs) make a loud squealing noise where the belts become loose, they wear and slip. This often occurs in older style AHU plant utilising belt drive fan motors and pulley systems. More modern air handling plant are generally direct drive without fan belts therefore do not suffer the same maintenance related noise issues over time.
The noises caused by worn out belts in air handling units are almost always reported as “my outdoor air conditioning unit is making a loud squealing noise” and can often be heard via an internal duct carrying the noise to an internal outlet.
Worn out belts in air handlers are almost always a result of neglected, or poor air conditioning servicing & maintenance. To resolve the noises caused by worn out belts in an air handling unit, contact Air Options to book your engineer visit.