Why Is My Central Air Conditioner So Noisy?

Everyone enjoys the cool, dry comfort that central air conditioner or heat pump system brings to a home, but if you have a traditional split system, sometimes the noise from the outdoor unit (called a condenser) can be annoyingly loud.  If the condenser has been located outside of a bedroom, it can even interfere with your sleep.

All condensers make some noise although some brands are quieter than others.  If you have an older, inefficient unit this may be a good time to upgrade to a quiet new energy efficient system.  Depending on your old system and how often you run your air conditioner, you may be surprised how quickly the savings on your energy bills will cover the cost of the new unit.  Meanwhile, you will be enjoying your quiet new air conditioner.

If a new central air conditioning system is not in the budget for this year, have your noisy air conditioner serviced and inspected by your HVAC technician.  You could have a bent fan blade striking the housing or a piece of the sheet metal housing could be loose and vibrating.

If the condenser checks out, you may need to investigate other options such as relocating the condenser to a less obtrusive spot or building an enclosure around the unit.  If you opt for the enclosure, be sure to allow plenty of space around the condenser for adequate ventilation and so it can be serviced.  A partial enclosure that is open on the side away from the house can often do the trick.

Quieting a Noisy HVAC Unit

Is the noise from your air conditioning compressor unit interfering with your sleep?   All compressors make noise, but some seem to be much louder than others.  If you have one of these noisy beasts, here are a few ideas to help hold down the racket and let you get a good nights sleep.

First, have the unit inspected and serviced by and experienced HVAC technician.  Regular residential HVAC service and repair will keep the unit in top operating condition.It is possible that the noise is a symptom of a bigger problem.  A broken or bent fan blade or loose piece of sheet metal can cause the compressor to rattle and shake.  Also, sometimes just repositioning the unit will cut down on the vibration and noise. 

If it is still too noisy, ask the HVAC technician about moving the unit to a better, more distant location.  This will involve some expense, but it’s not a difficult job for a good HVAC contractor.  Moving the unit a little further away from your window will significantly reduce the noise level in your bedroom.  Moving it around a corner to another side of the house or into an alcove will reduce the noise even further.

If there is not a good place to relocate the unit, you can always build an enclosure for it.  Be sure that the enclosure is either removable or large enough to allow access to service the unit.  It is also important to allow sufficient air flow for the unit to operate properly.  Ask the HVAC technician what the minimum clearance around the unit should be.  Also, leave one side open or covered with lattice or some other design that allows plenty of air to circulate around the unit.