3

My AC recently (I think, it's pretty new, possible I just didn't notice before) started making a whooshing noise. It sounds kind of like a sudden gust of wind, but it repeats every few seconds. Another way I can think of to describe it: imagine a PC cooler running relatively silent, but still being able to hear it. Now imagine it increasing its RPM noticeably for just around a second. Now imagine it doing this continuously.

It's a Whirlpool split type 12k BTU.

It also doesn't result in air being blown faster but, when you can hear it, if you stand in front of the indoor unit, air stops coming out for like half a second on just one side of the unit. Like the unit "chokes".

Things I've noticed and done:

  • efficiency doesn't seem to be affected, it still cools very well, but the sound is annoying.

  • it only seems to happen on higher temperatures. For example at 24 and 25 C. Any lower and my unit will start blowing out more air as well, which seems to result in a steady stream of air uninterrupted by whooshings.

  • if I lift the front panel, revealing the filters, the phenomenon stops! I thought something might be pushing on the filters, or that it's not closing properly, but I can't see any issues...

  • also, if I remove remove the filter on the offending side, it doesn't happen even with the front panel closed.

  • it doesn't always happen. Sometimes I run it for hours with no annoying sound, other times it starts a few minutes after turning on the AC. Sometimes it stops for a while.

Any ideas? I tried recording the sound but my phone doesn't really allow you to notice it when it occurs. I can try again if you think a recording would help.

IVlad
  • 33
  • 1
  • 1
  • 7

5 Answers5

1

"If I remove remove the filter on the offending side, it doesn't happen."

This tells us that it is an Airflow Issue and the culprit is in the filter mechanics.

I am guessing you recently changed filters - perhaps to a new brand or type. Is the filter installed in the correct direction of Airflow - an Arrow on the side should point the way..

I am thinking your filters are the wrong type. The filter is not allowing enough flow (apparently a tight fit) and as the suction (vacuum) builds up the filter moves and eventually it is in a position to allow more air flow and you get the whooshing sound of air passing either around the filter or surprisingly through it.

You can verify the filter brand and type recommendations of your unit - or compare to non offending side - perhaps non-offending side fits loosely and offending side fits more tightly in the filter slots..??

Ken
  • 5,453
  • 2
  • 18
  • 33
1

My air con (Samsung split system) was making a whooshing sound for the past 12 mths and getting worse. I thought I was pretty good and regular at cleaning my filters but have discovered I'm not as good as I had thought. I was vacuuming them clean but noticed they were still lookinga bit grey so i scrubbed them in hot soapy water and now haven't heard this noise for over a week now. Hopefully, problem solved.

Elsie Doggett
  • 11
  • 2
1

I had this issue with my indoor wall mount unit, after it had been serviced/cleaned. After inspecting it myself, I found out the cleaning technician, did not click the cover back into place properly (in the vent area - where the air exits the unit). This caused the blower fan to intermittently send air through the gap and caused it to occasionally make a sound like a gush of wind. Hope this helps somebody.

Luke
  • 11
  • 1
0

it's water trapped in the back. Tilting it drains the water or at least partially empties the puddle to the point it doesn't "slosh" from the big fan blowing over it. The temp and humidity outside greatly affect the evaporation rate of the condensation, which explains the sporadic nature of your observations, as sometimes the coils will dry before they drip or puddle up.

possible solutions:

  • Keep it a bit tilted, as long as it's secure it will work fine like that
  • Hose out the back really well, it could have a clogged drain channel
  • carefully open the back when noisy, find the puddle, and drill a small hole by it
dandavis
  • 2,262
  • 10
  • 11
0

I believe one of your blower fans or squirl cage blowers being the most common I have seen. Has either had the hub break I have one of these on my desk right now waiting for a new "fan" , this is rare but happens or the set screw has loosened the spring clip or other securing method of locking the fan to the motor and the fan is spinning loose. When you open the chamber there is very little load so the fan spins , close it up and as pressure builds it breaks loose, I think this is the cause of the "whooshing" please look at this possible cause quickly as if it is the cause the free spinning on the motor shaft will damage the fan and the motor, it may work ok but will get out of balance and vibrate. Hope this helps. I apologise I was kind of thinking of this when I commented and got called away and did not finish my thought.

Ed Beal
  • 103,727
  • 4
  • 79
  • 158