Loud Condenser Fan

[luca]

Hello All,

My mother in law has a very old Amana Heat Pump/AC unit approx 25 years old. The condenser (the outside unit if I got that wrong) fan motor was shot so we had it replaced with a universal motor. We noticed it was louder then before but assumed it was ok, by louder I mean the fan seems to make more noise (wind noise). It is on the side of the house so it doesn't bother us. Her neighbor logged a compliant to the city for the noise. We are at 63DBa instead of 50DBa at the property limit. Since this unit is so old relatively few want to come back once they see it. We have had two come by and both were not willing to do much on the unit stating it is old and parts are not available. Although it got a clean bill when the first HVAC tech changed the motor, he checked pressure and whatnot and said all was good. The unit does cool the house nicely.

I would like to see if any off you think that the fan is defective. I say this because they had a hell of time getting it off and had to use a puller. I wonder if it distorted the fan, i noticed it had more vibration then before. Could it also be it is spinning faster than before? Do they make quieter fan blades? Without the FAN running the compressor purrs nicely and is not making noise.

As you have guessed I did do some troubleshooting myself, but did not do any of the repairs.

Thanks for you help

Luca

[Admin]

In Ottawa we follow Noise By-law No. 2004 - 253(4),

No person shall use or operate or cause to be used or operated any air conditioner, heat pump, compressor, condenser, chiller, cooling tower or similar device, the noise from which has a level greater than 50 dBA when measured at the point of reception.

You could advise bylaw that the heat pump most likely existed before the bylaw, in which case the heat pump should be grandfathered.

Have you checked if there are multiple speeds on the new fan motor?  You may be able to use a lower speed if there's one available.  The replacement motor probably has a higher horse power rating.

It's possible the fan blades are off balance, but from what you describe it sounds like the new fan motor is just moving more air.

I have seen the rotation set incorrectly which causes the fan to spin the wrong way.  It caused some noise but the AC still worked and no one had noticed it was spinning the wrong way for years.

[luca]

Hi Admin

The rotation is correct as it blows the same as before. I think your correct about it pushing more air, I also suspect the motor is probably stronger then the previous one. This will also end making that motor go bad sooner. I will see if I can call Amana client support and see if they could at least tell me what HP rating and RPM it used to be.

Good point on the Grandfathered clause although good neighbors are better than bitter ones.

Thanks

Luca

[slo-115]

likely the tech that replaced the motor was rough getting the old blades off and bent or slightly damaged them. It can be tough getting the old blades off. You will have difficulty finding new blades, you may find something close online. Call the first guy back, he now inherits this problem

[luca]

Curiosity got me looking on the web for the Model Heat Pump she has and surprisingly I found that sears still has some parts for it. To make a long story short the HVAC tech replaced the motor with a 1/3HP instead of a 1/4HP. Not much of a diff but the extra air flow is making way more noise than before and also will kill the new motor. We will have him replace it.

Thanks

Luca