Noisy air conditioner

patrick1945

Well-known member
We don't use our AC often but when we do it seems very noisy. I climbed on the roof today and I took off the AC shroud and when the DW turned it on it seemed that the shaft from the motor to the fan seems to have some play. Now it just might be that the vibration over the living room is just louder than we would like.

Any wisdom out there that might educate me?
 

cjhicks

Well-known member
Check for Mud Dobbers Nest on the back of the Fan Blades.
We don't use our AC often but when we do it seems very noisy. I climbed on the roof today and I took off the AC shroud and when the DW turned it on it seemed that the shaft from the motor to the fan seems to have some play. Now it just might be that the vibration over the living room is just louder than we would like.

Any wisdom out there that might educate me?
 

larryanddonnakeever

Past Oklahoma Chapter Leaders (Founding)
You stated there is play in the motor shaft, was this play in and out play or side to side play.. There will be ever so slight end to end play nothing to worry about. There should be no side to side play. Even the slightest movement would indicate bearing problem. That equates to motoe replacement, which is cheaper and easier than bearing replacement, that is if you can find someone to change bearings... What is the age of the A/C... Also do check for Mud Dobbers first... I Have 36 years Htg/ A.C. experience.
Larry Keever
Okla City
 

patrick1945

Well-known member
small movement is in and out and no daubers (dobbers?)

You stated there is play in the motor shaft, was this play in and out play or side to side play.. There will be ever so slight end to end play nothing to worry about. There should be no side to side play. Even the slightest movement would indicate bearing problem. That equates to motoe replacement, which is cheaper and easier than bearing replacement, that is if you can find someone to change bearings... What is the age of the A/C... Also do check for Mud Dobbers first... I Have 36 years Htg/ A.C. experience.
Larry Keever
Okla City
 

hoefler

Well-known member
It is the bypass vent at the air conditioner its self . It lets all the air to blow straight down beneath the the unit and not out the duct work.
 

patrick1945

Well-known member
I am sorry but I don't what the bypass is and it seems like the air-conditioner is getting louder.

It is the bypass vent at the air conditioner its self . It lets all the air to blow straight down beneath the the unit and not out the duct work.
 

Ray LeTourneau

Senior Member - Past Moderator
Patrick, Up on the ceiling where the air conditioner panel is. There is a grate that open and closes for faster cooling of the living room area. This "bypass" allows the air to flow directly down and out of the a/c into the room rather than into the ductwork. If this grate is open, the a/c is a bit noisier. Generally RV rooftop a/c units are a bit noisy. If you feel it's more than normal, your best bet is to have it checked out by a qualified technician. You might even ask a neighboring camper for an opinion..
 

hoefler

Well-known member
With the A/C running, stand underneath it. Do you feel the air coming out of it straight down on you?? If so, the bypass is open. Look at it and you can see one side has a filter in it and one does not. The side that does not have the filter has a slide lever in the middle to close or open it. Slide it shut and all the air will go through the ducts and quite down considerably. Here is a picture of a common one used in Heartland products. The small grill on the left is the Quick Cool vent.
07_QuickCool1.jpg
 

patrick1945

Well-known member
With the A/C running, stand underneath it. Do you feel the air coming out of it straight down on you?? If so, the bypass is open. Look at it and you can see one side has a filter in it and one does not. The side that does not have the filter has a slide lever in the middle to close or open it. Slide it shut and all the air will go through the ducts and quite down considerably. Here is a picture of a common one used in Heartland products. The small grill on the left is the Quick Cool vent.
View attachment 12650

I misunderstood you. That works great but the AC is once again so noisy after "tightening" the fan mounts last week. It cools just fine but the noise is hard to bare.
 

cookie

Administrator
Staff member
Our AC fan is a lot louder on the new rig than it was on the old one. We mostly run the AC fan on low now. Much quieter that way.

Peace
Dave
 

Ray LeTourneau

Senior Member - Past Moderator
From my perspective, the next suggestion is to contact a professional. Take it to a dealer or a mobile RV service guy.
 

grizzlygiant

Well-known member
It has been our experience with all the roof-top ac units we have had over the years that they sound like a helicopter trying to take off from the roof. Same story with the furnace. I wonder why there has been no improvement after all these years????
 

57chevyconvt

Well-known member
One reason for the higher noise level is that all the new Dometic units are made in China and the sheet metal thickness is less than the older US made units. Therefore the fan mounting and overall stenght of design was lost in the shuffle. Remove the top cover of your newer unit and compair it to one of the older US made units and you will see the difference. This is the improvements that 'grizzlygaint' is wondering about.
 
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