adjusting roof airs

[lbrachfe]

Does anyone possess the wisdom to explain to me any way to make the units quieter ? my fans are noisier than they used to be with a vibrate/rumble but not loud just annoying. Any suggestions on the bolts that hold to roof . Two bolts about ten inches long holding to frame.Can they be adjusted for noise reduction by eliminating vibration and how much and tighter or looser? Have tried just tightening and loosening one with little or no effect but don't want to go too far....Help anyone?

[rheavn]

Larry,
The only thing the hold down bolts do is compress the gasket to keep it from leaking. Adjusting them will not change the vibration noise. I, like you, did try it. Have not taken on the task of going after the fan noise.

Sorry I couldn't be more helpful......................

[lbrachfe]

I kind of thought they only held down the seal. Do you think a product of coils needing to be cleaned could be causing vibratation sounds? Mine have more rumble like aa fan out of true maybe touching the housing? Hope other may chime in with experiences.Thanks Steve....

[encantotom]

i had 3 roof airs in my 90. i actually installed one of them myself (like cut the hole in the roof etc.

like steve said, they are installed so that the bottom plate and the compressor on the top sandwich the roof of the coach and what holds the two together (with the gasket on the roof) is the 4 long bolts from the bottom. those bolts will do nothing for vibration.

the only moving parts are the compressor and the fan. the fan is just a squirrel cage and could get out of round and i believe it is replaceable.

that is going to be a fun one to try and denoise.

tom

[lbrachfe]

As soon as it warms a little here in South Florida to above 45 degrees I will be on the roof pulling the covers and attacking the squirrel cages to spot weld any moving areas or replace as suggested.The noise does seem like it is coming from there and it happened to all three after a real bumpy 100 miles of highway in North Alabama.I am fussy about noises and will solve this eventually and will keep you all posted, but keep any suggestions coming and does anyone have part and source on the fan?

[HoosierDaddy]

Hi Larry,
What is the make ,model # of your A/C's? Some of them have one motor that runs both the condensor and evaporater fans on the same shaft. You may find debris that has collected under the cover. I'd clean it and dab some silicone caulk on the areas that may be vibrating.

[folivier]

Hey Larry, while you're on the roof look for mud daubers in and around your fan in the a/c. The little rascals can seriously throw a fan off balance.

[MarkofSJC]

Just another thought to throw out there. You may want to take a close look at the bearings on the squirrel cages as well. Sometimes just putting some silicone or graphite will make all the difference in the world! (Just think of how long and hard those squirrel cages have been spinning!)

Mark