Reply
 
Thread Tools Search this Thread Display Modes
 
Old 06-22-2015, 09:52 AM   #1
Rivet Master
 
aquinob's Avatar
 
1973 27' Overlander
Portsmouth , Virginia
Join Date: Jun 2012
Posts: 776
Newer Dometic AC is one noisy bugger, any ideas to quiet it down?

Just got back from the campground yesterday. Temps were in the 90's and the site did not have any shade. AC worked continuously, during the day kept the temps inside in the upper 70's give or take. At night it ran in auto mode and would cycle maybe once every half hour for about 5 mins, but when it turns on, you know about it. In general it is a noisy bugger inside and is quite intrusive. The last night there, I left the fan setting on low rather than auto so the fan ran all night which makes it more like white noise which you can get used to and ignore rather than the abrupt start and stop.

So the real question I have is this, what can you do to reduce the transmitted noise and vibrations of these units into the big sounding board that is the shell of the trailer? This ac transmits so much vibration that things like the grates on stove vibrate and buzz. It has the standard rubber mount pad on the bottom of the unit that seals it up on the outside. Maybe if I loosen up on the hold down bolts that would help a bit? It's really obnoxious after you have been listening to it awhile, and is so nice when its off and things are much quieter. Anybody have a reasonable practical solution that might work?
__________________

__________________
Bob

Ongoing adventures at:
http://1973overlander.blogspot.com/
aquinob is offline   Reply With Quote
Old 06-22-2015, 09:58 AM   #2
1987 Avion 34W owner
 
PaulnGina's Avatar
 
Vintage Kin Owner
Good Ol' , USA
Join Date: Mar 2014
Posts: 1,889
If the foam seal is in good shape, I think it would be a good idea to try loosening the bolts a bit to see if that makes a difference. Also, if you can do it, I'd take the cover off of the roof unit and watch it run. Maybe there's some kind of problem with the spinning parts that are making an out-of-balance condition? Loosening the bolts might help, but I'm thinking that will just be masking the real source of the problem.
__________________

__________________
"Long lay the world in sin and error pining
Till He appeared and the soul felt its worth"
1987 Avion 34W
1995 Ford F250 7.3L PowerStroke
PaulnGina is offline   Reply With Quote
Old 06-22-2015, 10:08 AM   #3
Rivet Master
 
Landrum's Avatar
 
2014 25' FB International
Little Rock , Arkansas
Join Date: Jul 2012
Posts: 591
Our AC is definitely loud. The newer ducted AC units are suppose to much better


Sent from my iPhone using Airstream Forums
__________________
Landrum is offline   Reply With Quote
Old 06-22-2015, 10:11 AM   #4
Rivet Master
 
Landrum's Avatar
 
2014 25' FB International
Little Rock , Arkansas
Join Date: Jul 2012
Posts: 591
Well that wasn't suppose to post.

Our unit is loud as well, but it doesn't cause other components in the Airstream to vibrate. Could be something wrong with your AC? That said we prefer to sleep with white noise and always leave the fan on low. Therefore we don't notice the compressor turning on and off.


Sent from my iPhone using Airstream Forums
__________________
Landrum is offline   Reply With Quote
Old 06-22-2015, 10:20 AM   #5
Rivet Master
 
HowieE's Avatar
 
1991 34' Excella
Princeton , New Jersey
Join Date: Aug 2003
Posts: 6,813
Images: 12
Vibration from the unit are more likely to transmit through the bolts than the seal. I would remove the bolts one at a time and put a metal fender washer and urethane bushing on the bolt before replacing them. Yo may have to get longer bolts to accommodate a bushing that will attenuate the mechanical transmission.

While the bolts are out remove the filter run the unit and feel up into the unit to see if there is noticeable vibration. Do this test with just the fan running and then with the compressor running. This may give some info as to the source.
__________________
WBCCI 12156 AIR 3144 WACHUNG TAC NJ6
2004 Excursion 4x4
1991 34 ft. Excella +220,000 miles, new laminated flooring, new upholstery, new 3200 lbs axles

HowieE is offline   Reply With Quote
Old 06-22-2015, 11:24 AM   #6
Rivet Master
 
aquinob's Avatar
 
1973 27' Overlander
Portsmouth , Virginia
Join Date: Jun 2012
Posts: 776
The unit was bought last year as used but was essentially new, never used. The foam gasket was all in perfect shape, but it has always been on the noisy side, especially when the compressor was running. It's one of the low profile units, 13.5K BTU, and I've read some that folks find them to be noiser than the older style units.

I think what I will try first is to pull the bottom cover back off and loosen up on the four hold down bolts till I can see some expansion of the foam and then see how it sounds. I may go ahead and see if I can order some sort of acoustic isolation foam or material and judiciously use it to help isolate the bolts that may be transmitting much of the vibration. With this thing running, everything seems to buzz in harmony, including the inside cover, the stove grates and a loose metal part in the screen door. I'm not sure it will ever be in the realm of "quiet" but hopefully will be less intrusive.
__________________
Bob

Ongoing adventures at:
http://1973overlander.blogspot.com/
aquinob is offline   Reply With Quote
Old 06-22-2015, 11:36 AM   #7
Rivet Master
Commercial Member
 
lewster's Avatar
 
Vintage Kin Owner
Naples, FL , Hood River, OR
Join Date: Dec 2005
Posts: 7,281
When Dometic ships an auxiliary drip kit (that's the one with the catch cups for the condensate), they include an additional foam gasket. There should be 2 of these on a penguin unit, along with additional foam pieces included in the kit.

For some unknown reason, Airstream insists on using just one gasket. This positions the drain cups directly on the roof, and they provide an additional hard surface that will transmit the vibrations.

If it were my trailer, I would remove the A/C unit from the roof and replace the gasket with a new one. I would then re-install the drain kit according to Dometic's instructions, including the second gasket.

The addition of urethane bushings and fender washers might also help with the vibration problem.

Those long bolts are 1/4 - 20 and should have sufficient length for the bushings, as the Airstream roof is only 2" thick.


Lew Farber
RVIA/RVDA Nationally Certified Master Tech
Master Tech Energy Systems, Inc.
AM Solar Certified Installation Center
Lifeline Batteries**Magnum Inverters
541-490-6357
__________________
Lew Farber...ABYC Certified Master Marine Electrician...RVIA Certified Master Tech ...AM Solar Authorized Installation Center...AIRSTREAM Solar & Electrical Specialist...Micro Air 'Easy Start' Sales and Installations
lewster is offline   Reply With Quote
Old 06-22-2015, 11:40 AM   #8
65will
 
65will's Avatar
 
1969 25' Tradewind
Greenwich , New York
Join Date: May 2012
Posts: 37
They sure are noisy!

I have the same unit, I installed it on my 69 Trade Wind. We just got back from a 2 week trip where we used it almost all the time. It is queit outside the trailer but very loud in. I have a little vibration, but not as bad as yours. If you touch the walls when the unit is running you can feel it. I will be very intrested to see what you come up with.
__________________
65will is offline   Reply With Quote
Old 06-22-2015, 12:04 PM   #9
Rivet Master
 
daveswenson's Avatar
 
2012 28' International
Issaquah , Washington
Join Date: Sep 2012
Posts: 767
In my trailer there was a lot of noise from the corners on the inner unit where it contacts the inner skin. I slid some strips of thin cardboard into the gap at the corners. It lessens the rattle.
__________________
Dave

2014 Ram 2500 CTD
Pro Pride
Centramatics
daveswenson is offline   Reply With Quote
Old 06-22-2015, 12:06 PM   #10
Rivet Master
 
1996 25' Excella
Tillsonburg , Ontario
Join Date: Aug 2014
Posts: 787
My first move woulpd be to lift the ccover and then inspect the unit while running to see whet
her there is somthing obvious. The compressor is the likely culprit, but maybe it is just knocking against he frame. Maybe during the install the frame got twisted or the compressor mount is loose.
jcw
__________________
JCWDCW is offline   Reply With Quote
Old 06-22-2015, 12:27 PM   #11
Richard

 
2006 30' Classic S/O
Merced , California
Join Date: Apr 2006
Posts: 78
Lewster is so correct on this issue. I had the same problem starting with a new 2006 with 13.5 w heat pump (so don't blame this on new models). Live in California so had to upgrade to 15K. The dealer that changed the unit installed it properly with two gaskets. Still have the same trailer. Problem solved.
__________________
kleimanr is offline   Reply With Quote
Old 06-22-2015, 12:35 PM   #12
Rivet Master
 
Wayne&Sam's Avatar
 
2014 25' Flying Cloud
Cuddebackville , New York
Join Date: May 2007
Posts: 3,100
Images: 21
Quote:
Originally Posted by lewster View Post
For some unknown reason, Airstream insists on using just one gasket. This positions the drain cups directly on the roof, and they provide an additional hard surface that will transmit the vibrations.
As a marketing technique to sell new ducted Airstreams?
__________________
2014 25' Flying Cloud Rear Twin
2012 Dodge Durango Hemi/AWD
Wayne&Sam is online now   Reply With Quote
Old 06-22-2015, 01:01 PM   #13
Rivet Master
 
A W Warn's Avatar
 
2000 25' Safari
1999 34' Excella
Davidson County, NC , Highlands County, FL
Join Date: Aug 2006
Posts: 2,571
Quote:
Originally Posted by aquinob View Post
Just got back from the campground yesterday. Temps were in the 90's and the site did not have any shade. AC worked continuously, during the day kept the temps inside in the upper 70's give or take. At night it ran in auto mode and would cycle maybe once every half hour for about 5 mins, but when it turns on, you know about it. In general it is a noisy bugger inside and is quite intrusive. The last night there, I left the fan setting on low rather than auto so the fan ran all night which makes it more like white noise which you can get used to and ignore rather than the abrupt start and stop.

So the real question I have is this, what can you do to reduce the transmitted noise and vibrations of these units into the big sounding board that is the shell of the trailer? This ac transmits so much vibration that things like the grates on stove vibrate and buzz. It has the standard rubber mount pad on the bottom of the unit that seals it up on the outside. Maybe if I loosen up on the hold down bolts that would help a bit? It's really obnoxious after you have been listening to it awhile, and is so nice when its off and things are much quieter. Anybody have a reasonable practical solution that might work?
Your '73 model has more curve to the roof than wide body trailers so that could be a contributing factor. The gasket will be compressed more near the center and less nearer the sides. I think Lewster gave you the best advice, two gaskets.

The '73 that I had several years ago did not have a frame around the A/C roof opening when I purchased it. A technician from ODM added wood blocking when he changed out the A/C unit. That allowed less movement of the unit and helped make it quieter. You might want to check yours to see if it has blocking.

I don't have the same A/C unit as you have now, but I had a vibration problem in my 2000 Safari. When I replaced the pan a few years ago I realized the bolts had loosened as the gasket compressed, from aging over the years I assume. The A/C unit actually could/did move as the compressor cycled. When I replaced the pan and foam gasket, then tightened bolts correctly it was much improved.
__________________
Alan
2014 Silverado 1500 Crew Cab 5.3L maximum trailering package (yes, I'm towing the 34')
A W Warn is offline   Reply With Quote
Old 06-22-2015, 01:18 PM   #14
Site Team
 
, Minnesota
Join Date: Aug 2003
Posts: 6,940
Images: 59
I just replaced an older (5 years) Penguin with the newer Penguin II. I find it to be slightly quieter than the older Penguin. I used the Lewster mounting method.
__________________

__________________
markdoane is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Goin' down, down, down... Aironius Axles 12 08-23-2014 09:09 AM
One tank down and one to go! bullydogsmom Cleaning, Stripping & Polishing 6 06-05-2009 09:43 AM
any ideas??? Dometic to freon conversion? bookman Refrigerators 8 09-20-2008 02:13 PM
One down, one to go.... Pick Axles 3 01-13-2003 11:31 AM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 02:50 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.