Reply
 
Thread Tools Search this Thread Display Modes
 
Old 11-26-2019, 12:58 PM   #1
Guru
 
healhustler's Avatar
 
City: Longboat Key, FL
Country: USA
Vessel Name: Bucky
Vessel Model: Krogen Manatee 36 North Sea
Join Date: Oct 2009
Posts: 4,855
Irritating fan motor resonance!! Help.

The last time anchored out, our genset went down and we got stuck with power-sucking house fans to keep some air flow going in major heat and humidity, so now I’m installing these super quiet (selected especially for that quality) Caframo 12V boat fans. Of course, with boat bulkheads and walls to mount upon, one might as well be mounting them on the bell of a guitar!

This is ridiculous. I’ve got a full inch or foam insulation beneath each fan mount now, and each mounting screw resting in foam washers. I’ve also tried through bolting with foam padded backing plates, but they’re still pretty noisy. Anybody come up with a better way?

Here’s a pick of the fan type. This is with a half inch pad, a half inch pad backing plate, holes oversized so bolts wouldn't touch the wood, and rubber washers on the bolt heads. Still pretty loud on both sides of the bulkhead.
Admiral doesn’t approve.
Attached Thumbnails
Click image for larger version

Name:	E7E31A5C-D82F-4601-94E2-486B2F8B25C6.jpg
Views:	87
Size:	54.9 KB
ID:	96909  
__________________
Advertisement

__________________
Larry

"When life gets hard, eat marshmallows”.
healhustler is offline   Reply With Quote
Old 11-26-2019, 02:18 PM   #2
TF Site Team
 
Larry M's Avatar
 
City: JAX, FL
Country: USA
Vessel Name: Hobo
Vessel Model: Krogen 42-120
Join Date: Nov 2008
Posts: 8,201
Larry: Have you tried a Hella 2 speed Turbo fan? We went through the same think and found the Hella’s to be quieter than the Caframos. We have nine fans on Hobo. I have had to adjust the prop on the shaft occasionally and have also returned a few because the fan blades weren’t balanced but we’re all Hellas now.

https://www.hellamarine.com/en/produ...turbo-fan.html
__________________

Larry M is online now   Reply With Quote
Old 11-26-2019, 02:34 PM   #3
Veteran Member
 
Sidclark's Avatar
 
City: myrtle beach
Country: us
Vessel Name: Jubilee
Vessel Model: Marine Trader 36 Sundeck
Join Date: Jan 2018
Posts: 93
We had six of those fans on our last boat and by constant fiddling you could get them to quieten down for a few hours at most. The problem is they are not balanced and won't hold a balance when you do find that sweet spot. We tried everything too. New blades, repositioning and no dice. Finally, listened to the wife and bought these...

https://www.westmarine.com/buy/cafra...88?recordNum=3

Pricey, but even mounted right by our head in the master cabin, we could still sleep. Wife approved, so that's all there is to say about that!
Sidclark is offline   Reply With Quote
Old 11-26-2019, 03:01 PM   #4
Guru
 
Comodave's Avatar
 
City: Au Gres, MI
Country: US
Vessel Name: Never Say Never
Vessel Model: President 41 DC
Join Date: Jul 2015
Posts: 6,330
We don’t permanently install 12 volt fans. We have 2 Ridgid 18 volt fans that can also run on 120 volts. With a 4 amp battery they will run on low for 2 days. They are deadly quiet unless you run them on high. They have a knob that adjusts the fan speed to what ever you like. And they come with a lifetime service plan. And they don’t run the house batteries down.
__________________
Boat Nut:
If you are one there is no explanation necessary.
If you aren’t one, there is no explanation possible.
Comodave is offline   Reply With Quote
Old 11-26-2019, 04:53 PM   #5
Guru
 
Xsbank's Avatar
 
City: Pender Harbour, BC
Country: Canada
Vessel Name: Gwaii Haanas
Vessel Model: Custom Aluminum 52
Join Date: Sep 2013
Posts: 3,356
24 volt fans...
__________________
Don't believe everything that you think.
Xsbank is offline   Reply With Quote
Old 11-26-2019, 05:51 PM   #6
Guru
 
Woodland Hills's Avatar
 
City: Jacksonville
Country: USA
Vessel Name: Alzero
Vessel Model: Hatteras 63' CPMY
Join Date: Apr 2017
Posts: 927
Quote:
Originally Posted by Sidclark View Post
We had six of those fans on our last boat and by constant fiddling you could get them to quieten down for a few hours at most. The problem is they are not balanced and won't hold a balance when you do find that sweet spot. We tried everything too. New blades, repositioning and no dice. Finally, listened to the wife and bought these...

https://www.westmarine.com/buy/cafra...88?recordNum=3

Pricey, but even mounted right by our head in the master cabin, we could still sleep. Wife approved, so that's all there is to say about that!
We have 6 of those onboard, one for each berth. Although they are 24v we have been running them at 32v with no issue.
Woodland Hills is online now   Reply With Quote
Old 11-27-2019, 07:17 AM   #7
FF
Guru
 
FF's Avatar
 
Join Date: Oct 2007
Posts: 19,920
So called computer fans rated at 24V are very quiet when operated on 12v.

We have Dorade vents and cap them with 6 inch plastic deck plates.

As the computer fans are not reversible purchasing a (2) 12v units allows air to be sucked in or blown out and a 24V unit for sleeping allows rapid R&R to get just the noise and air volume / direction as desired.
FF is offline   Reply With Quote
Old 11-28-2019, 08:16 PM   #8
Senior Member
 
City: Hervey Bay
Country: Australia
Join Date: Nov 2016
Posts: 112
You may find that increasing the mass of the mount (sheet lead, or a bit of SS plate) may damp out the resonance.
D.Duck44 is offline   Reply With Quote
Old 11-28-2019, 10:03 PM   #9
TF Site Team
 
FlyWright's Avatar
 
City: California Delta and SF Bay
Country: Sacramento, CA, USA (boat in Vallejo)
Vessel Name: FlyWright
Vessel Model: Marshall Californian 34 LRC
Join Date: Apr 2008
Posts: 12,539
Very timely post!

I recently mounted a 2 inch Harbor Freight magnet (painted white except for the mag surface) onto my Caframo 747 fan so that I could use the fan wherever on the boat I had mounted a 2 inch steel washer. I put these washers in the ceiling in my head headliner near the portlight, on my fwd cabinet to move heat aft and on my hatch frame to facilitate summer air circulation.

The head location in the headliner makes a racket like a banjo so I'm thinking of mounting the washer on a 2 inch rubber or firm foam mount washer. I'm hoping to isolate the vibes and noise.

Maybe a foam insulator will help in your situation in addition to the rubber washers. I figure something needs to absorb all that high freq vibe energy.
__________________
My boat is my ark. It's my mobile treehouse and my floating fishing cabin. It's my retreat and my respite. Everyday I thank God I have a boat! -Al

@DeltaBridges - 25 Delta Bridges in 25 Days
FlyWright is online now   Reply With Quote
Old 11-29-2019, 08:53 AM   #10
Senior Member
 
Haylands's Avatar
 
City: Yorkshire
Country: England
Vessel Name: Barefoot Lady
Vessel Model: 1976 Hatteras 42LRC Mk1
Join Date: Nov 2015
Posts: 148
We have one and I found it was better solidly fixed rather than isolated, then the mass it is fixed to works as a damper as well.... Worth a try...!
__________________
Pete & Deb
Haylands is offline   Reply With Quote
Old 11-29-2019, 02:03 PM   #11
Guru
 
Nomad Willy's Avatar
 
City: Concrete Washington State
Country: USA
Vessel Name: Willy
Vessel Model: Willard Nomad 30'
Join Date: Oct 2007
Posts: 16,244
The fan shakes something that is resonate at half or double the frequency of the fan.
Attach the fan closer to a corner or bulkhead.
__________________
Eric

North Western Washington State USA
Nomad Willy is offline   Reply With Quote
Old 11-30-2019, 12:32 AM   #12
Guru
 
healhustler's Avatar
 
City: Longboat Key, FL
Country: USA
Vessel Name: Bucky
Vessel Model: Krogen Manatee 36 North Sea
Join Date: Oct 2009
Posts: 4,855
Quote:
Originally Posted by Larry M View Post
Larry: Have you tried a Hella 2 speed Turbo fan? We went through the same think and found the Hella’s to be quieter than the Caframos. We have nine fans on Hobo. I have had to adjust the prop on the shaft occasionally and have also returned a few because the fan blades weren’t balanced but we’re all Hellas now.

https://www.hellamarine.com/en/produ...turbo-fan.html
Geeze, Larry....I just removed the original Hella units for the same complaint. I’m trying any and all suggestions here to make sure I covered the bases, but I’m close to throwing in the towel and spending another 10 bucks each on pro designed vibration dampers.

I began with mounting direct to the bulkhead, then half inch foam, then half inch front and back, and now it’s one inch front and half inch back with holes oversized and rubber washers. Next I’ll add a SS plate and corner mounting. These were the quietest units we tested at the display in West Marine, but of course, they aren’t mounted to wooden bulkheads there.
__________________
Larry

"When life gets hard, eat marshmallows”.
healhustler is offline   Reply With Quote
Old 11-30-2019, 08:32 AM   #13
Guru
 
OldDan1943's Avatar
 
City: Aventura FL
Country: USA
Vessel Name: Kinja
Vessel Model: American Tug 34 #116
Join Date: Oct 2017
Posts: 4,497
I think I have 5X12vt West Marine fans. I leave them on 24 hrs a day. My house mouse shuts off one in the stateroom, I tun it back on SMIRK
I do not find the noise level offensive but then, I am hard of hearing.
I do consider the fans a disposable item and always carry 3 spares. I replace them every 3 or 4 years.
__________________
Did Noah have a get home-engine?
OldDan1943 is offline   Reply With Quote
Old 11-30-2019, 11:42 AM   #14
Guru
 
Comodave's Avatar
 
City: Au Gres, MI
Country: US
Vessel Name: Never Say Never
Vessel Model: President 41 DC
Join Date: Jul 2015
Posts: 6,330
Guys, all the issues you are referring to are solved with the Ridgid fan I referenced above, quiet, moves way more air than the small 12 volt fans and doesn’t resonate. At the dock I can use an extension cord to power them off 120 volt and on the hook I can use the 18 volt batteries and not run down the house batteries. And you can take them off the boat if you need a fan elsewhere. I also carry it into the engine room when I am working there. One of them pretty much follows me wherever I am working.
__________________
Boat Nut:
If you are one there is no explanation necessary.
If you aren’t one, there is no explanation possible.
Comodave is offline   Reply With Quote
Old 11-30-2019, 02:21 PM   #15
Guru
 
healhustler's Avatar
 
City: Longboat Key, FL
Country: USA
Vessel Name: Bucky
Vessel Model: Krogen Manatee 36 North Sea
Join Date: Oct 2009
Posts: 4,855
Quote:
Originally Posted by Comodave View Post
Guys, all the issues you are referring to are solved with the Ridgid fan I referenced above, quiet, moves way more air than the small 12 volt fans and doesn’t resonate. At the dock I can use an extension cord to power them off 120 volt and on the hook I can use the 18 volt batteries and not run down the house batteries. And you can take them off the boat if you need a fan elsewhere. I also carry it into the engine room when I am working there. One of them pretty much follows me wherever I am working.
Yes, picked up one to try yesterday at Black Friday sale. At the very least, I’ll be using it when down under the galley for machinery service. Also great for bilge painting ventilation. Ugly, but then one can’t have everything can we. Maybe I can redo the interior upholstery on orange & black!
__________________
Larry

"When life gets hard, eat marshmallows”.
healhustler is offline   Reply With Quote
Old 11-30-2019, 02:30 PM   #16
Guru
 
Comodave's Avatar
 
City: Au Gres, MI
Country: US
Vessel Name: Never Say Never
Vessel Model: President 41 DC
Join Date: Jul 2015
Posts: 6,330
We love ours. We have 2. Keep one by my recliner in the house for when it gets too hot. And keep the other on the boat full time. When we are going to go overnight on the boat we take both of them. It is really handy to be able to move them around without power cords.
__________________
Boat Nut:
If you are one there is no explanation necessary.
If you aren’t one, there is no explanation possible.
Comodave is offline   Reply With Quote
Old 12-06-2019, 02:06 PM   #17
Member
 
City: Shady Side, Md
Country: U.S.A.
Join Date: Jul 2019
Posts: 8
Quiet fans

I’ve found that larger fans, 10-12”, with at least 2 speeds, are much quieter. Most can either sit on a flat surface or u can hang them.
The O2 cool fans are quiet, cheap, and most run on 12v, batteries, or 110v if you have an inverter or generator.

For example: https://www.amazon.com/gp/aw/d/B00ATSHJ1Q/ref=ox_sc_saved_image_5?smid=AJ5IBHU2RIN49&psc=1
altinr is offline   Reply With Quote
Old 12-08-2019, 06:33 PM   #18
Guru
 
fryedaze's Avatar
 
City: Solomons Island Md
Country: USA
Vessel Name: Fryedaze
Vessel Model: MC 42 (Overseas Co) Monk 42
Join Date: Sep 2011
Posts: 1,320
Larry we installed 4 of those fans. Two of the four vibrate bad in high speed but are not bad at slow. The other two are great in high or low. I called the company and they sent me a new blade. It didn't make any difference. I think the problem is the lack of a small bearing where the shaft comes through the housing. A simple plastic sleeve on the shaft should eliminate the wobble. That not is on my long list.
__________________
Dave Frye
Fryedaze, MC 42 (Monk 42') 1989 Overseas Co
http://mvfryedaze.blogspot.com/
fryedaze is offline   Reply With Quote
Old 12-08-2019, 10:55 PM   #19
Guru
 
healhustler's Avatar
 
City: Longboat Key, FL
Country: USA
Vessel Name: Bucky
Vessel Model: Krogen Manatee 36 North Sea
Join Date: Oct 2009
Posts: 4,855
Admiral says install two in each cabin, one in galley and one in the head. After failing with several insulating ideas, I tried screwing a 7/8” cork cored, elastomeric pad to the wall, then counter sunk two bolts into the back of 2nd identical pad to secure the fan with rubber washers and nuts, then mounted the pad with the fan to the pad on the wall with perimeter screws, separating the pads with water hose washers (which also leaves a vibration/compression air space). This way, both the fan and the mounting bolts can vibrate without a cooperative resonance path to the wall. So far, the fix comes to about $2 each unit.

I am trying one now but will also try each of the eight units we purchased before final installation, if for nothing else, to see if some are better balanced as Dave noted above. We’re also comparing one of the units Commodave talked about for sound and air movement. Likely, that style will be preferred for sleeping.
__________________
Larry

"When life gets hard, eat marshmallows”.
healhustler is offline   Reply With Quote
Old 12-08-2019, 10:59 PM   #20
TF Site Team
 
FlyWright's Avatar
 
City: California Delta and SF Bay
Country: Sacramento, CA, USA (boat in Vallejo)
Vessel Name: FlyWright
Vessel Model: Marshall Californian 34 LRC
Join Date: Apr 2008
Posts: 12,539
You'll have so many fans aboard maybe you can point them all aft when underway to help your speed, Larry.
__________________

__________________
My boat is my ark. It's my mobile treehouse and my floating fishing cabin. It's my retreat and my respite. Everyday I thank God I have a boat! -Al

@DeltaBridges - 25 Delta Bridges in 25 Days
FlyWright is online now   Reply With Quote
Reply

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





All times are GMT -5. The time now is 12:07 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012
×