• Mobile App For Android Now Online!

    Download it here. The app is searchable in the Google Play Store under Sailboat Owners.

    Sorry iPhone/iPad users, we are still waiting on Apple. :(

    Click the X in the upper right corner to make this go away

Blower Muffler

Jan 4, 2006
3,029
Hunter 310 West Vancouver, B.C.
Has anyone installed a bilge exhaust fan in their engine compartment ? Now before you label me an idiot or worse, this is strictly for cooling.

On our H310, the engine is stored in a Nike shoe box and the temperature in there hits 150 deg. F which is not ideal for either the engine air supply nor as cooling air for the alternator.



Through extensive consultation with posters on this site, I finally wound up using corrugated aluminum dryer exhaust hose. Solid, flexible, low frictional pressure drop, very pretty





and drops the housing internal temperature from 150 deg. F to 85 deg. F. The only problem is that the noise is excruciating, intolerable, unbearable, insufferable, painful and worse than rap music ............ like a thousand finger nails drawn over a chalkboard all at once. The discharge is under the helm seat and generates enough noise to drown out the engine. The fan is a 3" Shurflo Yellow Tail Blower turning over at 10,000 RPM. Small wonder its noisy.



What I'm looking for is is a relatively small muffler which will reduce the noise and yet not significantly reduce the air flow.

Thanks as always for your ideas and suggestions.
 
Sep 25, 2008
1,059
CS 30 Toronto
Your problem is the axial blower. They are noicy cus the small cross section for the air to flow thru. Get a squiral cage type with lower rpm. Muffler wont do a thing for you.
 
May 16, 2007
1,509
Boatless ! 26 Ottawa, Ontario
Nice installation Ralph.
We have a blower on our boat to remove engine heat. It was an option installed by Hunter. They are using the orange hose in the photo. It appears to use a regular bilge blower and exhausts out a chrome clam shell on transom. We can not hear it running with engine going. We also have fresh air intake for the engine that Hunter installed. I don't know if you need that with a blower removing air from the engine room ? Bob
 

Attachments

Feb 10, 2004
3,308
Hunter 40.5 East Greenwich, RI
I have simple in-line bilge blowers in both my engine compartment and in my generator compartment. Both exhaust at the stern through cabin ventilation ports that I hyjacked for the purpose. I cannot hear either fan when the generator or engine is running, and I can only hear the generator fan while I am pre-heating. I don't have solid data on the temperature reduction, but I know that the engine compartment drops from 175+ to about 130 F.
 
Jan 22, 2008
7,728
Beneteau 323 Annapolis MD
I wonder if that much suction is creating a bit of vacuum in the engine room, maybe causing a whistling noise sucking air in? 2c worth.
 
Jan 4, 2006
3,029
Hunter 310 West Vancouver, B.C.
It appears to use a regular bilge blower and exhausts out a chrome clam shell on transom. b
Bob, you have my undivided attention. In you photo, I presume the white cylindrical object is the exhaust fan. Can you please supply a manufacturer's name for this as this may be a much quieter fan. As mentioned, mine is the Yellowtail Shurflo which can also be used as an air raid siren.
 

Attachments

higgs

.
Aug 24, 2005
3,450
Nassau 34 Olcott, NY
I do have a blower in my bilge. I figured it was there for cooling, dropping a thermometer in there out of curiosity, I don't see a difference whether it is running or not.
 
Feb 6, 1998
11,272
Canadian Sailcraft 36T Casco Bay, ME
Bob, you have my undivided attention. In you photo, I presume the white cylindrical object is the exhaust fan. Can you please supply a manufacturer's name for this as this may be a much quieter fan. As mentioned, mine is the Yellowtail Shurflo which can also be used as an air raid siren.
Ralph,

As an experiment try isolating the fan motor from the vessel. Simply set it on some foam temporarily and see if it quiets down. I have had a few that transmitted a resonance through the hull that was extremely annoying. I then mounted them to 1/2 rubber and made an isolation mount.

Anyone who's ever owned an Espar or Webasto and not had the fuel pump properly isolated, using the rubber mount, will understand this.. It may help, may not but worth a try..

Our blower fan is pretty quiet and I have to reach my hand behind the outlet to tell if it is on....

You may also want to try a DC motor speed controller they have come way down in price in recent years and you may not need the full CFM rating.......

PS The one in that photo looks like a DetMar....
 
Nov 24, 2012
586
Bob, you have my undivided attention. In you photo, I presume the white cylindrical object is the exhaust fan. Can you please supply a manufacturer's name for this as this may be a much quieter fan. As mentioned, mine is the Yellowtail Shurflo which can also be used as an air raid siren.
This has been a standard on B boats for many years. I had one go bad - very noisy. Installed a new one - ran fine after very quiet. We do have it mounted on rubber dampers mounted on a wood panel. Also use a 3 or 4" flex hose forgot which. Both are standard products at West.

Potential problems - bad motor, mounting exacerbates the noise, vibration in the aluminum hose.
 
Jan 3, 2009
821
Marine Trader 34 Where Ever I am
We've used those vent hoses on the boat for a couple of different uses. In time, every one of them has split from the vibration of the fan. Chuck
 
Oct 2, 2006
1,517
Jboat J24 commack
I have a Jabsco squirrel cage blower which is pretty quite

The 105 CFM unit seems to move plenty of air even on my A4 gasoline motor and it makes a nice hand warmer on those long cold motoring days :
 
May 16, 2007
1,509
Boatless ! 26 Ottawa, Ontario
Ralph, sorry for the delay we were away from the boat. I just took a shot of the label on our blower see below.
It seems to be not bad for noise, we have used it with the engine stopped to cool down the cabin after a long run if it is a real hot day.
It is mounted under the aft berth to a plywood support. I have seen pumps rubber mounted by bolting them to a piece of rubber hose that extends about 3" on each side of the pump body, then bolting the hose ends to a hard spot. It seems to filter out most of the vibration that can get into the hull/bulkhead and radiate all over the place.
Regards, Bob
 

Attachments

Sep 15, 2009
6,241
S2 9.2a Fairhope Al
We'll it seems Mainesail was dead on with the make of that blower. Now for his reward he gets a free read on SBO all day long regards woody
 
Jan 4, 2006
3,029
Hunter 310 West Vancouver, B.C.
Thanks to One and All ................

.............. for your well thought out replies.

Ralph,

As an experiment try isolating the fan motor from the vessel. Simply set it on some foam temporarily and see if it quiets down. I have had a few that transmitted a resonance through the hull that was extremely annoying. I then mounted them to 1/2 rubber and made an isolation mount.
Definitely will try this first as it's the simplest = cheapest way to approach the problem.

Your problem is the axial blower. They are noicy cus the small cross section for the air to flow thru. Get a squiral cage type with lower rpm. Muffler wont do a thing for you.
I agree that it's difficult to deal with the noise (after the fact) from the 10,000 RPM. The squirrel cage with the lower RPM will probably be the best solution. Unfortunately a tight fit in a compact space due to the hose configuration.

Nice installation Ralph.
We have a blower on our boat to remove engine heat. It was an option installed by Hunter. They are using the orange hose in the photo. It appears to use a regular bilge blower and exhausts out a chrome clam shell on transom. We can not hear it running with engine going. We also have fresh air intake for the engine that Hunter installed. I don't know if you need that with a blower removing air from the engine room ? Bob
This just may be worth trying as a inexpensive experiment as E-bay has these blowers for $25.00. DetMar may well be quieter than ShurFlo.


Ralph, I think that is a bow thruster you have pictured ! :doh:
Ron, you're probably right, it definitely sounds like a bow thruster out of water.

I will post to let you know the outcome.