Bilge Blower Operation Direction

crazy charlie

Vice Admiral
Joined
May 22, 2003
Messages
5,581
I have 2 bilge blowers in my twin screw Regal.I am replacing both since they seem to be working at half speed.One is bringing air into the bilge and the other is drawing air out.Does this sound correct??? I thought both should be drawing air out..?? Charlie
 

scoutabout

Lieutenant Commander
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Oct 14, 2006
Messages
1,568
Re: Bilge Blower Operation Direction

How many vents does your bilge have? That might help answer the question. If you have two only and they are both plumbed to the blowers, I'd say one should suck and one blow. Otherwise how does the fresh air get in?

If you have other vents with no hoses attached, I'd assume those would be the fresh air intakes and both your blowers should work to exhaust that air through their attached vents.

At this point I should note that I have experience with single blower setups only but common sense dictates the air's gotta get in before it can be blown out...
 

redone4x4

Lieutenant Commander
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Feb 28, 2009
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Re: Bilge Blower Operation Direction

that sounds correct. the fresh air comes in and the fumes go out at the same time.
 

RWilson2526

Master Chief Petty Officer
Joined
Jul 23, 2007
Messages
810
Re: Bilge Blower Operation Direction

I would agree with Scoutabout, if you have other means (vents) for the fresh air to get drawn in I would want them both exhausting....not sure of the configuration of your engine compartment and if you have an enclosed cabin area in proximity but if the blower that exhausted failed and the supply one kept running you would now be forcing the fumes into an enclosed space possibly.

As well I dont have any experience with this in a marine application but just using some rules that we use in construction and confined space situations....
 

arks

Lieutenant Commander
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Nov 7, 2002
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1,936
Re: Bilge Blower Operation Direction

Charlie-
Blowers can be used either way. Look at the orientation of your vent screens. I'll bet you'll see some facing forward and others facing aft. If facing forward it would be an intake.
THAT will determine which ones are intake or exhaust. You need to make sure the blowers are moving air in the proper direction.
 

crazy charlie

Vice Admiral
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May 22, 2003
Messages
5,581
Re: Bilge Blower Operation Direction

I have 2 vents across the stern and one on each side of the hull.I assume the ones on the side are for drawing air as I am underway and the stern is exhaust for the blowers.I will have to take a closer look.
 

Bronc Rider

Petty Officer 1st Class
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Sep 1, 2009
Messages
255
Re: Bilge Blower Operation Direction

I cant say I have ever seen one blower "sucking" and the other "blowing". Usually when I see two they are both "blowing" out.
As soon as the fans start blowing it will force fresh air into the bilge, no reason I can see to have a blower to pull air from outside.
 

rbh

Fleet Admiral
Joined
Mar 21, 2009
Messages
7,939
Re: Bilge Blower Operation Direction

ya know there is going to be a couple of jokes on this subject :D
rob
 

Bronc Rider

Petty Officer 1st Class
Joined
Sep 1, 2009
Messages
255
Re: Bilge Blower Operation Direction

^^^^^Yeah, I think I could have chose my words better. Oh well, we are all adults right?
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: Bilge Blower Operation Direction

To exhaust air from a sealed area, outside air needs to replace it. (Suck real hard on an empty soda bottle to prove this theory). To force air in, there needs to be a means of exhausting the existing air. (Blow on an empty soda bottle to prove this theory). Without that, the fans/blowers will cavitate which means they spin like crazy but move no air. If the boat has only two ports and both are fitted with blowers, AND (note the AND), there are other vents into which air can get into the bilge, then and ONLY then should both blowers be in the exhaust mode (sucking air from the bilge and exhausting it). Fresh air in that case would be drawn in to replace that being sucked out by the blowers. If there are no extra vents, then one blower needs to force air into the bilge and the other needs to exhaust it. It is very common to have one vent facing forward and one rearward so that movement of the boat creates airflow into the forward facing vent and air is exhausted through the rear facing vent.
 
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