Engine room fan

[NZL50505]

The Jabsco blower (extractor fan) in my 42DS engine room blew last week so I replaced it with identical looking Eastern unit. After 3 hrs use the fan blade flew off. I tried to epoxy it back on but it flew off again after another 3 hrs.

In my mind it’s a nice-to-have but not essential component - we are at the start of a month cruising so I’ll replace it when I next get the chance in the next week or so but don’t plan to change our holiday plans to get it fixed urgently eg delay departure and getva unit couriered to our present location.

Am I right?

[vasko]

Feb 6, 2018 5:01:58 GMT NZL50505 said:

The Jabsco blower (extractor fan) in my 42DS engine room blew last week so I replaced it with identical looking Eastern unit. After 3 hrs use the fan blade flew off. I tried to epoxy it back on but it flew off again after another 3 hrs.

In my mind it’s a nice-to-have but not essential component - we are at the start of a month cruising so I’ll replace it when I next get the chance in the next week or so but don’t plan to change our holiday plans to get it fixed urgently eg delay departure and getva unit couriered to our present location.

Am I right?

There are different views I do not think it is life saving, but it is essential as the boat can become smelly and the engine bay mire hot then it needs to be..

[ForGrinsToo]

I agree with Vasko. When ours failed, I appreciated the quiet. In fact, I noticed the hot engine odors in the cabin well before I noticed the quiet and was a bit slow to figure it out. There is a very good reason why many have chosen to install a thermostat - on my to-do list for next season. But having the blower is not critical. As long as you have good ventilation of the cabin, and the Admiral is happy, you can probably get by.

Geoff

[NZL50505]

Thanks got it.

[MartyB]

If you had a gas motor vs diesel, the exhaust fan would be very important.
As noted from a diesel standpoint, not needed. I can see on a warm summer day you could keep cabin cooler. In winter, that heat is kinda nice!
For what it's worth, my boat has never had an exhaust fan for the engine compartment.

Marty

[ForGrinsToo]

I am about to replace the SO36i engine room fan for the second time. The original is a Rule 4" 12V version (Rule 240). Since two have failed, I am wondering if anyone can recommend an alternative, such as the Shurflo 277-4110 or something else?

Thanks,
Geoff

[NZL50505]

I’m still annoyed by the noise of ours. Are there quieter options (not a bit quieter but much)?

[sitara]

The Rule engine room fan on my SO36i got very noisy so I replaced it with another, same make. The new fan is heaps quieter and the cost of changeover is minimal. I did install a thermostatic switch for the fan so it only comes on when the engine room warms up. It now only comes on after the engine has been running for some time. See Hints and tips www.jeanneau-owners.com/hintsandtips/variablefan.html.

[alenka]

Ambient temperature has a big say in when our fan cuts in and how long it stays on for.  On chilly days this can take quite a while to activate.  
Where is your cruising sound?  The tropics of somewhere a little cooler??
I gather some fans are wired to the ignition and come on with that rather than a thermostat. Is yours on a thermostat?

[ForGrinsToo]

Thanks for the comments. I have purchased another Rule 240 hoping that it will last longer because I am also installing a thermostat as Sitara suggests, so it should run far less than engine hours. Nobody has recommended Shurflo, Attwood, West Marine, Johnson, or anything else as a quieter or more reliable blower.

Geoff

[NZL50505]

My noisy fan is wired to ignition. Rather than install thermostat and reduce time it’s running I’d rather have a much quieter full-time fan (I think it has a full-time role removing engine smells regardless of temp). When it stopped working I immediately noticed unpleasant engine smells down below.

[alenka]

Our fan is  down in the engine compartment so I doubt it will be heard above the din of the Yanmar.  I suspect the noise, which is considerable, comes more from a large volume of air been crammed through a relatively small pipe.

Agree it probably freshens up the area and even if contributes nothing to cooling the engine helps to keep the panels cooler which get pretty warm and warm the boat. Something we don't want here in the Med in summer. 

[alex1949]

Hi folks, I am from Israel so speak with me about hot weather......
My engine room fans are attached via manual on/off switch on the engine board. No thermostat is used to activate it.
I hardly or may I say I never use it. My Volvo engine cools itself quite efficiently and during cool weather time I 
think it feels better taking in a bit warmer air to deal with. Same on my present 2005 D2 55 with 1500  hours on it same was 
my previous Yanmar 1998 30 hp on my SunShine 38'.
I do think that this arrangement was born for gas/petrol engines, no need for diesel engines. Nice to have,to clean air at 
engine compartment if desired - yes but not automatic constant use.
One should keep his motor heat exchanger (especially when we talk Volvo) clean and treated once in 5 years rather
then use these fans cooling our motor down .

 

[captbillh]

I have a 2015 409. After 330 eng hours the ventilating fan became rather noisy. I stated up the engine to pull into mooring field. The bow thruster would not "activate". The next morning when starting the engine the charging light and alarm came on and stayed lite. The alternator was not charging. It tested ok. The 7.5 Amp fuse blew that feeds the blower motor and the 2 permissive relays for the bow thruster and the windlass. The circuit did not have a low resistance but the fuse blew again.
The blower motor installed by the factory was a Jabsco 6.5 Amp that requires a 10 Amp fuse. When I replaced the fuse with a 10 Amp everything worked. The schematics in the manual details most of the wiring but not the interface between the Yanmar panel and engine/alternator wiring to really explain the reaction to the blown fuse. The feed wires for the key relay located on the port side of the engine is not shown on the schematics.
The replacement fan is a Plastimo 5 Amp model. The Jabsco 6.5 Amp fan was used on a 409 built in March 2014 also.
The Jeanneau 2019 51 and the Beneteau 2019 51.1 model have the Plastimo 5 Amp fans installed.
The Jabsco had originaly a lower noise level than the engine. The Plastimo fan is now lower than the engine. 

[alex1949]

Too much troubles with those fans. You really do not need them !!!
Try to work without, see if your engine have any objection, mine a very delicate Volvo Penta have no reservations.  

[NZL50505]

Aug 27, 2019 19:15:10 GMT alex1949 said:

Too much troubles with those fans. You really do not need them !!!
Try to work without, see if your engine have any objection, mine a very delicate Volvo Penta have no reservations.  

You’re missing the point.

The engine won’t have any objection.

It’s the crew who don’t like the smells of a hot engine room.

[alex1949]

Dear NZL8970,
Mutual agreement that those fans are not essential for the healthy operation of the diesel engines, this is what boaters should know.
How and if one use them nevertheless, is up to anyone decision knowing that avoiding the fans will not harm the engine.
I myself made my selection long time ago and my case can prove that it is safe to do.

[aussieodyssey]

On our 45.2 with a 75hp Yanmah we have fitted a 12volt computer fan just for getting out of the marina to go for a sail . Always runs and the big blower is on a manual switch. 


www.23hq.com/liquidity/photo/60625032/original

[braders]

I have a attwood - Turbo 4000 extractor fan on my 44i, works well 

[so36idavid]

Marine diesels like clean, cool air. They won't explode if they don't get it but they won't run as efficiently and will wear faster. Here's an article which explains why. Even if you don't believe this theory, stick your nose into an unventilated engine compartment sometime. They're really hot and smelly which will result in a hot, smelly boat. The hard part in ventilating them is usually fitting the ducts. Most modern Jeanneaus have engine room ducting. Putting an appropriate fan inline is pretty cheap insurance. 

David

[sailbleu]

I find it a bit strange that people object to a working engine room ventilator .
In my cockpit I have a display where I can read/check the engine temp. raw water outlet and also the engine room temp .
When you have that kind of reading of the engine room temp you understand the necessity of a fan . It really becomes hot in there .
That will put an extra strain on the engine parts and in the long run cause more wear and break down .
I even installed a fan in the air supply hose so I have , as an additional benefit , a spare for when the evacuation fan gives up , every 3 years or so .
These days I replace the evac. fan whenever I hear some disturbing sounds coming from the small dried-out and rusty bearings, usually an indication for an imminent shut down .
The price of these fan is not really an obstacle anymore.
www.aliexpress.com/item/33021014928.html?spm=a2g0s.9042311.0.0.27424c4dyGJLz3

Whenever I see my engine room temp rise above 40°C I switch on the supply fan and a relay also switches the evac fan on at the same time to avoid smell escaping the engine room .
Within half an hour the temp drops to outside atmospheric temp. and the engine itself goes down a few °C .
When we have an anchorage after some motoring I leave both fans on for awhile so the engine does not transmit that much heat to the cabin and aft bedroom . In the Med. & tropics every degree down counts for a good night sleep .

Regards

[Bijoux]

Oct 2, 2019 20:01:14 GMT braders said:

I have a attwood - Turbo 4000 extractor fan on my 44i, works well 

Braders,

Is the Attwood quiet?    I have the stock fan and it's extremely noisy..  
It's worse then the generator itself.

[shantiskipper]

I would also like to add that keeping the alternator cool is important. Especially if you have high output!

Daniel 

[braders]

Hi Bijoux

The Attwood fan is quiet - would recommend it 👍

[NZL50505]

Oct 13, 2019 18:37:54 GMT braders said:

Hi Bijoux

The Attwood fan is quiet - would recommend it 👍

Ok that’s what I need then.

Is it a normal looking fan (blower) design or something different?