bilge blower

[jann]

My Mainship Bilge blower failed...I never used it....can anyone tell me why Mainship put a bilge blower in a diesel boat.

 

[Xsbank]

Engine room/ambient air cooling?

 

[Comodave]

Where is it mounted? Up high it is to suck out heat after a run and also diesel smells when the engine room is hot.

 

[caltexflanc]

And if down low, to evacuate battery gasses.

 

[RT Firefly]

Greetings,
Mr./Ms. j. Mainship also made gas models. Perhaps they put blowers in all their builds.

 

[GregBrannon]

My diesel boat has them with the placards near the switches that 'require' them to be turned on while refueling and some number of minutes before starting, just like my gas boat. Was it a requirement when the boats were built, possibly regardless the engine type? The operator's manual advises running them after engine shutdown to cool the engine room.


In fact, I just remembered, that one of them wouldn't run was a ding on my purchase survey that the insurance company insisted be fixed before the delivery trip. Go figure.

 

[porman]

Our manual also says to run it after shutdown to cool the engine compartment. No mention of running it during fueling.

 

[Lepke]

On diesel powered big boats and ships there are usually large powered blowers for both intake and exhaust air. By keeping the engine room cooler, the engines get a cooler, condensed air with more oxygen leading to better economy and power. Another advantage is the compartments near the engine room are cooler.

 

[jimL]

When we bought the boat 4 yrs ago, the output duct had collapsed and there was no way I was going to climb back there to replace. I used a semi-flexible dryer vent accordion hose and used that to move the exhaust air to the port vents. After three years, I don't know if it makes a difference, but my ER gets to be over 100F in the summer and I figure the sooner I can get the twin Yanmars cooled, the better the AC will work. I have tried cruising with the blower on and it doesn't seem to make a difference with the ER temps. I'm thinking of mounting an oscillating fan from the ceiling and using that to circulate the air. Thinking that - I also realize that twin Yanmar 370 turbos are consuming tremendous amounts of air per minute and that alone should figure into the air requirements for combustion and cooling. Do you think Mainship engineered the air input/exit grates accordingly considering all of the above?

Jim

 

[psneeld]

Funny that Mainship said run them when refueling...that goes against NASBLA boating safety course training.


Due to them pulling vapors into the bilge. Run them AFTER refueling if anything.

 

[Symphony]

I have had my 34 pilot for only one season. The blower is high exhaust. I tried it times, and I can put my hand out the helm window to feel the temperature of the air exhaust. I never felt much difference whether I ran fan or not. I figure the best use of it is to try to cool the engine room once you have stopped, but the fan is pretty noisy and doesn’t work as fast as opening up the engine room and letting the heat out.

 

[boatpoker]

Funny that Mainship said run them when refueling...that goes against NASBLA boating safety course training.


Due to them pulling vapors into the bilge. Run them AFTER refueling if anything.

Blowers on a gas boat blow air (and vapours) out not in.
Whle blowing air out, passive intakes on the other side of the engine compartment draw fresh air in due to the vacuum created by the blower.

 

[OldDan1943]

When my 2008 AT was constructed, exhaust fans in the ER were not required.
I have told the USCG this and of course, they realize they are unnecessary.

I do have a fan that draws from the ER, to share the heat with the rest of the boat in the winter.

 

[RT Firefly]

Greetings,
Mr. bp. "Blowers on a gas boat blow air (and vapours) out not in." Of course they do but I think Mr. ps's point is that whilst running, during refueling, they also CAN draw vapours in through the passive vents.
I would NEVER even consider running the blower on our gas boat during refueling. I refer you to page #38 of the Transport Canada Safe boating guide where it is recommended that during refueling, among other steps, the boat should be closed up (hatches, ports etc.). I suspect US recommendations are the same.

Running a blower during refueling could easily draw explosive vapours into the engine compartment due to wind conditions and the fact that the "passive" air intakes (which CANNOT be closed up) might not necessarily be "...on the other side of the engine compartment..."

 

[OldDan1943]

Greetings,
Mr. bp. "Blowers on a gas boat blow air (and vapours) out not in." Of course they do but I think Mr. ps's point is that whilst running, during refueling, they also CAN draw vapours in through the passive vents.
I would NEVER even consider running the blower on our gas boat during refueling. I refer you to page #38 of the Transport Canada Safe boating guide where it is recommended that during refueling, among other steps, the boat should be closed up (hatches, ports etc.). I suspect US recommendations are the same.

Running a blower during refueling could easily draw explosive vapours into the engine compartment due to wind conditions and the fact that the "passive" air intakes (which CANNOT be closed up) might not necessarily be "...on the other side of the engine compartment..."

With gasoline, as I recall, you want a dead boat. Everything electrical shut off. After feelings complete, run the fans for 15 (?) minutes and then, crawl down and sniff the bilges just to make sure there are no fumes.

Diesel boats, after refueling, sniff the bilges..... no biggie

 

[RT Firefly]

Greetings,
Mr. OD. "...a dead boat." EXACTLY!!! I have had 2 occasions, in the last 30+ years, after re-fueling gas boats, where I needed to address the source of gas fumes. Readily dealt with and no-one was allowed onboard or even near while I rectified the situations.



I've been told and I agree with it that the "nose" is FAR superior to anything else in detecting gas fumes.

 

[sunchaser]

Our vessel has two ER blowers, one out and one in. Being a DeFever, the ER is good size allowing decent access for maintenance and checks right after a day's run. During these chores the blowers keep the ER crew comfortable. During cruising the blowers are off with the ER temperatures tolerable due to adequate passive ventilation, wet exhaust and smallish engines.

If we boated in warmer climes than the PNW, more blower capacity would likely be required.

 

[Ski in NC]

On a hot summer day after running the main and then putting on the gennie, my ER gets HOT. Gennie end is air cooled and probably not too good for it to bake. So I run the exhaust blower then.

When main is running, it draws enough air to keep ER reasonably cool. No blower on then.

My exhaust blower draws air from top of ER near gennie and discharges through a nozzle in one of the ER vent plenums. This entrains air flow in the plenum and multiplies the air flow. Discharge on port plenum, supply on stbd.

 

[psneeld]

Thank you RTF..exctly the reasoning behind NASBLAs training suggestion....


Now whether there are credible arguments the other way.... I certainly could see some.

 

[boatpoker]

Thank you RTF..exctly the reasoning behind NASBLAs training suggestion....


Now whether there are credible arguments the other way.... I certainly could see some.

On a gasoline powered vessel, blower motors are required to be ignition protected. If the ventialtion system is set up as per ABYC (I know many don't like ABYC) the chance of drawing fumes back into the vessel are infinitismal.

That being said there are many mfg's that while they say they build to ABYC, clearly do not. Gasoline Ventilation on Boats.

In Canada a gasoline boat is required by law to run the blowers for 4 minutes prior to ignition.

I have no opinion just stating the ABYC and Transport Canada requirements

 

[OldDan1943]

Let's face it, if you have a gasoline powered boat, you know you need a bilge blower, common sense. Boatpoker indicated Canada says 4 minutes. I thought the recommendation for gas boats in the US was closer to 15 minutes. Regardless of the minimum time, do it but only if you like your boat and those who travel with you. WINK

 

[vanderzeeh]

There is also another reason to keep the engine room cool, the batteries.
Batteries will live longer if the environment where they are located will not become too hot. If your batteries are not mounted in the engine room then this reply does not concern you.


Harrie...