I guess I m either trying to re invent the wheel or to think out of the box ...
Using a little DC blower to extract heat from the ER doesn't really do anything... blowing air directly from outside isn't a great idea as it just brings a ton of corrosion which I don't want to do on new reman engines and new air cons
So, I m thinking of using 120v squirrel blowers pulling air from the genny room into each ER. Even if in the 250/300 cfm range there is plenty of opening thru the ER vents so that the ERs don't get pressurized and leak ER air into the staterooms.
The air flow thru the genny room would also help cool it. What am I missing ?
Many larger boats use AC blowers to pump air into the ER, I like the idea
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Engine rooms ventilation and cool down
Pascal
Miami, FL
1970 53 MY #325 Cummins 6CTAs
2014 26' gaff rigged sloop
2007 Sandbarhopper 13
12' Westphal Cat boat
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Re: Engine rooms ventilation and cool down
I use a squirrel cage to blow into ER from the cockpit after running. 137 degrees trumps corrosion (for me). It works because the blower is made by Dayton and not March.
Semper Siesta
Robert Clarkson
ASLAN, 1983 55C #343
Charleston, SC
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06-22-2017 06:37 AM #3
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Re: Engine rooms ventilation and cool down
Our 53 has a 120vac dual impeller squirrel cage blower at the ceiling of each engine room that exhausts air out via the engine intake vent. There is a sheet aluminum "duct" approximately a foot wide/a couple of inches deep from the blower exhaust outlet sealed to the top side of the vent, where the vent's Dorade box screen is mounted.
Seems to work pretty well.
BUT...don't expect too much; 3500 lbs of hot metal (DD 8v71TI+transmission) makes a really good heater!
To be honest, I don't use the blower very often unless I'm planning to be IN the engine room shortly after shutdown. Other than some attempt at creature comfort if you are going to be in there, there is no functional need for a blower. I guess it might help keep the boat a bit cooler after a run but I have never really noticed any engine heat warming the salon floor in our 53.Mike P
San Miguel de Allende, Mexico; Kent Island MD; San Antonio TX
1980 53MY "Brigadoon"
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Re: Engine rooms ventilation and cool down
Less stuff to corrode in the genny room... the genny is better protected in the sound shield and it gets hot in there with the genny running for days
Mike, I m sure hatteras improved the insulation in 10 years, and I will do that too but there is no doubt that my boat was hotter after a run. Even after shedding about 1400lbs of metal per side, keeping the ERs cooler has many benefits. Forced ventilation makes it more pleasant to work in there even when the engine are cold. Here in south Florida most of the year it's hot in there with no ventilationPascal
Miami, FL
1970 53 MY #325 Cummins 6CTAs
2014 26' gaff rigged sloop
2007 Sandbarhopper 13
12' Westphal Cat boat
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Re: Engine rooms ventilation and cool down
I added an AC squirrel cage blower in the engine room of our 41 DCMY many years ago. I added a second 3" exhaust duct in one of the engine room air inlets. It not only helped cool the engine room faster after a run (probably a marginal benefit), but more importantly keeps the engine room at a slightly lower pressure than the saloon when only the gen-set is running. The air swallowed by the Detroits prevents any fumes from the engine room entering the saloon when they are running, but with only the generator running heat and fumes (hot oil smell-not exhaust leak) entered the saloon.
I suggest you place your new blower in the engine room with its discharge exiting the air intake. If you have the blower discharging into the engine room it will slightly increase the pressure. If there are any leak paths (even very small ones) hot air will flow from he engine room into the passenger spaces.
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Re: Engine rooms ventilation and cool down
On our 60C the engine air intakes are in the cockpit under the bolsters. The engines run at 173 degrees, so after a run if the ER is kept closed the temp is......173-ish. While running it's fine of course, twin 12V71's and a 20kw draw a lot of air.
I have large (10" x 10" outlet) 110v squirrel cage fans in the air intakes to force air through, after a run I open the cockpit hatch and run the fans for a couple hours, this cools down the ER surprisingly quickly. At least it makes it livable to go down there right after running. Without the fans running it's a sauna.Last edited by luckydave215; 06-22-2017 at 10:52 AM.
"The older I get, the faster I was......."
1979 60C "Ohana" hull# 331
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Re: Engine rooms ventilation and cool down
My surveyor recommended that I take the long plastic blower hose off. He said you're trying to get rid of heat. There are no gas fumes in there. Your thoughts?
SEVEN
1979 53' MY Hull #563
Antioch, California
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Re: Engine rooms ventilation and cool down
Rusty, he is correct, hot air rises so why would you have a hose on the blower that goes to the floor of the engine room if you are trying to remove heat with the blower. That hose is correct for gas engines where you are trying to blow out any fumes in the bilge before starting, but for diesels not so. John
Mahalo V
1974 53 Motoryacht
Hull Number 406
San Diego, Ca. Ready 32 Nordic Tug, Brunswick Ga.
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06-22-2017 11:50 AM #10