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engine compartment cooling ?

CaptnNero

Accelerant
A very respected diesel mechanic in Annapolis recently suggested to me that leaving the blower on will significantly help reduce the engine room heat and improve alternator performance too. I was skeptical until I tried it recently. Since the blower has a momentary switch I only ran it about 20 seconds but I was surprised how warm the exiting air was which suggests that the blower will actually move a lot of heat out of the boat.

Now of course to do this I would need to replace the momentary switch with a full throw one that stays on. I am concerned about constantly running the blower for the hour or two that the engine runs.

Does anyone know if the factory blower can handle being left on whenever the engine runs ?
 

ted_reshetiloff

Contributing Partner
I am not sure if I have the factory blower or not but I run mine all the time for the very reasons you suggest. I redid the insulation in the engine compartment and made it more air tight, well sort of anyway, and I have the blower sucking from the top strbd corner and the inlet from bottom in the hopes of moving as much air as possible. I plan to upgrade the blower at some point to a bigger unit. The engine and its cooling hoses give off a lot of heat. My fridge compressor in the cockpit locker often ends up sucking hot air because the exhaust hose, coolant expansion tank, and hot water heater are in there all radiating heat. I try to let the engine run for a while after we anchor to get it cooled down as much as I can but on a hot day after motoring for several hours it can leave the cockpit locker a bit warm. The insulation really helped keep the heat out of the aft cabin, but some still comes through from the cockpit locker side. I am planning on trying to insulate those hoses too but its a bit more work. I can use the foam pipe insulation on the hot water heater hoses but I am not sure what I will wrap the 1 3/4 ID exhaust hose with.
 

Ray Rhode

Member III
Neal,

Most of the axial flow blowers are not designed for continuous operation and can actually catch fire when overheated. Like Ted I also like to run the blower anytime the engine is running and for 20-30 minutes after shutdown. I replaced the P. O. installed Attwood blower with a Jabsco "squirrel cage" model that is rated for continuous operation. It also turned out to be quieter.

Ray Rhode
S/V Journey
E35-iii, #189
 

CaptnNero

Accelerant
Thanks guys, next time I'm there I'll lean into the lazarette to spy the blower type. I already know the water heater hoses aren't insulated so I guess I'll pick up some soon.
 

Shadowfax

Member III
On my 34 the switch is a regular toggel. I usually run the fan when the engine is running especially in hot weather. I have run it for hours on end with no problem and it does throw out a lot of heat. Get a new switch
 

Glyn Judson

Moderator
Moderator
Bilge fan life expectancy.

All, Some years ago I too was dealing with engine room temp issues relating to my Adler Barbour comperssor located 18 inches away from the engine, getting too hot. Before running my ITT? bilge fan when ever under power to help reduce the heat in there, I contacted the maker and spoke with one of their tech reps. He looked it up and noted that it was rated as a "Continuous Operation" motor. He said that I should expect at a minimum, 1,000 hours of nonstop operation if not lifetime operation. He told me that if it ever failed, they would replace if for free. Regards, Glyn
 

LJS

Far Reach 29
a previous owner had replaced the atomic 4 on our 29' with a Yanmar 18 hp - we had to build a soundproof cover to bring this under control but were concerned about heat buildup - for a couple years we ran the 3" axial fan all the time the engine was running and had no problem except for an annoying noise from the fan itself - last year I replaced this with two 12 volt computer exhaust fans mounted in a box over the batteries, connected with 4" flexible hoses - the engine air seems to cool sufficiently by the time it reaches them - these are not from PCs - they are surplus from mainframe computers and are designed for continuous operation - and they are quiet! Larry
 

cawinter

Member III
Run time not an issue

Same as Paul, I leave the blower on while the engine is running. We just did a night-time run through New York Harbor out to the Sound. 6 hours and no problem.

I liked what Lauren did, and in the end state (???) I'd like to replace the vinyl hose w/ aluminum and route it from the top of the engine compartment to extract even more heat. Since this involves opening up the "wall" I'll wait until there are a few more reasons to do that. BTW, two years ago I replaced the NICRO vents with very lovely Mariner's Hardware SS. Sweet.
 

CaptnNero

Accelerant
The Wall

I think I know that "wall" you are talking about in the starboard locker. I also need to open that wall to fix the fuel fill and vent hose routing which is still going downhill from the tank. Maybe I'll do the metal ducting you suggest while I'm at it.

thanks everybody for the ideas on engine cooling.

cawinter said:
Same as Paul, I leave the blower on while the engine is running. We just did a night-time run through New York Harbor out to the Sound. 6 hours and no problem.

I liked what Lauren did, and in the end state (???) I'd like to replace the vinyl hose w/ aluminum and route it from the top of the engine compartment to extract even more heat. Since this involves opening up the "wall" I'll wait until there are a few more reasons to do that. BTW, two years ago I replaced the NICRO vents with very lovely Mariner's Hardware SS. Sweet.
 

Loren Beach

O34 - Portland, OR
Senior Moderator
Blogs Author
vents and blowers

I hope you guys are not talking about me... :rolleyes:

I used the standard 3" vinyl spiral-wire vent ducting to replace the original (same stuff, just old and cracking apart).

I did lead the intake to the top of the engine compartment, and near the alternator.

I do run the blower all the time the engine is running, and it removes a constant bunch 'o' hot air.

Loren in PDX
Olson 34
 

Chris Miller

Sustaining Member
in or out?

I checked my blower last night while pulling the AC pump (on the hottest day of the year, just like last time:headb: ) after reading this thread and it is setup as an intake... seems like I'd want it pulling out, but then it occurs to me that having it supplying my engine with nice cool air would be good.
I didn't install it, but obviously turning it around wouldn't be serious either.
Chris
 

cawinter

Member III
Typos abound

LOREN, sorry. I hope I don't get 'moderated' off the list now... :)

The only problem with the 'wall' on my E34 (#267) is that I can't get to it without moving the holding tank aside. There are a few screws on the bottom that are covered by the tank. Incidentally, the tank with its hoses also prevents me from replacing my broken water heater. Had that discussion with Tom a while back. His setup was different, and he was able to remove it without tank issues. Given the magnitude of what I could conceivably open up project-wise...I might just wait unti retirement ! Tom is always nice enough to point out that I'm about 100 years away from that;) Oh well...

Now for the content: Blow out is better. There is plenty of cool inflow through the aft openings into the engine room. In fact, one could argue that much of that air is cooled by the ambient water temperature. I wanted to go to Al simply to avoid crushing in the future.
 

CaptnNero

Accelerant
Push vs Pull

For safety's sake I'd rather be pulling air out than pressurizing the engine compartment which would more easily deliver any fumes or even fire throughout the leaks around the engine compartment.

Chris Miller said:
I checked my blower last night while pulling the AC pump (on the hottest day of the year, just like last time:headb: ) after reading this thread and it is setup as an intake... seems like I'd want it pulling out, but then it occurs to me that having it supplying my engine with nice cool air would be good.
I didn't install it, but obviously turning it around wouldn't be serious either.
Chris
 

Captron

Member III
Blowers

I doubt if an air intake is needed at all since most engine compartments are not well sealed. I too, ran my blowers (both sucking hot air out of the engine compartment) continuously but they're both in failure mode ... need to check out the Jabsco unit mentioned as rated for continuous use ... quite expensive as I recall.

Maybe it's because I'm trying to make my blower ... errrr ... suck?:p
 

Shadowfax

Member III
The Wall

Chris,

I'm amazed that there is that much of a difference between your boat's layout at hull #267 and mine at #257. Tom is #234, I think, and his layout is the same as mine. For me taking the wall apart is very simple and I've done it a half dozen time with running various wires. I think trying to rerun the duct in rigid aluminum would be a chore and suggest you look at the flexible aluminum duct that expands to 8 foot sections. We use it for dryer & hood vents all the time now and it should be available at any good lumber yard, or hardware store. Be aware there are 2 grades. You want the heavier one.


QUOTE=cawinter]

The only problem with the 'wall' on my E34 (#267) is that I can't get to it without moving the holding tank aside. There are a few screws on the bottom that are covered by the tank. Incidentally, the tank with its hoses also prevents me from replacing my broken water heater. Had that discussion with Tom a while back. His setup was different, and he was able to remove it without tank issues. [/QUOTE]
 

CaptnNero

Accelerant
amobient fan temp

I suppose the longevity of the cooling fan will be affected by the temperature of the air it moves. If we use the fan in pulling mode, it's going to be considerably warmer with the exhaust air running over it.
 

CaptnNero

Accelerant
Wall version ?

Since KOKOMO is #253 I'm hoping it will be an easy wall removal like Paul's.

At this point I have three projects behind the wall and I think I'm going after it soon.
 
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Glyn Judson

Moderator
Moderator
Buying an affordable blower.

Captron,

Try a consignment store near you for a more affordable blower. I know Minny's always has a bushel basketful of them at a very fair price. Don't know where to find on near you? Go to http://www.goodoldboat.com and click on the Consignments Store in the column on the left of the home page. You'll find a ton of them there.

Good luck,

Glyn
 

Tom Metzger

Sustaining Partner
I have never removed "the wall" on my E-34 #234. I cut an access panel into it to replace the fuel fill hose a year or so ago. I would have to remove the holding tank to remove the wall. I did replace the hot water tank without removing the holding tank (only the fill hose).

As a matter of course, I do not run the blower when running the engine, but then my engine is water cooled and temperature regulated. :egrin: In hot weather I will remove the engine cover after powering to speed cooling for more comfortable sleeping at night. My alternator is over rated so I don't worry about it overheating.

Nowhere in the owner's manual does it recommend running the blower.
 

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CaptnNero

Accelerant
Owner's manual version ?

While the original idea of running the blower was suggested to me by a diesel mechanic for the sake of the alternator performance, it got me thinking about dumping heat from the boat. The area around the engine gets rather heat soaked, probably mostly from direct radiation. When I did a test with the blower for a while on underway I was surprised at how warm the exhaust air actually was. Yesterday it was 102 degrees F in the shade here and pumping heat from the boat sure sounds like a good idea.

The idea of removing the engine cover on anchor wouldn't work well for us. Space is at a premium and the cover definitely would have to be put out of the way somewhere far away from the central area. These boats just don't have far away places.

With the upgraded battery capacity that KOKOMO now has, I may even run the blower for a while after shutdown, livin' large.

I read the owner's manual too, but I noticed that it hasn't been updated for a very long time...;)

Tom Metzger said:
...As a matter of course, I do not run the blower when running the engine, but then my engine is water cooled and temperature regulated. :egrin: In hot weather I will remove the engine cover after powering to speed cooling for more comfortable sleeping at night. My alternator is over rated so I don't worry about it overheating.

Nowhere in the owner's manual does it recommend running the blower.
 
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