Do I need an Engine Room Blower?

[aquavit]

In my 1990 diesel powered E28, there is a functional engine room blower fan and duct hosing. The installation is obviously original. However, the ducts are not vented to the outside of the boat, they are connected to thru-hull fittings at the top rear of the cockpit coaming sides that have blank plates covering them. The system is therefore completely useless. Since my engine is a diesel (explosion-proof as far as I know), the boat has not exploded at any time during the past 20 years, the ducting and blower are using up valuable engine room space and reducing access to the steering quadrant, what compelling reasons are there for me not to take it out? If I take it out, I promise to keep the original parts so that any future owner can go through the same mental exercise.

Glenn (Aquavit), at the start of a busy pre-season update program.

 

[Glyn Judson]

Bilge fan for a diesel?

Glenn, I too had a bilge fan fitted with vent hoses seemingly everywhere in Yanmar diesel powered engine room and wondered what the company could have been thinking of. I soon got rid of all the hoses and relocated the fan to the underside of my mushroom vent located on the port, quarter side deck. Having read enough about how diesel engines like a cool environment, I now use the fan on hot summer days when it's necessary to run the engine for hours at at time. Please feel free to email me back channel for a few photos of my installation. Survivor of the great 2011 Tsunami (1.2 feet), Glyn Judson, E31 hull #55, Marina del Rey, CA glynjudson@roadrunner.com

 

[Loren Beach]

Heat, Fumes, and Exhaust, oh my...

Blowers, engine compartment heat, and duct questions have come up before. A search on blowers will bring up quite a few threads. Here's one:
http://www.ericsonyachts.org/infoexchange/showthread.php?t=3602&referrerid=28

Given that your boat has a diesel, I would first make sure that the blower fan is working (and after all these years a new one might be a good idea). Next, check out the condition of both runs of hose -- it's not expensive and if it's brittle and cracking, just replace it. Both the supply and exhaust.
And, make sure that the ventilator is open to the outside.
Further, if the suction end of the hose (intake) is at the bottom of the engine compartment, move it up near the top where the heat is, and reasonably close to the alternator. Run the blower any time the diesel engine is operating. Exhausting that hot air from around the block is a small (est. 5%) part of transferring waste heat from your engine, but still calculated in by the engineers. Engines and alternators do not like too much ambient heat.
For a gasoline engine, do keep it low down, to exhaust potential explosive vapors.

Cheers,
Loren

 

[rwthomas1]

I don't think that a blower is necessary on a diesel boat. The blower on my boat has been inop since I got her. The blower was dead, shaft frozen and the hose had been removed by some PO. I removed the blower and tossed it as it was in the way of some access I needed at the time. I have considered replacing it as I think the idea of ventilating the engine space during extended motoring. I do know the alternator runs extremely hot when charging.

My problem is evey exhaust blower I have seen is rated for intermitant use or actually lists its lifespan in hours, usually not that many.... If I go to the trouble of reinstalling a blower I want the thing to last!

The ideal installation would be pulling hot air from the top of the engine compartment, near the alternator and pushing it out a dorade vent at the stern.

Its just not far up the to do list....

RT

 

[Bolo]

Warm air

I too have an blower system on my E-32 III and at first wondered why it was installed in the first place for diesel engine use. But as I did learn later it does helps with keeping things cool in the engine compartment and when underway using the diesel for a long period of time I can definitely feel warm air coming from the exhaust cowl mounted at the top of the transom. Keep it cool!

 

[Dan Morehouse]

My blower works, but I was about to ditch it until I read these posts. Now I guess I'll have to replace the nasty flex duct I tore out, only run it to a spot near the front top of the engine. If I really wanted to improve things, maybe I could install a flatter rectangular duct along the underside of the cockpit sole for that and save room at the same time. The flex dryer type duct just looks wrong on a boat.

Dan Morehouse
1981 E-38 "Next Exit"

 

[Christian Williams]

This is a perennial topic with no clear conclusion, so let me add a recent excvhange between me and a well-regarded marine surveyor. Take it for any value it brings.

Question:

"I want to remove the entire blower and vent hoses system from the Ericson 38. It’s a joke. The vent hose suction end, 3-4” accordion tubing, starts off lashed over the engine block, then bends and sags 5 feet to the blower, then bends and sags 7 feet back to the cowl vent. It is removing very little hot air. To vent the compartment, just open the 4’ seat hatch. Also, the two big cowl vents at the stern let more hot air escape with no hoses connected to them at all.

"And as I understand it, a blower isn’t required for a diesel.

"My question is: what do you say on your survey report when a boat like the E38 has no blower for the engine compartment?"

Reply:

"All good points! Since a blower is not required on a diesel powered vessel, if I were to find a boat with no blower (which is common), I would make no recommendation."

 

[Cory B]

Hand Warmer

A small bonus of a blower is if the output is near the helm, it can make a nice handwarmer on cold days.

We replaced the rusted piece of junk that came with our current boat with a cheap-ish $30 plastic blower. I usually run it whenever the engine is running (old habit from having gasoline Atomic4 in previous boat). The blower is still going strong. I also thinks it helps keep any "engine smell" out of the cabin.

As everyone has pointed out, you don't have to worry about diesel exploding. However, we do have propane on board. While its unlikely we would ever have an undetected leak, especially with a sniffer, the blower is a little bit of extra insurance.