Can I remove the blower and hoses?

[Christian Williams]

Lithium batteries on fire?

Joke vs. joke

(refers to forum discussions of clean cool quiet electric vs. overheating dirty stinking diesel propulsion)

 

[David Grimm]

The early model of the 38-200 has it's own set of ventilation challenges. The engine compartment under the gally sink is isolated from any passive ventilation. The 3 inch dryer vent hose has an extremely long run. It zig zags under the stove and aft quarter birth, then past the engin controls in the starboard lazerett, to the blower unit itself, then out the starbord stern cowl vent.

The blower is manually switched at the engine control panel and if left on for 5 min or so you can start to feel some warm air exit the vent.

The blower is basically useless. I have thought of relocating the blower and directing the exhaust to the aft quarter birth deck cowl vent location. This would free up the stern cowl for passive ventilation, however I do not have a cowl for the deck and would worry about water intrusion on a starboard tack.

All that said, while typical motoring I don't ventilate the engine compartment however when out at sea and fast charging the lithiums for an hour or so I just open the top of the counter and sometimes remove the under sink side cover to let the alternator breathe. I also have to open the hanging locker to let the 60 amp Renogy dc-dc charger breathe. If I don't the dc charger will shut off on the hot 90 degree days.

This whole ventilation situation is frustrating. It's annoying to me on a passage and I'm alone. I couldn't imagine subjecting passengers to 1,200 rpm's of engine in a 90 degree± cabin for an hour and a half every 12 hrs. Or so.

Also, Ericson provided no intake vent for the ventilation system, and the engine compartment shares a wall with the ice box!

One saving grace, in the lower latitudes the 400 watts of solar reduce engine run time to 1 hr every 24hrs on sunny days.

 

[Christian Williams]

David, in the -200 interior redesign, the engine seems sealed. Is there really only one vent with blower?

I know it's very different from the 381, in which the engine bay is open to the vast space below the cockpit, and passive ventilation is easy.

Any way to blow air in there, with another way for it to get out?

...
E381 engine bay, 38-200 engine bay

 

[David Grimm]

As far as I can see, there are two ways of getting the heat out.

One is to put a baffeled intake with fan somewhere on the kitchen peninsula, and the exhaust to the deck dorade vent location. The existing stern dorade thats 20+ feet of hose away seems inefficient.

The other, my son just suggested is to get a water cooled alternator. This never crossed my mind. A quick google search suggests they do exists! Now how big is the 190 amp water coold alternator i just goggled? Would I be able to use the engine raw water feed or would another pump and through hull be necessary? Does the alternator have its own internal pump? Would the 160 degree coolant temp keep it cool enough? I'm almost certain it would. Sure is a "cool" idea!

Looks like a bunch of high end cars have them already. The Hitachi model I was just admiring goes in an Audi R8. Looks like a small frame design but hard to tell by the photos. Appeaers to be externally regulated. Maybe I'll take a trip to check one out at the auto parts store.

 

[driftless]

David, in the -200 interior redesign, the engine seems sealed. Is there really only one vent with blower?

I know it's very different from the 381, in which the engine bay is open to the vast space below the cockpit, and passive ventilation is easy.

Any way to blow air in there, with another way for it to get out?

View attachment 47335...View attachment 47336
E381 engine bay, 38-200 engine bay

Since your photo is the under-companionway engine layout on the later 38-200s, I'll speak to it. It's different from David's under-sink engine.

The engine compartment isn't "sealed", but there is a "firewall" behind the upper half of the engine, where the engine compartment protrudes into the aft-cabin. Below that, it is open to the transmission, shaft, and fuel tank area under the aft berth. It's not directly open to the cockpit locker, but there is a hole in the wall to the locker for the cooling hoses (to hot water heater and over-flow tank) and for the vent ducts. My exhaust duct runs from the engine compartment proper into the locker, up to blower and out the starboard stern exhaust cowl. The intake duct is passive from the port stern cowl and runs forward to the fuel tank/transmission area. It's a much more direct run for the ducts than it would be to under the sink.

 

[Kenneth K]

Would the 160 degree coolant temp keep it cool enough?

To a point it would. But now the original cooling system is cooling both an alternator and the engine itself. Whatever susceptibility your engine had to overheating to begin with, the margin will be reduced if having to cool an alternator as well.

190A? Really. That's like running four stock alternators and is likely to make the engine run hotter to begin with.

 

[David Grimm]

My engine runs at 160 fully enclosed up with no fan on at all. It's cooled by the heat exchanger. Needs no other ventilation. However the compartment gets hot. Especially if I'm rapid charging the Lithium batts. The hot engine compartment is rough on the alternator. I have a Balmar 200. It's a 210 amp alternator.

It would be nice to keep the compartment closed when charging. Thus the exploration of alternate ventilation and alternator cooling methods.

I think ventilation is the way to go here. I wonder where I could find a dorade vent that would fit the port deck opening?

 

[Christian Williams]

As I recall it's the external smart regulator that doesn't like heat, the alternator always gets hot. Worth checking, if that's correct you could just move the regulator out of the engine compartment, as I did on the 32-3.

 

[SeaLore]

I just yanked my dead one out today and the hoses go next. if I were in warmer climes I might consider a fan out while running but like less is more. Now on to to the …..

 

[David Grimm]

A brief follow up. This excerpt is right out of the Universal Operators Manual.

4. Turn blowers off after starting or before starting to eliminate excessive battery drain, if preferred.

So that being said I guess no ventilation is needed.... untill you start charging large banks of lithium batteries.

Christian, I don't believe my Balmar MC614 has ever overheated. What were the symptoms?

As per the photos. There's no passive ventilation on the 38-200.

The wet locker houses my DC to DC charger. That door has to be open if the batteries are significantly depleted and the ambient temperature is high.

The deck dorade vent would be a useful engine vent. It never gets used otherwise. The factory vent hose runs right under the deck vent. Shortening and redirecting would be a simple upgrade. See the red arrow in the photo of the cabin vent hole. The forward dorades fit the deck port! Any suggestions on where to find an authentic match to the original vents?

 

[southofvictor]

Has anyone put a temp sensor into the compartment and compared ambient temps against suggested operating ranges? Seems that with the low cost of temp sensors that have recording function and are self powered it would be pretty easy to do.

Our blower ducting is trash and I’ve had thoughts of replacing it vs trashing it, but at this point it’s stayed on the bottom half of the project list. Interesting to hear what others are doing.

@David Grimm is that dorade vent OEM on the early -200 models or did you install it? Our boat doesn’t have any cabin venting other than ports and hatches and it’s been on my mind to come up with a venting plan for when hatches and ports need to be closed.

 

[Christian Williams]

I haven't had an alternator heat issue, it's just that they get pretty hot, especially if running at max output to recharge low batteries. Not an expert, but on the M25 I mounted the external regulator outside the engine box, so as to keep it cooler. Current boat has the regulator inside the box, and a mechanic felt that was not a problem.

Balmar says:

ALTERNATOR HEAT During operation, your alternator will become hot as a result of friction and the generation of inductive current. In some instances, particularly during extended periods of heavy load, alternator case temperature can exceed 200 degrees (F). If your system is operating with a Balmar multi-stage voltage regulator with optional Alternator Temperature Sensor (MC-TS-A), the regulator will automatically reduce field output if temperatures exceed set safe working limits. While this is an extremely effective protection for the alternator, it should not be depended upon as a part of normal operation. Correction of conditions causing overheating are strongly advised. Use extreme caution when handling the alternator or other engine components during or after use. Should your alternator become so hot that it emits a burning smell, or if there is indication of discoloration at the pulley or pulley shaft, shut off the alternator immediately and (once it becomes safe to inspect the alternator) check the tension of the drive belt. Under- and over-tensioned belts are the leading cause of overheating and alternator damage. See the Troubleshooting section, later in the manual, for alternator inspection guidelines

 

[David Grimm]

Yes. I have the temp sensors. I'm only pulling 60 amps. That's the maximum the Renogy charger will put out. With a clamp on Fluke DC amp meter I measure 59 amps between the input of the charger and the alternator, and 59 amps between the charger and the batteries. It's a good system. Proven and reliable. I just get worried about the heat build up in the engine compartment with no where for it to really go, so I leave the hatch open.

 

[Navman]

My blower stopped working about 4 years ago. I just replaced it this year and added a separate toggle switch. The old blower turned on automatically when you turned the ignition key. I replaced it in an effort to remove some of the trapped hot air in the engine compartment as well as the heat dissipating off of the engine. As I sleep in the aft berth, it is noticeably warmer there for a few hours after dropping anchor. I also though it wouldn't hurt to turn it on if I see the engine temp rising. It does put out a pretty steady flow of air. As it is now, it's there if I need it. If not, no harm, no foul.