Good or Bad Idea?

[Southpaw II]

Why couldn't there be a duct off the cabin heat system that allowed a small amount of heated air into the engine room? This could be a 3" flexible line hidden down the side of the boat in, say 29' and larger cruisers, with a slide gate to open and close it. When you're away from the boat on cold days, with the heat running, you could open the gate and allow heat into the ER. A small opening on the oposite side of the ER could allow cooler air to escape. This would keep the ER warm enough not to freeze, and would eliminate the need for a bilge heater. Load on the cabin heat unit would be minimal, I think.

Agreeably, not all buyers would even need this, but for those of us in temperate climates that keep our boats in the water all year, there is a need for it. It would reduce moisture in the ER, and could be closed when not needed.

 

[mwph]

Just off the top of my head, I'm guessing that the more experienced guys will chine in with...

A.) The run time needed to keep the bildge @ 40 or so would indeed be too much of a load on the system.
B.) The cost of a factory install would be far too much.

How hot would the cabin get in order to keep the bildge warm? In a boat my size the contents of my candy jar would melt!

 

[Southpaw II]

During the winter (now) my heat stays on 60F 24/7. When I stop by a couple of times a week, its warm and toasty, and the units seem to kick on/off every10-15 minutes. I just seemed that I could allow a little bit of that warm air into the ER.......I could see it taking less than 10% away from the cabin.

 

[osd9]

Bad Idea.

You definitely don't want the HVAC system vents from the cabin living area open to the ER. Read the CO thread.

 

[Four Suns]

5:23 AM... first food fight of the day.

The engine room needs to be sealed from the rest of the boat for obvious reasons. A heating vent would violate that basic requirement.

 

[osd9]

I threw the first eggs...I started it at 5:22.....:grin:

 

[Four Suns]

I've been up longer... "damn book"

 

[Four Suns]

Now there are people on this board, if I recall they own Four Winns products, that just drill holes in the salon floor to the engine room to run a temporary electrical cord for a bilge heater on a gas boat. How's that for a GREAT idea!

At least he'll know when his exhaust gets any leaking... He can use the cabin's CO detectors as an engine monitoring device.

 

[fwebster]

I have added a 120VAC circuit to my engine room and put 2 vapor proof sealed light fixtures on the engine room bulkhead. I leave 2 rough service explosion proof 60 watt light buld on all winter and they provide enough heat to eliminate condensation and I suspect help on very cold days. Its a cheap and easy add-on you might consider.

 

[berth control]

Frank -
When I was in Key Largo getting my boat worked on I asked the guy how he goes into the engine compartments of bigger boats in the summer without overheating himself. He said that a lot of the boats in the 40 foot range had the ability to divert the ac to the engine room, and he usually requested that option be used when working on warm engines. If they can run ac in there, they can run heat too, right? Maybe it is an option already, it seems like a good idea. I couln't find anything online with some google searches though, maybe my mechanic was wrong about that, he was wrong about my problem!

 

[Southpaw II]

What I'm talking about is a 3" flexible hose that stops, and is open to the ER. This would push warm air to the ER. The hose would have a baffle or a slide gate to adjust the amount of flow. The ER would vent to the outside....no possibility of CO.

 

[Four Suns]

What I'm talking about is a 3" flexible hose that stops, and is open to the ER. This would push warm air to the ER. The hose would have a baffle or a slide gate to adjust the amount of flow. The ER would vent to the outside....no possibility of CO.

Really? Why do you think that?

 

[Southpaw II]

Because the A/C would create a positive pressure forcing warm air into the ER. This is for use at the dock, remember? If I were running the genset or an engine, there would be no need to provide heat.

 

[jrirvine1]

The inline HVAC dampers that you are referring to do not completely shut off all air flow, as they are not designed to create an air tight seal in the duct.

CO could quite easily enter the cabin through the duct with the dampers.

My vote is very bad idea.

 

[Southpaw II]

The inline HVAC dampers that you are referring to do not completely shut off all air flow, as they are not designed to create an air tight seal in the duct.

CO could quite easily enter the cabin through the duct with the dampers.

My vote is very bad idea.

So noted. I would agree that it will never happen because if there is a possibility for it to go wrong and result in tragedy, builders shouldn't risk implementing it. Some lawyer (no offense to any reading) would make his retirement off the ensuing lawsuit.

 

[Four Suns]

Even though Jim doesn't know where the best crabcakes are, I agree with him. Additionally, don't think that because there is air flow from room A to room B that the gas can't propagate from room B to room A. It can. The air would have to move faster than the gas can mix and travel... So unless you have a sonic blower on your AC system (I don't know what the actual speed would have to be), it's not going to prevent it from coming upstream completely.

I think your basic assumption is that the air flow is faster than the gas is mixing and traveling... which I doubt. So I vote "Bad idea".

I am pretty sure it would also violate some boat building guidelines by not having the engine room properly sealed from the salon. I would think fire propagation may also be of concern but I'm guessing there.

 

[jrirvine1]

And I always disagree with Gary as a matter of good practice, but in a life and death consideration, I am forced to concede

 

[Nehalennia]

Because the A/C would create a positive pressure forcing warm air into the ER. This is for use at the dock, remember? If I were running the genset or an engine, there would be no need to provide heat.

I agree with the advice you're getting. The easiest element I would consider, is the "what if I forget".
If there is a scenario or idea that you can forget to perform an action that can possibly put you at risk, it's a bad idea.

 

[osd9]

And....aside from the CO aspect, don't forget the 'kaboom' issue on gas boats. Everything in your cabin will need to be spark proof......even your alarm clock.

 

[comsnark]

The basic concept: Seal the engine room from the crew areas! Makes really good sense.

But thinking about it. . .my boat isn't really built that way. I am able to pass wires under the gunwale all the way from the dash to engines. The dash is seperated from the head by a simple drop down panel. I remember snaking a sonar transducer cable through this path 2 years ago without too much effort.

Now. . I am not disagreeing with anyone in this thread, but I would like to ask a question: How much CO do you suppose is in an engine room? The only source for CO is engine exhaust. Engine exhaust is routed OUTSIDE the engine room. The engines simply won't work right if you fill the engine room full of exhaust. Now, it is possible to suck exhaust back into the engine room from the transom, simply because the engines are drawing air into the space from the rear quarters of the boat., but I suspect because of the air aspiration of the engines, I bet the engine room is better ventilated than the cabin of the boat.


Any how. . .there was far too much agreement in this thread. Even though I agree with the advice, I thought I would stir it up a bit.



Also. . note where the air intakes are for a typical car ventilation system: In both my cars, they are right under the hood in front of the windshield. If CO/engine exhaust were coming out anywhere in the engine compartment of a car, at the windscreen would be a horrible place for cabin air intakes.

As for gas fumes. . . yeah. .that is also serious. But gas fumes require much higher concentrations to cause a problem than exhaust.

I am not advocating opening a connection here. . . the engineering judgement to not do this is sound. I am just saying it may not be as bad as, say, putting a honda generator in your cabin or putting the baby basket in the engine room.