Generator Question (on the swim platform)

[agallant80]

OK so not to insight a riot here or get people worked up about the dangers of CO but I have noticed a large crowd that will sleep with the built in generator running and a large crowd saying that sleeping with a protable generator on the swim platform is asking for death to come visit. My questions are:

How is a built in generator safer? They both have to exhaust some place (im not talking about heat or anything just the C0).
Do you sleep with your built in generator running?
Do you sleep with your portable generator running?

Reason I am asking is because I was in the no sleeping with the portable generator crowd but after a few things I am starting to change my mind. Reasons I am starting to change my mind are:
1. I have 3 C0 detectors int he cabin, One in the front, one in the kitchen and one in the sleeping birth under the cockpit
2. Honestly its getting hot as H-E-double hockey sticks out here in NC during the night. Cooling down the cabin and running a fan does not seam to help much.
3. None of my detectors have ever gone off, they have all been tested and work but I have ran the generator for hours on the platform and not once has any of them made a noise.

 

[haulnazz15]

Re: Generator Question (on the swim platform)

The only issues with the portable gensets that I know of are:

1) minimizing the CO risks related to exhaust fumes entering the boat/cabin due to open windows/vents, and;
2) possible noise level complaints from nearby neighbors

Most of the portable Honda generators don't seem to be any louder than the marinized units, and the issue of being spark protected is moot as long as the genset is placed on a swim deck or somewhere away from any possible fuel source. (i.e. don't place it in the bilge). As long as you have multiple CO detectors aboard that are operational and tested each night before sleeping, I don't see the problem. Above deck isn't really any more dangerous than marine gensets as far as I'm concerned, as long as the exhaust it routed outside the boat and downwind.

 

[JoLin]

Re: Generator Question (on the swim platform)

From what I've seen here and on another forum I sometimes visit, the question of whether or not to sleep with one running seems to depend on where you live. Southerners seem to do it often and wouldn't have it any other way. Some run it before they hit the sack- cool down the cabin then shut off the genny.

Nobody I know personally (coastal northeast) would ever sleep with one running, but we don't (usually) have the heat issues some others have. IMO, if you're gonna do it you need to take as many precautions as you can before you roll the dice.

And one other point. If you're overnighting in a raftup with other boats, DON'T run it overnight. You could poison the folks in another boat.

 

[Fireman431]

Re: Generator Question (on the swim platform)

I sleep all the time with the genset running, but there are a few precautions that we take at ALL times.

1) Co detectors are required equipment anywhere someone might be sleeping (staterooms, salons, bridge enclosures, etc). They have to be hard wired as well as have a battery backup, and have to be in date (most are 5-7 years replacement). Test them and ensure your safety. You don't want to wake up dead.

2) Boat must be anchored in an open area (no overhangs, low level trees, etc). The CO and other exhaust gases have to be free to dissipate.

3) No open hatches or portholes. This should be the job of the captain to verify that his/her vessel is air tight and there is no possibility of CO entering the sleeping areas.

4) Any other boats in the area should be made aware that a genset will be running diring the night. The only thing that comes in second to killing yourself is killing some innocent party next door.

All that being said, it is a very safe procedure if the rules are consistant and followed each and every time. We have spent countless nights with the AC nice and cold (Florida gets friggin' hot), full 110v for fridge, TV, and of course, the blender.....and never had any problems. Remember to turn off your blowers. The blower can pull in exhaust gases and they can seep in from the bilge. This is another reason quality CO detectors are a must. Aside from that, most generators are pretty quiet, especially once you're in that cabin and close the doors. That mellowed hum will help you sleep.

Don't be afraid of using the genset...that's why you have it. Just take the necessary steps to make it safe for you and those around you.

 

[H20Rat]

Re: Generator Question (on the swim platform)

How is a built in generator safer? They both have to exhaust some place (im not talking about heat or anything just the C0).

Some built in marine gensets have their exhaust exit under the waterline. The exhaust is also watercooled with a waterjacket, so the gases are much cooler. That in turn keeps the gases at the waterline. A non-built in doesn't have any exhaust cooling, so the gases rise immediately after leaving the tailpipe. Depending on winds, its not impossible they 'station wagon' their way right back into the cabin.

 

[smokeonthewater]

Re: Generator Question (on the swim platform)

yep, what he said.... water cooled exhaust at say 125 deg is MUCH less likely to rise than dry exhaust at say 750 deg

ALSO and this is huge... much of the CO in the water cooled exhaust will be absorbed by the water before ever leaving the pipe

 

[rfdfirecaptain]

Re: Generator Question (on the swim platform)

Hello again OP.. Great question you pose. I am on Kerr Lake now with mine running. It's just as hot outside today as you described, but very comfy in this cabin particularly with 2 fans circulating the air around. I will post again with a photo of my genset running. You've already seen my comments about this in another thread. So far I would agree with all posts here except for the information about "rising" CO.

The vapor density of CO is .97 thus it has about the same buoyancy as air. At dead calm any "rise" in CO would be nominal. Then you have to factor in how the increased humidity (particularly at nighttime) will affect the "rise" as high humidity weighs ALL gases to some extent. Under the worst circumstances on the water you can expect CO to move laterally. My kids don't ever swim with the genet running. Under the best circumstances CO will dissipate with a slight natural breeze. As another poster said it is important to close all windows at the waterline, be aware of a station wagon affect and be mindful of others in a raft up situation.

I'm not sure about the comments concerning "cool exhaust" being absorbed by the water. If there is a condensation process taking place in the exhaust pipe, much like that of a liquor still, I would buy that if it weren't for the fact that the solubility of CO in H2O is negligible. Generally speaking though, what is happening is water is acting as a "scrubbing agent". The CO is being dispersed into a huge volume of water. Here is an example of an asphixiant chemical made safe; in some aplications leaking anhydrous ammonia can be scrubbed in a tank of water leaving behind some great-harmless fertilizer. I don't know for sure, but I suspect the that in this case the CO will at some point rise to the surface in smaller, less persistent and less harmful amounts.

A few things: Have redundant CO detection regardless of whether you use a genset and research the matter thoroughly first. Yes CO is very deadly, but this is not living on the edge. It's just like every other harmful chemical we manage safely, mainly GASOLINE vapors. If you know and understand the characteristics of CO and take all safety precautions... then you can say the most dangerous thing about your trip was not the genset, but rather the drive to get where your were going boating.

 

[rfdfirecaptain]

Re: Generator Question (on the swim platform)

.

As you can see we are fishing on this trip. I have a genset, a cooler that is a bait tank and a sodium high pressure light. Note the horizontal black tape behind the bait tank that seals off the exhaust vent from the engine/bilge compartment. I seal it when the genset is running to prevent gennny exhaust from blowing back in that opening.

 

[H20Rat]

Re: Generator Question (on the swim platform)

So far I would agree with all posts here except for the information about "rising" CO.

The vapor density of CO is .97 thus it has about the same buoyancy as air. At dead calm any "rise" in CO would be nominal.

Forgetting about Charles's law? Yes, when both gases are at STP they are relatively similar. Problem is, they aren't both at STP. The CO coming out of the exhaust pipe is hot, and therefore substantially less dense. Fill a thin plastic bag with hot exhaust, and it rises. Pretty simple.

[Some] Built in gensets have waterjackets, water in the exhaust, and may also dump their exhaust under the waterline. All three of those cool the exhaust quite dramatically.

 

[smokeonthewater]

Re: Generator Question (on the swim platform)

The comment about rising had nothing to do with the CO but rather the temp... exhaust gas at several hundred degrees will be lighter than the ambient air and will rise... water cooled exhaust being at a much lower temperature will be much less likely to rise.

Not saying it can't be safe... just since the O/P asked why a marine genny is safer I wanted to explain why...

 

[agallant80]

Re: Generator Question (on the swim platform)

Keith,

I wish I was on the lake right now. Its so nice outside. What was I thinking going to the office today. One thing I did not think of was sealing the vent to the engine compartment, something to consider. I have seen one one of the sailing formims where some people add about 4 feet of exhaust hose to their portable generator and throw the hose off the back of the boat. I have been thinking of doing that, I just need to see if I can get some hose around my generators tail pipe or not and of course buying the hose which is about $12/foot.

 

[JoLin]

Re: Generator Question (on the swim platform)

I have seen one one of the sailing formims where some people add about 4 feet of exhaust hose to their portable generator and throw the hose off the back of the boat.

Is that done with something like the little Honda generator? It would surprise me if that little motor could overcome the back pressure of exhaust routed into the water.

 

[rfdfirecaptain]

Re: Generator Question (on the swim platform)

I'm going to have to look into that "cooled exhaust" thing. I appreciate the additional info and I don't mind learning a new trick.

OP, we're gonna be between Ivy Hill and Keats point (near the dam) until Thursday. We fish all night... Troll lead core in the morning and evening if we're not too sleepy. . Come me on up and join us. As for the extra hose thing... I looked into that too when I bought my genset. Two problems I found. Depending on how much "extra" hose you add... you can increase the back pressure on the exhaust... I'm not a mechanic but my friends who are tell me that could cause engine problems. I was willing to take that chance... But the antagonist factor for me was... OK, so I move the exhaust farther away from the boat... Just how far can I possibly go and how's this going to affect the lateral movement of CO once it is finally exhausted? So, I decided to get more proactive on my safety and less curious about a one shot deal to cure my ill.

 

[smokeonthewater]

Re: Generator Question (on the swim platform)

seems to me like the exhaust hose would just melt

the "cooled exhaust" is on an installed marine genny...... while i guess it could be possible on a portable it would take away a good amount of the "portable" factor

 

[agallant80]

Re: Generator Question (on the swim platform)

I would love to make it up to Kerr lake but I have a few customer deliverables due this week and the little lady and I are going straight to Oak Island after work on Friday.

 

[Cptkid570]

Re: Generator Question (on the swim platform)

Does a little honda generator really put out that much exhaust that it could pose a danger if the generator is outside of the boat? What if he plugged a small fan into the generator too and pointed the fan to blow the exhaust away from the boat? Or, only had a front anchor down so that the wind would always blow the exhaust behind you?

I'm not second guessing, I was just surprised to hear that a small generator would pose such a threat. And, that said, I would think that a built in generator would be much more dangerous than a generator mounted on the swim platform. A built in generator is putting spark, gas intake, and outgoing exhaust into your bilge (where gas fumes could be). Portable generator keeps all that outside of the bilge

 

[rfdfirecaptain]

Re: Generator Question (on the swim platform)

Or, only had a front anchor down so that the wind would always blow the exhaust behind you?

I usually anchor in areas where there is enough open water around me allowing my boat to catch enough wind and wakes that my boat will sit back on a taught rode. Thats when I feel most confident that all the CO I am producing is being dispersed downwind. When there is dead calm I am much more alert for potential issues.

You know I would love to see the stats on how much CO is produced by my generator at idle and at max RPM... As compared to the CO production of a campfire that with a sustained and specific BTU...

 

[smokeonthewater]

Re: Generator Question (on the swim platform)

Does a little honda generator really put out that much exhaust that it could pose a danger if the generator is outside of the boat? What if he plugged a small fan into the generator too and pointed the fan to blow the exhaust away from the boat? Or, only had a front anchor down so that the wind would always blow the exhaust behind you?

I'm not second guessing, I was just surprised to hear that a small generator would pose such a threat. And, that said, I would think that a built in generator would be much more dangerous than a generator mounted on the swim platform. A built in generator is putting spark, gas intake, and outgoing exhaust into your bilge (where gas fumes could be). Portable generator keeps all that outside of the bilge

When CO kills you it's presence in your blood is measures in parts per million... it doesn't take much

the built in generator does NOT put anything in the bilge that isn't already there on an inboard or I/O boat... the exhaust is routed outside the boat...

the bilge blowers are run to evacuate any fumes and the unit is designed specifically to be run in that environment

 

[Fireman431]

Re: Generator Question (on the swim platform)

Just as little clarification...Most marine generators have their water cooled exhaust at or near the waterline, but not below it. The motion of the boat under way would force water up thru the discharge hose (even with a siphon break and water muffler installed) and create a hydrolock condition in the engine.

 

[rfdfirecaptain]

Re: Generator Question (on the swim platform)

Just as little clarification...Most marine generators have their water cooled exhaust at or near the waterline, but not below it. The motion of the boat under way would force water up thru the discharge hose (even with a siphon break and water muffler installed) and create a hydrolock condition in the engine.

And the plot thickens...So the exhaust is not "scrubbed" in the water. OK, if you know do you care to elaborate on how this system would be safer than one sitting on the swim deck? Seems to me it's not any safer.