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Genset Exhaust Gas-Water Separator Add-on. Good Idea?

Discussion in 'Generators' started by Thisisit, Oct 26, 2020.

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  1. Thisisit

    Thisisit Member

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    My Westerbeke 8.0 BTD currently exhausts through a lift muffler and out through the hull, above the water line. Previous boats I've owned have had much quieter lift systems. I have been staring at the space in and around the exhaust hoses and muffler and am wondering if installing a separator like Centek's, for example would be worth the time, expense and scuffed knuckles. If I could add a gen-sep to the existing system (of course making sure it would work with the machinery) would I be happy with the result? I just find that the gen exhaust should be quieter since we spend much time in the cockpit which happens to be near the exhaust port.

    Has anyone had any experience with reconfiguring their generator exhaust or adding a separator? Looking for both pros and cons.
  2. SeaEric

    SeaEric YF Historian

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    The variable as I understand it is if you have the available plumbing route height to make a gen sep work.
  3. Thisisit

    Thisisit Member

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    Yes, most of the gen sep units must be above the water line. I have had a peek at one of the installation manuals and I do belive I have the height required. I think any unit would help quiet the noise. Just wondering how much they help.
  4. Alzira II

    Alzira II Member

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    I installed one in a 45 four winns. If you call centek and ask to speak with an applications engineer they can very helpful in confirming your below/above waterline setup. The installation I did the customer loved and had many happy years of use. Much quieter. I did have to install a new through hull.
  5. Capt Ralph

    Capt Ralph Senior Member

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    I have updated a few boats with the Centek unit.
    If the gushing/splashing noise bugs you, this is a plan.
    It takes room and another hole punched below water level or just inches below minimum light water line (with a sea cock).
    However, it just reduces the exhaust sound about 80%, you will still hear just a lil putter of the exhaust.

    Centek has some info on their web sight. Call the kids in Thomasville and they will pull their hair out to help you.

    https://www.centekmarine.com/product-category/water-separators/

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  6. CaptPKilbride

    CaptPKilbride Senior Member

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    I have not had any experience with the Centek products, but have used a lift muffler with a downstream gas/water separator designed and supplied by Soundown. If the Centek solution does not work for you, then Soundown might have another option that would deliver what you are looking for.
    Personally I was impressed by their solution, this was for a 12kw Northern Lights genset. Very quiet with none of the gushing of an exhaust mixed with cooling water.
  7. Thisisit

    Thisisit Member

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    Well, it does seem that I should give this idea more than just fleeting consideration. Thank you for all of your advice and experience. I think I will climb on board this fall and take detailed measurements and photos. Hopefully one of the manufacturer's products will fit the bill. An 80% reduction in noise is quite remarkable.
  8. Boatingnut

    Boatingnut New Member

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    The Centek type of solution works really well. My exhaust ports into the mains exhaust pipe, and all I hear is water running out. Very quiet.
  9. Thisisit

    Thisisit Member

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    Another interesting setup.
  10. Capt Ralph

    Capt Ralph Senior Member

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    Your gen-set water flows out the mains exhaust, or both the gen-set water and exhaust gas?
    This is an interesting set up.
  11. Thisisit

    Thisisit Member

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    Thanks for the PDFs Capt Ralph. I have been reading most of the product descriptions from Centek. I do like the combo unit. It is something that I think will fit in the space a little better than both the stock lift unit AND the separator. I watched a YT vid where a Centek inline muffler PN 1400003 was placed in between the genset and the water lift unit on a gas model Westerbeke. I don't think it was designed to do that but I haven't spoken to the engineers at Centek yet. If this is something that is possible on a diesel unit (with the higher back pressure), it is something to consider as well. I think there is enough room to insert the unit. Again, not sure that this would be advisable but it would sure make the upgrade A LOT easier.
  12. Capt Ralph

    Capt Ralph Senior Member

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    The installs I have preformed were mostly like in PDF#1, keeping the original muffler and just installing the separator.
    I have only installed one combo unit like in PDF#2. I felt just a hair (thin hair) quieter.

    There is a horizontal model that I just could not find the room for.
    The kids at Centek told me it was real quiet but as I found, a bear to find an installation location for it.

    The unit as in PDF #1 is usually the easiest to install and good on the budget.
    I feel it is as quiet than a hot air clothes dryer outlet.
  13. Boatingnut

    Boatingnut New Member

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    Genset water and exhaust are hooked into the starboard main exhaust. Maybe 12-18 inches from the outside exit. A/C is plumbed like that on the port exhaust. I really like those setups.
  14. mapism

    mapism Senior Member

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    I can't figure how your exhaust/discharge system is designed, because you said in post #8 that you can hear the water running out.
    Does your boat have submerged main engines exhausts with idle bypass, or dustbin style silencers with outputs above the w/line?
  15. Thisisit

    Thisisit Member

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    I would have thought that a set up like Boatingnut's would have some kind of impact on the genset exhaust, like back flow issues when the main was at high speed, unless its plumbed into the idle by-pass.

    My old Carver 3807 dumped all water and exhaust into exhaust "boxes" molded into the hull. The boxes had holes both under and above the waterline. Only the genny had a water lift muffler prior to the box. It was very quiet as was the trickle from the AC. The mains however had that un-muffled deep roar.

    I still miss that sound.
  16. Capt.Rob

    Capt.Rob New Member

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    The Soundown WaterDrop silencer would be a good addition. The lift silencer alone offers very little silencing. Can you please send a photo or drawing of your current system arrangement?
  17. Thisisit

    Thisisit Member

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    I don't have a current photo but the video at this link is a similar set up. The boat in the video is a gasser; mine is diesel.

    I did get a hold the engineers at Centek. He put me onto their double chambered water lift muffler. He says it raises the water twice in two chambers and apparently it is much quieter. Before I drop $550 USD on this, I would really like to see one in action. I also have to do some careful measuring before I settle on a refit. The separator addition may or or may not fit which is why I'm looking at the double chamber unit.

    BTW, the set up in this video is not recommended by buddy at Centek and probably would not be by those at Westerbeke either.

  18. Thisisit

    Thisisit Member

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    Update: I have measured the area and decided (with help from the Centek engineers) to go with the gen-sep vertical combo unit. The sound rating is on the “best” side of the scale. It will fit with millimetres to spare. The water outlet will be at or just below the LWL. It wasn’t the cheapest choice but hopefully the right one.

    Rough in starts in a few weeks. I will prep the hole and thru hull fitting. Will need a seacock to hold out the water until the unit arrives in June. Evidently there’s a world-wide resin shortage. Stupid pandemic.
  19. DOCKMASTER

    DOCKMASTER Senior Member

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    Let us know how you make out on the install and results please.
    I originally has an exhaust just like yours on my 8kw but my 20 kw went into the Stbd M/E tube about a foot from the end. I got a lot of noise from 8kw just above the waterline from the wet exhaust water splashing out. I also didn’t like the location as it was right where I like to put a fender. Several times had issues when the fender would block the exhaust. So I routed the exhaust from the 8kw into the port M/E tube just like my 20kw was on the Stbd. It is significantly better, I really can’t hear the exhaust at all now.
  20. Fishtigua

    Fishtigua Senior Member

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    As BN said Soooo much quieter. With our 2 gennies we used the Vetus set-up, you just hear a trickle of water.