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doctom 05-15-2007 10:16 AM

AC condensate drainage
Currently my AC is under the vberth in the bow. A hose drains the condensate pan into the bilge where an auto pump puts it overboard. I hate having a wet bilge so I wonder if anyone else has come up with a better system. I thought putting a wet/dry pump set on a switch with the switch in the pan but the sides of the pan are very shallow and i dont know if the water level would get high enough to trip the sensor before the water gets high enough to be pushed out the vent by the fan.

One thought i had would be to put a venturi valve on the drain for the pan. When the AC is on a water pump is pushing water thru the coils so maybe if i put a venturi valve on the line it could pull the condensate out of the pan. know the draw would not be strong but there isnt a lot of water that needs drained continuously.

Any thoughts from people who have done this before?


sailingdog 05-15-2007 10:33 AM

Why not just put a small shower-sump type setup in the bilge, and have the A/C unit drain to that... it's pre-wired with a small pump...

Boasun 05-15-2007 10:50 AM

Have a sump for the drain with a small pump. the sump would be separate from the rest of your bilge. Maybe a tupperware tub (they come in various sizes and shapes) could be used for the sump or something similar. And then your bilge will be not be wetted by the A/C drain... and if the bilge is still flooding then look for other problems.

The sump's nautical term is a Rose Box.

HerbDB 05-15-2007 02:37 PM

doctom 05-15-2007 02:56 PM

that is exactly what i had in mind...i wonder what the flow rate would need to be. we used those types of fixtures in organic chemistry labs...i dont see why it would be 2 hundred dollars though. i am looking for the faucet adaptors with ventur valves on the side arm for suction, they have got to be cheaper. thanks for the advice!


hellosailor 05-15-2007 03:01 PM

Mike, how much condensate does it make?

And is that small enough so that you could just stick a blivet (flexible tank, wine bladder, milk bladder, etc.) in the bilge, let the condensate run into the blivet, and then empty it manually once a day? Or run a very small bilge pump into the blivet to empty it too?

Or possibly run the line into a forward head sink drain?

Cruisingdad 05-15-2007 03:21 PM

$200!!!! Dream on!!

I will try and not regurgitate the info given above, but basically coming out of the pan you have it run into a catch basin with a float switch and small bilge pump. It is a simple design. THe hardest part is figuring out where you are going to discharge and running the discharge line.

I personally think that getting the water out of the bilge is a must. Not because it will really do any damage down there (this was debated in an old thread about a year ago), but because if you always have a wet bilge, how do you know where the water is coming from??

I have never seen that venturi water drain before... but $200 seems high to me! On a positive side, it would be a lot easier to install. On a negative side, it is one more potential area for failure and expensive.

Here is an idea that would take care of your problem and add a safety measure to your boat. Run the drain hose all the way to the bilge. Go into a shower sump system, like the one here: West Marine: Multiple Port Sump System Product Display

Instead of using a sealed shower sump system (as is popular), open it with holes in the top of the box. Thus: you have a condensation drain AND you have added a big safety measure to your boat. If the main bilge pump fails or becomes overloaded, you have a secondary pump. It wont cost you any more to do it this way, will keep your bilge dry, and will add a safety measure.

- CD

PS I am putting a patent on this idea - so don't steal it!! (HAHA)

doctom 05-26-2007 07:47 PM

thanks for all of the help guys!
i got this for arund 20 far it has worked fantastically! i have a dry bilge and a dry condensate pan.
PVC Plumbing Fittings - PVC Valves/Venturis/Unions - Turbo Venturi Valve (1/2 Inch) :

i am sure that someone has had this idea before...and i am cautiously optimistic. if it turns out not to work, i'll let y'all know. but for now, my AC (which in south tx runs 24/7 and makes copious amounts of condensate) is running well, and it did not noticeably diminish the cooling outflow. now my bilge is dry enough to scrub out and epoxy and paint.


doctom 06-15-2008 09:44 PM

Well, here is the update as promised, I have been using the 20$ venturi valve for 2 years and have had zero failures. It keeps my condensate pan dry and has zero moving parts. I cleaned it out this weekend while PMing the AC unit but it didnt have any growth or obstructions. I think this piece should come with every AC unit as it eliminates the need for any pumps or sump drains and requires only one drainage hose.


negrini 06-15-2008 10:10 PM

Ouch Doc, this is really simple. I suffered for years with a wet bildge. Thanks for posting your results, and send us pics of your project.

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