Venturi tube to evacuate AC condensate water

[sailormed]

On our H38 we have an airco installed in the main cabin behind the mast. The condensate water is evacuated straight in the bilge. I prefer to have a dry bilge so I installed a big plastic water bottle (12 liters) to accumulate this water and keep the bilge dry. This works but you have to empty the bottle regularly.

The AC is seawater cooled and the Little Giant pump is continuously pumping seawater through the AC unit. The better solution would be to install a venturi tube in this seawater hose right before the through hull and evacuate the condensate water this way.

I have been looking for venturi tubes on the internet but have not found a venturi tube that I can insert in the 5/8” hose of my installation.

Have anybody succesfully installed this solution, and WHERE can I buy this simple venturi tube? Thanks for directing me to the right place.

[RaymondR]

That's a good idea if you can make it work.

You can make a crude venturi using pipe fittings.

[shimari]

Not a venturi pump, but this is what I used on my last boat
https://rectorseal.com/aspen-pump-aqua-series-group/

[Weatherbird]

These are the parts and prices from 2 years ago:

⅝" Barb to ¾" NPT Female Plastic
McMaster Carr 5218K739
Plastic Barbed Hose Fitting for Water, Adapter, 5/8" Hose ID, 3/4 NPT Female, 150 PSI
2x $2.49
https://www.mcmaster.com/

Venturi Siphon
Amazon B00I3VK6S4
Mazzei (784-PVDF) Gas/Liquid Injector - Kynar Black 3/4" MNPT
$45.98
https://smile.amazon.com/Mazzei-784-...dp/B00I3VK6S4/

½" Strainer
Amazon B00I3VK6S4
1/2" Hose Barb in-Line Strainer with 50 mesh Stainless Steel Filter Screen
$11.25

The strainer is no longer listed but it looks like this one: https://smile.amazon.com/Strainer-Tw...dp/B094NQNVMF/

I'm a live aboard in New Orleans so it sees a lot of use and the venturi has never clogged.

[Rumrace]

Prepare yourself for a whacky idea but how about a condensation tube, accumulator and one way valve all in one cheap?
It’s called a Tesla Straw. Lots of 3D printers have the data. I’ve printed them in TPU 95 which is a fairly rigid but flexible and soft plastic. Looks silly but it will work really well. A simple version of it fixes toilets also.

[Rumrace]

How a Tesla Valve works

[GreenWave]

hmm, can you not just run the drain tubing to your grey water sump???

[Sailmonkey]

I’ve been using one for at least the last 10 years on our AC condensate.

https://www.google.com/search?q=3%2F...&client=safari

The caveat is that it does introduce a restriction in the flow, so if you’ve got marginal seawater flow already this may be the final straw.

[Gerrit Coetzee]

I don't waste the condensation water. Once collected it is pumped to the fresh water tank. From there it goes through a reverse osmosis 7 stage filter to the drinking water tap. I use airconditioner condensation on my farmhouse, but there I drink it almost as is. I run it through a coffee filter bag once, because it is an open system and some dirt collects too.

[Jubilee39]

I don't quite picture it. It sounds like you are trying to set up a venturi using seawater system to suck freshwater out of the boat. What happens if the sea water pump stops, will it then allow sea water to flow back into the condensate sump and into the boat. Keep sea water out of the people tank.

[sailorbobdeb]

We have used the same method as Weatherbird since 2011 and it works great. Also added a small 12v pump with a toggle switch that can be turned on to pump out any residual condensation that may drip after unit is off and collect in the pan.

[Davidasailor]

Venturi is the principle behind the Mermaid Condensator - https://www.mmair.com/marine-divisio...d-condensator/. The Mermaid includes a check valve to prevent back flow from the cooling water circuit into the condensate pan. Relying on a check valve below the waterline for that purpose makes me a little nervous, but plenty of people use them successfully.

[Weatherbird]

If you use the parts I listed you also need one of these:

½" barb to ¼" FNPT Plastic
McMaster Carr 5218K734
Plastic Barbed Hose Fitting for Water, Adapter, 1/2" Hose ID, 1/4 NPT Female, 150 PSI
$1.86
https://www.mcmaster.com/

I used reinforced fresh water hose for the drain.

Also the venturi siphon has a built in check valve.

[S/V Illusion]

Been using a Venturi on our A/C condensate pans for many years. Works perfectly and no moving parts.

Any waterbed store has them in a kit intended to empty the bed and equivalent to but a lot cheaper than the Mermaid marketed type.

[ItDepends]

Not completely sure it would work with your system, but every chem lab has a faucet mounted venturi to pull vacuum in a quick and easy way. Might be too much restriction and flow rate from the little giant too low, but it is exactly what you want.