Venturi tube to evacuate AC condensate water

[Blue Ribbon]

Been using Mermaid condensator for 15 years. Keeps bilge dry. I have a small in line filter to keep the output tubing clean. Filter needs cleaned 2-3 times a season. When bilge has a little water in it, time to clean filter. Very easy install and very little maintenance.

[ItDepends]

I do like the idea of a venturi to keep things clean and dry. Elegant. The only issue is you NEED to think ahead and set things up so when the venturi clogs, the overflow is managed in an elegant way.

It is a matter of "when" not "if".

[S/V Illusion]

Originally Posted by ItDepends

I do like the idea of a venturi to keep things clean and dry. Elegant. The only issue is you NEED to think ahead and set things up so when the venturi clogs, the overflow is managed in an elegant way.

It is a matter of "when" not "if".

If the Venturi clogs, which I have never hear of happening, the worst thing that happens is some condensate can accumulate. If the cooling water line clogs, that’s an issue regardless

[KadeyKrogen38]

Marine Air has been selling this device for many years. I use one on my boat. They call the unit a Condensator, I believe.

Inserts into outlet sea water discharge and provides suction to remove condensate along with discharge water.

[OS2Dude]

i added a venturi to our Webasto FCF AC. I tried several, but got one similar to this garden fertilizer injector to work. I had to put a 'bypass' loop in to prevent the venturi from blocking too much of the flow through the AC itself. Works great.

(The black piece [Not the black corrugated electrical conduit] is the venturi, the clear hose over it is the 'bypass'. It comes from a 'T' fitting and back into another 'T' on the other side.)

[sailormed]

I want to thank all posters for the ideas and solutions provided. Thank you all for providing me enough ideas to get to a practical working solution.
I will update later with the implemented system.

[Sailmon]

Our air conditioning condensate pan drains to our shower sump box which is drained by a pump & float switch.

[showmanship]

I personally would NOT use a venturi on AC- not only does it restrict cooling water but could cause your boat to sink. If your boat has a shower, that would be a better place to route the condesate. If not, I really like the idea of collecting it for reuse. Remember it's distilled water so could also be used for battery top-off, in addition to "farmhouse coffee", drinking after filtering, etc...

[ItDepends]

Originally Posted by showmanship

I personally would NOT use a venturi on AC- not only does it restrict cooling water but could cause your boat to sink. If your boat has a shower, that would be a better place to route the condesate. If not, I really like the idea of collecting it for reuse. Remember it's distilled water so could also be used for battery top-off, in addition to "farmhouse coffee", drinking after filtering, etc...

Seriously BAD advice. Do not drink condensate from your ac unit. It is full of dust and mold. Even after filtering, just no.

[showmanship]

I agree-DONT drink the water-! Withdrawing my comment above relating to drinking condensate water. Only in dire emergency. However, a good point relative to mold- always make sure to clean evaporator regularly or use tabs to reduce mold. You don't want to be breathing the mold either. A good way to prevent mold in evaporator is to run fan only for a few minutes prior to shutting AC off.

[Artey]

Originally Posted by OS2Dude

i added a venturi to our Webasto FCF AC. I tried several, but got one similar to this

I had to put a 'bypass' loop in to prevent the venturi from blocking too much of the flow through the AC itself. Works great.

Thanks for the idea, I've had a venturi from the intial install of my Webasto FCF but flow has never been what I thought it should be. This has to be the reason why. I'll think I'll get a two T's like you explain and plumb that in. Do you have a downstream shutoff on your outflow anywhere to stop backflow due to heeling when sailing? I put one on mine. I imagine I could just incorporate that into the downstream T for the bypass of the venturi.

[JayH]

I have used Venturi tubes on 5 Webasto air conditioners for the past 10 years. I wouldn't have it any other way. Prior to the Venturis I had terrible problems with algae and clogs in gravity drains causing flooding.

I use the 1/2" models shown here (but without a check valve) adapted for 5/8" tubing for Webasto 6K and 16K units. Have never had any flow issues requiring bypass. I do have multiple air conditioners sharing oversized pumps so I may have more flow than standard. It works for me.

I'm not sure if I like the check valve idea. I suppose it would be a positive addition as long as it doesn't reduce suction. I can no longer find the model I have without the valve, but the valve can be removed from those that have it.

I tilt the air conditioners slightly so water drains toward the corner where the condensate line is. Probably a good idea whether you have a Venturi or not.

The condensate lines make a slurping noise when there is some water present and the Venturi is sucking. Like a straw at the bottom of a milkshake. It may be possible to avoid that. It doesn't bother me because it means cold air.

With the Venturis introducing air, the overboard discharge is kind of foamy with little bubbles. I have oversized thru hulls for discharge to achieve a nice gentle pour instead of the violent squirt you see and hear out of the side of most boats. The foaminess makes it even quieter.

In big waves I've had salt water work its way up the discharge and condensate lines to fill and overflow the pans. I have to remember to close the air conditioner outlets when sailing offshore.

My Venturis clog often with hard growth (barnacles or mussels depending where I am) that must be growing in the hose and letting go from somewhere upstream. The clog manifests as an overheat, a condensate backup, or even reversal of the condensate line with salt water. The first case causes the unit to shut down with an error code, the second sets off alarms I have installed in the pans (float switch, piezo, and 9V battery), the third has happened to me twice in 10 years.

I intend to install strainers immediately in front of the Venturis. Occasional cleaning should prevent the clogs.

Check valves might prevent the backflow problem. When it happens the pans overflow so fast that the alarms can't alert me in time to prevent it making a mess, but at least I've been there to deal with it quickly. Because I use multiple units per pump, even if one air conditioner shuts down due to overheat the others can keep demanding water.

I am in the process of changing my float switches to a higher tech solution. I am using YoLink water sensors and a "finger" device to trip the air conditioning breaker if there is a problem. That way all the aircons shut down immediately to prevent flooding even if I'm not home. I also get notified via phone alert.

https://www.amazon.com/YoLink-Sensor.../dp/B08T8X4XWN
https://www.amazon.com/YoLink-Finger.../dp/B08N9WSYPJ

Writing this down, it all sounds like a lot of trouble and it is. But cold air is worth it.