New AC - Questions about drain pan

[PamlicoTraveler]

I have ordered and will be installing a new 16btu AC, replacing my old Cruisair with a Webasto.

I now have a waterline from the drain pan to an aft shower sump that then pumps it out of the boat. It's always been a nagging issue, the line gets clogged or the pump doesn't pump, so it seems it has been an unsatisfactory arrangement. Now is my time to address it.

1.) Is there a tiny bilge pump that can fit in the drain pan itself and pump to a sink drain nearby instead instead of running a 10 foot line to a shower sump. I've never heard of anyone doing that, but it seems like it would be doable, somehow.

2.) How controversial is it to just drain the pan into the bilge? I only use the AC at dock when I am here, or occasionally with a genset. It wouldn't be an unmonitored water flow. AC condensation water should be totally clean, so it's not like draining a shower. What is the negative of doing it this way?

I am interested in how others have handled this. Thanks for any thoughts.

[sailormed]

The easiest solution to get that water out of your boat is to install a small venturi pump just before the cooling water outlet through hull. It will always suck up all your condensate water. Just be aware that you should route the sucking line somewhere higher then the (heeled) waterline so as not to create a siphon filling up the bilge with seawater.
You can find these venturi pumps at sellers of waterbeds, they are used to empty waterbeds.

[PamlicoTraveler]

I'm not familiar with a venturi pump, but will check into it...Thanks

[US1Fountain]

Mermaid Condensator. A little costly but it'll keep your drain pan empty. My previous boats AC unit was mounted on a base, with a sump box under neath it. I installed a drain tube in the AC pan's bottom to allow the condensation to drip into the sump box, and then located the condensator's siphon tube in the lower corner of the sump box. That way the AC pan will never have any condensation in it to splash around. And if for some reason the Mermaid Condensator got plugged up and didnt suck up the condensation, the sump pump would simple pump the water out. I never had an ounce of trouble with the condensator, which I've had 2 in my lat 2 boats, and never a drop of water left in the drain pan or sump box.

[StuM]

Re option 2.


Our aircon drains into the starboard hull and is pumped out as necessary. Not a problem - it's clean fresh water.

[ranger58sb]

Originally Posted by PamlicoTraveler

I now have a waterline from the drain pan to an aft shower sump that then pumps it out of the boat. It's always been a nagging issue, the line gets clogged or the pump doesn't pump, so it seems it has been an unsatisfactory arrangement. Now is my time to address it.

What clogs, and why? Why doesn't the pump pump? AC condensate should be clear and shouldn't be causing any issues in the shower sump.

Maybe a solution is to solve the shower sump issues... especially since (I'd guess) they'll likely be at play when you shower as well... so impacting more than just AC drainage.

??

-Chris

[a64pilot]

Both of ours drain into the shower sump, which on an Island Packet look suspiciously like a Kitchen trash can

Anyway that has a tendency of keeping the shower sump clean, as we pretty much never shower in the boat. A good diaphragm pump mounted above the sump and an Ultra Switch and you should have a decade or two with no problems.
I was looking at the Venturi pumps myself, but by their nature they have to have a restricted orifice to form a low pressure area to create suction. If your clogging an open hose with stuff, this restricted orifice doesn’t stand a chance, it will clog even faster.

[mvmojo]

It's a myth that a/c condensate is clean. The assumption is that since it is distilled water from moisture in the air, it's pure. However, consider the source. It's water that is condensing on the condenser coil and dripping into the drain pan. The condenser coil has air flowing over it, along with all the dust, bacteria, mold and mildew in that air. The dust that's carried away with the condensate water is typically what causes clogs in the drain hose. An air filter can help, but it won't totally eliminate the airborne particles. And, many boat a/c's don't use air filters. although I'm not sure why. I added air filters to all three of our a/c units and it made a big difference in keeping the coils clean. But, since the water really isn't "clean" or "pure", it shouldn't be allowed to drain into the bilge - it's just a potential source of mild and mildew.

If you've got a sink nearby, why not tee the drain line into the sink drain, if your drain pan is high enough to allow gravity to do it's job? I have all three of my units plumbed into the galley sink drain. They're all mounted high enough that the lines run continuously down hill. Been working fine for the 17 years we've owned the boat. And, if you don't have an air filter on the condenser coil, add one and change it periodically. That will generally keep the drain hoses from clogging.

[captmikem]

My experience with AC drains,

I drain them into the bilge, but put a loop in the drain which makes a water lock so odors are not pulled from the bilge and blown into the cabin. Once ever month or two pour a small amount of diluted bleach into the pan to kill any bacteria, mold etc.
I have done this for years on many boats and have had no problems.

I once ran the drains into a shower sump which turned out not to be a good idea as occasionally the drain would get clogged with soap etc.

The small amount of water flowing into the bilge is not a problem and tends to keep the bilge clean and the occasional bleach helps to keep it fresh.

M

[CHRIS V CLEMENT]

I love my Mermaid Condensator !!!!

[Cadence]

Alga in an AC condensation pan drain is a problem. A little bleach occasionally solves it.

[mvmojo]

Rather than pouring bleach into the pan, consider buying some swimming pool chlorine tablets. Put one (or a piece of one) in the drain pan. It will dissolve slowly keeping the condensate mold/mildew free. The condensate will always be "bleached" and your bilge will smell sweeter. I've also heard of folks putting washing machine detergent tablets in the drain pan. The soap also helps keep the bilge clean. On our sailboat, we used to throw a handful of detergent power into the bilge every few weeks. The little bit of water sloshing around dissolved the soap and kept the bilge clean and sweet smelling.

[a64pilot]

I wouldn’t keep a swimming pool tab in there, as as you say it’s constantly chlorinated, so much so that it will likely rot the pan or evaporate coil.
Maybe a dishwashing machine tab, they don’t suds and do keep things clean, it’s what I used in our powerboats. I learned that trick from jet skis.
Regular detergent can cause suds of course.

[Cadence]

Originally Posted by mvmojo

Rather than pouring bleach into the pan, consider buying some swimming pool chlorine tablets. Put one (or a piece of one) in the drain pan. It will dissolve slowly keeping the condensate mold/mildew free. The condensate will always be "bleached" and your bilge will smell sweeter. I've also heard of folks putting washing machine detergent tablets in the drain pan. The soap also helps keep the bilge clean. On our sailboat, we used to throw a handful of detergent power into the bilge every few weeks. The little bit of water sloshing around dissolved the soap and kept the bilge clean and sweet smelling.

The chlorine tablet sounds good. It may pay to place it in a plastic cup with holes on the sides so the tablet does not contact the pan?

[ranger58sb]

Originally Posted by mvmojo

It's a myth that a/c condensate is clean. The assumption is that since it is distilled water from moisture in the air, it's pure. However, consider the source. It's water that is condensing on the condenser coil and dripping into the drain pan. The condenser coil has air flowing over it, along with all the dust, bacteria, mold and mildew in that air. The dust that's carried away with the condensate water is typically what causes clogs in the drain hose. An air filter can help, but it won't totally eliminate the airborne particles. And, many boat a/c's don't use air filters. although I'm not sure why. I added air filters to all three of our a/c units and it made a big difference in keeping the coils clean. But, since the water really isn't "clean" or "pure", it shouldn't be allowed to drain into the bilge - it's just a potential source of mild and mildew.

Yes, "clean" is a relative term in this context... but it ought not to be so "thick" it clogs a shower sump, even if one only cleans the condenser coil not very often.

(Have to say, ours hasn't usually suffered much visible build-up of yuck. And that's without much cleaning effort... but then the boat came with cleanable air filters on each return...)

We have to periodically clean our shower sump and especially it's strainer well before AC condensate would cause any clogging.

Our bilge is usually dry. If it's not, I go searching for why not.

-Chris