I learned something new today, and that leads me to another question.

[HanBan]

A couple of weeks ago I thought it might be a good idea to leave the AC on in our boat, figuring that it might help with the smell (which I still haven't had time to track down).

However, when we popped by the boat today, the bilge was full of water.
We looked everywhere trying to find the source of the water; throughhulls, holding tanks, checking the hull, etc. It turned out to be condensation from the AC running in the cockpit locker.

Today I learned not to leave the AC on if I’m not there.

Question: Have any of you fitted a float switch to your bilge pump? If so, is it tricky?

You guys rock by the way. It means the world to me knowing that there are like minded sailing people who are always willing to share their knowledge. Please know that I never take your time and input for granted.

 

[BigEasy]

Hannah,
Sounds like whoever installed your AC ducted the condensate drain into the bilge....not good. Wet bilges will cause odors and there is speculation that wet bilges may facilitate formation of osmotic blistering on the hull because the hull gets water saturation from outside the hull (for obvious reasons) and from inside the hull with wet bilges present.
There are two quick fixes that I am aware of that will keep the bilge dry.
1. Install a dedicated shower type sump in the bilge. These can be purchased from the major chandleries for about $100.
Its simply a small container with a bilge pump and float installed. Duct the condensate drain line into the sump and
another line overboard. Also need to install an anti siphon loop to prevent water from draining back into the sump
when heeled over for long periods, unless the sump has a lid that makes it a closed container. The idea is to contain
the condensate in a small dedicated container instead of having it slosh around in the bilge. Had this on a previous
boat.....it gets the job done.
2. Install a condensator. Again, these are purchased in kit form. Essentially, a venturi fitting is spiced into the overboard
cooling water drain line from the AC unit. The condensate drain line plugs into the venturi. As cooling water is pumped
thru the venturi fitting it creates negative pressure and the condensate is sucked into the drain line and out with the
cooling water. I have had one on my boat for over 5 years and it works great; bilge is bone dry. Relatively inexpensive
and easy to install with no electrical wiring necessary and no additional holes in the hull.

Note that you should already have a bilge pump and float installed; however, you really don't want to rely on that arrangement to handle the condensate because you will always have a wet bilge when the AC is running. Its really amazing how much condensate is generated during hot humid summers when the AC runs a lot. Much better to get rid of the condensate and not allow it into the bilge. BTW, on my Beneteau, only the float switch is located in a sump in the bilge; the actual pump is located at a remote location under the lavatory in the head. The goal should be to keep the bilge absolutely dry. If it is normally dry and you find water in the bilge, you then know that something is amiss and needs correction.

 

[Ed Caldwell]

The cheaper float switches are easy to install, but notoriously short lived (a couple of years seems to be the max). However, this style switch:
https://www.amazon.com/Smart-Bilge-Pump-Switch-Ss209/dp/B002MDHLS2
seems to work better and last longer. This type is available from a couple of manufacturers (eg Ultra Safety Switch), but cost 3x as much as the Rule type switch.

You may want to see where your shower drain goes, as you may be able to route the AC condensate to that system, assuming it has a built in float switch to turn it on when needed.

On our Hunter, the factory ran the refrigerator drain, shower drain, and AC drain all to the bilge so our bilge pump got a workout! A year ago I upgraded to this:
https://forums.sailboatowners.com/index.php?threads/h340-grey-water-management.186525/
which has worked well so far, although it is noisy when the pump is pumping. I close thru hulls when I leave the boat for more than a day, so I don't leave the AC running.

 

[Peggie Hall HeadMistress]

You don't want anything draining into the bilge...wet bilges quickly turn into primordial soups especially in hot weather..even faster if it's shower water. Route the AC condensate and icebox/fridge drain to the shower sump. If it's too far away, install another sump. A bit of an expensive and bit more of a PITA to do, but definitely worth the effort.

 

[Benny17441]

Oh, water in the bilge? That is what the bilge enclosure was designed for, to collect incidental water that gets inside the hull. An A/C unit removes humidity from the air inside the boat as part of the cooling process but if that water is allowed to remain inside the boat It partially defeats the purpose as it will readily evaporate back into the dry air. The water that gets really stinky is number of gallons of water trapped in the hull stringer below the sole of the average sailboat. There is nothing wrong with directing the A/C condensate to the bilge but it will operate more efficiently if an automatic bilge pump would remove excess water at frequent intervals. Installing a float switch is rather easy. Choose a location along the centerline with the foot pointing aft, make sure the foot has uninterrupted travel at that location. Cut the (+) wire supplying power to the pump and attach the float switch leads to each end of the pump wire. Just leave the 12V main breaker ON and the bilge pump switch and you are good to go. There are more fancy installations where the pump is hard wired to the batteries enabling the 12V main switch to be turned off and there are some dedicated switches which allow both the pump to be operated on automatic or manual. The pump does not have to be very large as its purpose is to remove incidental water and not really constitute a safety pump. To provide safety you would need a much larger pump possibly powered by 120V a/c current. When onboard a manual gusher pump is what we usually rely on. One word of warning, float switches have an earned reputation of frequent failures; they can fail to turn a pump On or can kill the batteries when they fail to turn the pump Off. Frequent checks are recommended. The A/C unit of a boat is a rather expensive piece of equipment that you would probably like to make it last by running it frequently but not continuously. To remove humidity out of the boat we use a 120V home type dehumidifier with the condensation hose going straight into the bilge. When the boat is at the dock we run the unit 24/7 with the control switch at 50% humidity and it does a good job. Very dry air is also not good for certain fabrics and foam rubber so 50% is adequate. The unit can be ran to death and replaced for a lot cheaper than the boat's A/C.

 

[Benny17441]

I can't understand why someone would go through a lot of work and expense to keep a bilge dry. I may clean out my bilge once a year but it always holds about 1 inch of water that the pump cannot remove. I could perhaps understand if you sail in fresh water but at the sea the bilge smell blends with the other marine smells and that is partly why I come out to the boat. If I wanted an anti-septic smell I would go to a Hospital. The thing is everything has a peculiar smell but we just feel those that we infrequently encounter. It has been my experience that if you get on your boat away from land for at least three days you will no longer feel any boat smell but you will feel the stink of land when you return. hey that is just me, so whatever floats your boat is OK.

 

[Davidasailor26]

Our boat came with a small dedicated AC condensate pump with an electronic sensor to activate it. Works pretty well although the sensor seems to get a little flakey sometimes. Our previous boat had the Venturi setup which seemed very reliable, but care must be taken during installation to make sure the valves are in the right place and the plumbing is at the right height.

I'm with Peggy that a dry bilge is a worthwhile goal especially on a boat with a deck stepped mast. A bilge pump isn't usually designed to get every last drop out so I think a dedicated solution for the AC is the better alternative.

 

[BigEasy]

David,
Couldn't agree more with Peggy & you. Why waste efforts & money trying to remove condensate & grey water from the bilge, when its so much easier & cost effective to eliminate it from going into the bilge in the first place.

 

[HanBan]

Hannah,
Sounds like whoever installed your AC ducted the condensate drain into the bilge....not good. Wet bilges will cause odors and there is speculation that wet bilges may facilitate formation of osmotic blistering on the hull because the hull gets water saturation from outside the hull (for obvious reasons) and from inside the hull with wet bilges present.
There are two quick fixes that I am aware of that will keep the bilge dry.
1. Install a dedicated shower type sump in the bilge. These can be purchased from the major chandleries for about $100.
Its simply a small container with a bilge pump and float installed. Duct the condensate drain line into the sump and
another line overboard. Also need to install an anti siphon loop to prevent water from draining back into the sump
when heeled over for long periods, unless the sump has a lid that makes it a closed container. The idea is to contain
the condensate in a small dedicated container instead of having it slosh around in the bilge. Had this on a previous
boat.....it gets the job done.
2. Install a condensator. Again, these are purchased in kit form. Essentially, a venturi fitting is spiced into the overboard
cooling water drain line from the AC unit. The condensate drain line plugs into the venturi. As cooling water is pumped
thru the venturi fitting it creates negative pressure and the condensate is sucked into the drain line and out with the
cooling water. I have had one on my boat for over 5 years and it works great; bilge is bone dry. Relatively inexpensive
and easy to install with no electrical wiring necessary and no additional holes in the hull.

Note that you should already have a bilge pump and float installed; however, you really don't want to rely on that arrangement to handle the condensate because you will always have a wet bilge when the AC is running. Its really amazing how much condensate is generated during hot humid summers when the AC runs a lot. Much better to get rid of the condensate and not allow it into the bilge. BTW, on my Beneteau, only the float switch is located in a sump in the bilge; the actual pump is located at a remote location under the lavatory in the head. The goal should be to keep the bilge absolutely dry. If it is normally dry and you find water in the bilge, you then know that something is amiss and needs correction.

Hi BigEasy,
Wow, there's a lot here, and thank you for the advice.
1 - I'm not really sure what it is you are describing here. For the life of me I can't image in my mind what it is you are trying to explain.
2 - Venturi?! Oh my, this is something I do understand. Fluid dynamics is a fascinating subject (to me), and a venturi would indeed work well, though I hadn't thought about using one for this application. Normally you see them in things like carburetors. I'll need to look into this.
3 - You mention that it causes a smell. Funny you should mention this; I've been trying to track down a stench for a while, and it's been so frustrating trying to find it. However, when I finally emptied out the bilge yesterday (and each bilge had run into the main cabin bilge), there was a noticeable LACK of smell. It occurred to me at that time that the smell might be in the water tracks between bilges.
4 - There is a bilge pump in the boat right now, but it's located behind the starboard settee and the hose runs into the main cabin bilge. I've also noticed that the wood which all the stuff like battery charger and AC are sitting on is a little squishy - now I know why.
Hannah

 

[HanBan]

The cheaper float switches are easy to install, but notoriously short lived (a couple of years seems to be the max). However, this style switch:
https://www.amazon.com/Smart-Bilge-Pump-Switch-Ss209/dp/B002MDHLS2
seems to work better and last longer. This type is available from a couple of manufacturers (eg Ultra Safety Switch), but cost 3x as much as the Rule type switch.

You may want to see where your shower drain goes, as you may be able to route the AC condensate to that system, assuming it has a built in float switch to turn it on when needed.

On our Hunter, the factory ran the refrigerator drain, shower drain, and AC drain all to the bilge so our bilge pump got a workout! A year ago I upgraded to this:
https://forums.sailboatowners.com/index.php?threads/h340-grey-water-management.186525/
which has worked well so far, although it is noisy when the pump is pumping. I close thru hulls when I leave the boat for more than a day, so I don't leave the AC running.

Thanks for the links Ed, I'll have to order one of those.

 

[HanBan]

You don't want anything draining into the bilge...wet bilges quickly turn into primordial soups especially in hot weather..even faster if it's shower water. Route the AC condensate and icebox/fridge drain to the shower sump. If it's too far away, install another sump. A bit of an expensive and bit more of a PITA to do, but definitely worth the effort.

Peggie,
Yes, this was a bit of a shock when I came aboard yesterday. I think we've located the stench. When I was wiping all the bilges, they were very slimy. When I get some time, I may actually fill them all up with some eco friendly cleaning fluid and run them all through.
The boat is going to have all of her rigging done in a week or so, and I'll ask the marina if they can do something to manage the AC runoff.
Thank you!
Hannah

 

[HanBan]

Oh, water in the bilge? That is what the bilge enclosure was designed for, to collect incidental water that gets inside the hull. An A/C unit removes humidity from the air inside the boat as part of the cooling process but if that water is allowed to remain inside the boat It partially defeats the purpose as it will readily evaporate back into the dry air. The water that gets really stinky is number of gallons of water trapped in the hull stringer below the sole of the average sailboat. There is nothing wrong with directing the A/C condensate to the bilge but it will operate more efficiently if an automatic bilge pump would remove excess water at frequent intervals. Installing a float switch is rather easy. Choose a location along the centerline with the foot pointing aft, make sure the foot has uninterrupted travel at that location. Cut the (+) wire supplying power to the pump and attach the float switch leads to each end of the pump wire. Just leave the 12V main breaker ON and the bilge pump switch and you are good to go. There are more fancy installations where the pump is hard wired to the batteries enabling the 12V main switch to be turned off and there are some dedicated switches which allow both the pump to be operated on automatic or manual. The pump does not have to be very large as its purpose is to remove incidental water and not really constitute a safety pump. To provide safety you would need a much larger pump possibly powered by 120V a/c current. When onboard a manual gusher pump is what we usually rely on. One word of warning, float switches have an earned reputation of frequent failures; they can fail to turn a pump On or can kill the batteries when they fail to turn the pump Off. Frequent checks are recommended. The A/C unit of a boat is a rather expensive piece of equipment that you would probably like to make it last by running it frequently but not continuously. To remove humidity out of the boat we use a 120V home type dehumidifier with the condensation hose going straight into the bilge. When the boat is at the dock we run the unit 24/7 with the control switch at 50% humidity and it does a good job. Very dry air is also not good for certain fabrics and foam rubber so 50% is adequate. The unit can be ran to death and replaced for a lot cheaper than the boat's A/C.

Thank you for the explanation Benny!

 

[HanBan]

Our boat came with a small dedicated AC condensate pump with an electronic sensor to activate it. Works pretty well although the sensor seems to get a little flakey sometimes. Our previous boat had the Venturi setup which seemed very reliable, but care must be taken during installation to make sure the valves are in the right place and the plumbing is at the right height.

I'm with Peggy that a dry bilge is a worthwhile goal especially on a boat with a deck stepped mast. A bilge pump isn't usually designed to get every last drop out so I think a dedicated solution for the AC is the better alternative.

Yes David, Peggy and BigEasy have hit the nail on the head. Where I was trying to manage the issue, their suggestions eliminate the problem (much smarter people than me). The boat is off to the marina next week for some work, so I'll have them sort it out.
Hannah

 

[Apex]

Run the AC drain to your sink, that drains overboard, no problem. Peggy has a book for sale, check this site for eliminating boat odors......worthwhile. Clean the boat and work to keep it dry through ventilation and fixing sources of unintentional water..

 

[BigEasy]

Hi BigEasy,
Wow, there's a lot here, and thank you for the advice.
1 - I'm not really sure what it is you are describing here. For the life of me I can't image in my mind what it is you are trying to explain.

Sorry that my description was not descriptive! These shower sumps are self contained small units with a bilge pump & float switch inside the sump. Condensate, shower water, ice box water, etc., drains into the sump and the pump discharges it overboard. I will try to post a photo. The unit is fairly small appx. 12"x 12". If the only water draining into the bilge is from the AC condensate, the condensator (venturi) would be a better option.

 

[Davidasailor26]

Run the AC drain to your sink, that drains overboard, no problem. Peggy has a book for sale, check this site for eliminating boat odors......worthwhile. Clean the boat and work to keep it dry through ventilation and fixing sources of unintentional water..

Good simple solution if it works for you, but offhand I can think of two potential issues for most setups: 1) you then need to keep the sink seacock open, which exposes the boat to more chances of a failed hose causing damage, and 2) the AC condensate collects in an open drain pan, and there's probably no way to get water from that pan uphill to a sink without a pump, which defeats the purpose.

 

[BigEasy]

Run the AC drain to your sink, that drains overboard

This works well if you have enough elevation from the AC to the sink drain. My AC system is split, I use the condensator in the V berth where the AC is mounted on the floor under the berth. In my aft berth, there is a separate air handler that is mounted high in the lazerette. On the aft air handler, I ran the condensate line to the sink drain where I installed a "T" fitting to couple it to the condensate line. Works good and its inexpensive.

 

[HanBan]

View attachment 153387
Sorry that my description was not descriptive! These shower sumps are self contained small units with a bilge pump & float switch inside the sump. Condensate, shower water, ice box water, etc., drains into the sump and the pump discharges it overboard. I will try to post a photo. The unit is fairly small appx. 12"x 12". If the only water draining into the bilge is from the AC condensate, the condensator (venturi) would be a better option.

OHhhh, this makes sense. Thanks.

 

[HanBan]

Run the AC drain to your sink, that drains overboard, no problem. Peggy has a book for sale, check this site for eliminating boat odors......worthwhile. Clean the boat and work to keep it dry through ventilation and fixing sources of unintentional water..

Hi Apex,
I have Peggie's book on Kindle - fantastic read. Unfortunately I've been very busy with Uni lately and unable to find the time to narrow down the source of the smell.
Han

 

[Peggie Hall HeadMistress]

When I was wiping all the bilges, they were very slimy. When I get some time, I may actually fill them all up with some eco friendly cleaning fluid and run them all through.

Is that all you'd do to clean a slimy stinky container at home and expect it to be clean? Cleaning a bilge requires some manual labor. The best tool is a power washer 'cuz it can get water and detergent into places you can't reach by hand. Scrub with plenty of detergent (forget bleach!) and then THOROUGHLY flush ALL the dirty soapy water out.

There's a whole chapter in my book devoted to bilge cleaning and why a clean bilge is so important. See link in my signature.

--Peggie
"If you can't explain it to a six year old, you don't completely understand it yourself." --Albert Einstein
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