We prefer a dry bilge
The job which prompted yesterday’s visit to Compass Point Marina was the installation of our brand new salon air-conditioning unit. The new 16000 BTU Cruise Air system is a direct replacement for the older unit which stopped functioning. Why did it stop working?
At some point early in the year, the salon AC unit developed a refrigerant leak. Each hull has its own separate AC unit and with those running, the guests’ cabins were kept plenty cool. We seldom find it necessary to run the salon unit so we just decided to not worry about it. When we ultimately decided to go ahead and get it fixed, we found that the compressor had seized up, presumably from non-use. This once again reinforces the rule that things that need to move must be kept moving! Anyway, Rebecca and I removed the old unit yesterday and the boys from Reefco installed the new one. A few boat bucks later and the salon is once again super cool.
While they were on board, I queried Reefco’s owner Dave about a solution to my biggest pet peeve about the Leopard 4600. The way it is designed, and I understand many other boats are set up the same way, the condensation from the air conditioning units simply drains into the bilge. It’s not a lot of water but it is enough. Unfortunately, the bilge pumps don’t remove it until it really builds up. Rebecca and I much prefer ZTC’s dry bilges and thus are looking for a solution.
The solution that Dave suggested was the Mermaid Condensator. Supposedly by using the Venturi effect, this device allows the AC unit’s condensation to be drained through the actual discharge line. It can be purchased for approx. $160.00 US each and to achieve our goal of having a dry bilge, we would need three of them. That’s one solution.
A second option is to have the condensation drain into a sump box, similar to this one. The water is kept contained in the small box until it is pumped overboard by the enclosed pump. The way I see it, we could get away with only two of these. This would have the added benefit of allowing me to run the refrigerator drainage into the box.
Decisions, decisions. Anyone had to cross this bridge before?
I like the condensation box. We have one in our downstairs AC unit and it works flawlessly, knocking on wood..
That is what we decided to do. We have two on order already.
I use an Arid Bilge pump, it will keep two zones bone dry.
Check out their web site.
I’m compulsive about keeping my bilge dry, and this thing works. It’s a bit expensive, but it will work to keep your bilges dry from all sources of water, not just the ac.
I’ve followed your blog for a couple of years, thanks.
That looks cool, although much more complicated. I never even got to the price. 🙂
Mike, our Lagoon 43 PowerCat had 5ACs draining into the bilges :(. I installed whale grey water tanks (http://www.whalepumps.com/marine/product.aspx?Category_ID=10023&Product_ID=10038&FriendlyID=Grey-waste-tanks) which are sealed and have built in float switches. I then use Whale Gulper pumps to empty them as needed … quiet and dry.
I also plumbed (since it was close) my shower drains to these … now the showers are “automatic” emptying and I got to reuse the pumps (the whale gulper was the shower sump).
Good solution.
Mike,
Our AC condenser drains into the Rule box and then gets pumped overboard. Other “periodic” drains like the drain on the floor infront of the forward head sink also drain into this box. Keeps the bilge dry and prevents mold, which happens from the air conditioner condensation if you don’t clean it regularly.
Only issue with the rule box is the float switches go bad regularly. Buy a couple and you should be good.
Bob
Thanks, Bob.
In our own quest for the proverbial dusty bilge, we plumbed our AC condensate drains to the same gray water sump that also receives the effluent from the showers and below-decks sinks (the upstairs ones go directly overboard.
If you already have sumps for the showers you can probably do the same, otherwise I would favor adding the additional sump for the condensate. If the evaporator for the salon unit is above the waterline, you might also be able to just run it overboard. It only requires a very small tube, perhaps 5/16″.
The Arid Bilge system is great, right up until you price it…
Each shower has its own sump in the floor area and the water collected there is manually pumped overboard by activating an on/off switch in the shower (Four showers, four sump areas, four pumps). It would not really serve to have the condensation drain there as it is not automatic. Two of the three AC units are below the water line.
We’ve always drained ours directly overboard through an above waterline thru hull. Nothing mechanical or electrical to break.
Unfortunately 2 of the 3 are below the waterline.
our aft shower, plus aft a/c, plus salon a/c, plus RO drain all dump into our aft sump box, and are then pumped over like your example. Where does your shower drain?
As I just typed in response to a different comment, each shower has its own sump in the floor area and the water collected there is manually pumped overboard by activating an on/off switch in the shower (Four showers, four sump areas, four pumps).
Mike,
We have that EXACT same box in your picture on Journey to drain shower water. It is a nightmare I’ve been dealing with for 2 years. It gets very smelly and clogs and leaks. That said, its soapy shower water, not clean condensate and you have a boat that dosn’t heal. Still, I would vote for the Whale Gulper mentioned in the comments above.
Yes, shower water can get very nasty!
I have read about the contesters but think that I would go with the box. In an emergency you could gain another pump by removing cover
Right.
We have the Mermaid Condensator on September Song. It works great. I do not have a dry bilge due to having a conventional shaft packing, but the AC does not add to the water at all. When the AC is running, if you put your head in the compartment with the unit, you can actually hear the condensator pulling the water out of the drip tray.
If you were going to install the sump box, how many of them would you need? I am guessing two, since there’s probably not a downhill path from all three units to one place on your catamaran. How much for the complete setup to install two sump boxes versus three Mermaid Condensators? And would you need to drill more holes in your hull to add the sump boxes? Just some things to consider…
Two boxes as opposed to 3 condensators. The price different is noticeable.
There’s also the added complexity and more electrical connections, moving parts to break, etc…
True. I have friends who both have the condensator installed, and installed them for a living, who told me NOT to use that. There must then be downsides to it, right? Getting clogged?
You could try using a condensate pump used for Hi efficiency nat gas boilers. They have their own float, 1-2 qt reservoir, small pump and can be had for $40 or so at Home Depot , Lowes etc. They do run on 120 AC however, but there may be some that are DC
The 120V might not be that much of an issue as the Air Conditioning units run on AC (alternating current for clarity) power, not DC.
Probably a little late…but my Leopard came with the Mermaid condensators installed on both of our AC units. So far, it has worked just fine…more than I can say for the raw water pumps.
-Mike B
http://ThisRatSailed.blogspot.com
The pumps for the AC units?
Yeah, the 110v March pumps that supply water to the main salon AC unit. I think I need to replace the impeller or pump head on one…I can hear the motor spin but no water cycles.
They are mounted in about the least accessible place on the boat so I have been procrastinating on the investigation…I can live without AC (or in my case heat)…at least until this arctic blast they are predicting arrives. Non-critical system puts it down on the list of priorities. 😉
I hear you. We just ended up replacing our salon AC though due, in part, to non use. Something to consider when the to-do list gets smaller.