Page 1 of 2 12 LastLast
Results 1 to 20 of 30

Thread: Cabin condensation

  1. #1
    Member HuntKodiak's Avatar
    Join Date
    Feb 2007
    Location
    Kodiak
    Posts
    684

    Default Cabin condensation

    Would like some ideas on how to best reduce/eliminate condensation build-up in the my boat's cabin after a night of sleeping. As you can imagine, living on Kodiak comes with rain occasionally, and when that happens, I can't leave a window cracked.

    With 3 sleeping inside, the windows are completely fogged over by morning, and I can feel a dampness in the air. I don't leave the heater running because it would be too warm, burn un-needed fuel, and drain the batteries faster. I'm thinking that adding a small covered vent or two on the aft bulkhead towards the top of the ceiling. I also think it would be nice to close the vents when I'm not concerned about condensation building.

    I know this isn't an usual problem, but I haven't read too many of you talk about solutions. Would love to see pictures of solutions to help me visualize what you did.

    Thanks!

  2. #2
    Member spoiled one's Avatar
    Join Date
    Apr 2006
    Location
    Anchorage
    Posts
    3,230

    Default

    My espar runs 24-7 when it is raining or cool outside. I just turn the thermostat down and crack a window while we sleep. It really cuts down on the moisture in the air. Personally, I would just run the heater. If the batteries get drawn down too much, you might consider a beefier house bank. Life is too short to rough it, man.
    Spending my kids' inheritance with them, one adventure at a time.

  3. #3

    Default

    Need 2 things to solve it. Ventilation, I have a 12v nicro vent fan in the cuddy hatch that exhausts air and removes the condensation from the cabin. And heat, the heat needs to have the exhaust vented outside like wallas, espar, toyo, etc., that way it dries the air and does not add condensation from the combustion like non vented heaters. Only way i know of solving it. I also use fans inside to help circulate the air around cabin. These solutions run fine on a single house battery that you can charge when you are running.

  4. #4
    Member HuntKodiak's Avatar
    Join Date
    Feb 2007
    Location
    Kodiak
    Posts
    684

    Default

    Well geez Spoiled One, now you're trying to make me soft! Run the heater all the time?! Right now I run on one of two batteries while anchored. The heater is hard-wired (fused and switched) to one battery, and I throw my bank switch to run lights & electronics off the same battery, which leaves me a fully charged battery waiting. One battery lasts 5 days without running the motor for a recharge. My guess is if I run the heater all night, that might cut my battery time in half.....just a guess though.

    My Wallas install actually doesn't have a thermostat. It has a high/low toggle switch for heat setting, but I have read that I could install an optional thermostat. Maybe that's a good option, but I'd still need a place for the moist warm air to exit. Cracking a window (mine are sliders like on most boats) would allow rain to enter, which would defeat the purpose of opening the window.

    Are your windows covered some how?

    On a Spring hunt when this was a real problem, I had thoughts of something like a vent shade like you see over truck windows, but I didn't like that idea for a few reasons. That's why I'm thinking about installing a small vent or two.

    Thanks.

  5. #5
    Member spoiled one's Avatar
    Join Date
    Apr 2006
    Location
    Anchorage
    Posts
    3,230

    Default

    I have the standard sliding windows that diamond seaglaze sells. I crack the one opposite my exhaust vent about an inch. I don't have rain entering that I can see. Are you getting rain entering or is water running or dripping in from the roof? I do have screens on the sliders that might prevent water from entering. My house bank consists of four 6-volt golf cart batteries and have been happy with them. Remember, to optimize the longevity of your batteries you should not let them drop below 50% or 12.2 volts. Here is an excellent tutorial on batteries: http://www.batterystuff.com/tutorial_battery.html#8

    Refresh my memory. Which wallas heater do you have? I had the 1300 in my old hewescraft and it was either on or off, but never got too warm in the cabin. I thought the bigger wallas heaters were thermostatically controlled. Does it rain Kodiak?
    Spending my kids' inheritance with them, one adventure at a time.

  6. #6
    Member HuntKodiak's Avatar
    Join Date
    Feb 2007
    Location
    Kodiak
    Posts
    684

    Default

    I had never considered adding a separate house bank of batteries. When you say house bank, what do you run off the bank. Obviously, you have your heater and my guess is lighting. Anything else? Do you have this bank on a separate selector switch that's tied into your main selector for charging, or do you have a different setup to select your batteries? I realize this is a little off the original topic, but I do agree with you and C-Dude in that heat will help get rid of the moisture. So, a good solution for heat makes this a good topic to flush out.

    I have the Wallas 2400, and it's ducted to three adjustable registers. One in the cuddy, one in the middle of the dash, and one mid-way back on the stbd side 3" off the deck. Thermostat is an option, but standard is a 3 position toggle. Up is to ignite and runs the heater on high, middle is off, and down is low.

    Rain doesn't drain down onto the window because there is a gutter channel above the window, and I too have screens. Kodiak rain normally comes with some form of propellant that helps keep the rain from falling straight down out of the sky. On anchor the boat normally noses into the wind, but that doesn't eliminate the beam shots and swirling wind that'll blow some rain in the window. And most of all, I'll sleep a lot better if I know an open window isn't there begging for Mother Nature to screw with me. Especially if I'm being a nice guy and sleeping on the deck.

  7. #7
    Member spoiled one's Avatar
    Join Date
    Apr 2006
    Location
    Anchorage
    Posts
    3,230

    Default

    Quote Originally Posted by HuntKodiak View Post
    I had never considered adding a separate house bank of batteries. When you say house bank, what do you run off the bank. Obviously, you have your heater and my guess is lighting. Anything else?
    I have two 12 volt, cranking batteries for starting batteries. One for each F250. I have a switch up at the helm that will isolate the cranking batteries from everything else. Once the motors are shut off, I turn them "off". Everything else operates off the bank of 6-volts that are run in series, parallel. This includes all electronics, heater, stove and oven start up and fans, lights, water pump, etc. I also have an inverter. Have to run the coffee pot and we can buy a lot of time with the kids by letting the kids watch movies. Once I hit 12.2 V I fire up the honda 2000. The cranking batteries are used only for starting each engine.

    I have been whipped around in circles while on anchor and have never had a noticeable amount of rain enter through a cracked window. It does not have to be opened much to allow airflow.
    Spending my kids' inheritance with them, one adventure at a time.

  8. #8
    Member breausaw's Avatar
    Join Date
    Oct 2006
    Location
    Anchorage
    Posts
    830

    Default

    Another option that will cut the condensation way down is insulating the hull. I sprayed 5 gallons of Delta T in my V-birth and cabin ceiling and walls. This alone took care of 80% of the condensation problem and acts and a sound dampener. My Wallas is 2 burner 85DU with blower lid, it doesn’t have thermostat just a control that allows me to turn it way down. My center cabin window tips out so I can open it without letting rain in.

    http://www.mascoat.com/mascoat-marine-insulating-paint.html


    http://www.c-brats.com/viewtopic.php?t=1629

    There are a lot of discussions on the Delta T over on the C-brats site. It’s expensive, about $600 per 5 gal bucket, but worth the investment if you are serious about reducing condensation; it’s also paintable with latex paint. Takes about 3 good coats to do the job and you need an air compressor and a special spray gun like what is used for undercoating.
    Jay
    07 C-Dory 25 Cruiser
    OurPlayground.


  9. #9
    Sponsor potbuilder's Avatar
    Join Date
    Apr 2006
    Location
    Palmer
    Posts
    4,234

    Default

    I made a plexiglass "vent" window to go over one of my sliders on the bowpicker. I cut it out to shape then siliconed some foam insulation on the cabin side for a spacer then siliconed the plexi vent on to the foam. If you look at the picture you can see it on the front of the window above the numbers 27. Worked great for the 20 years i owned the boat, i'd crank up the dickinson diesel stove and everything was dry and warm.
    DEC cordova harbor.jpg

    Alaska Shrimp Pots

    Rigid & Folding Shrimp & Crab Pots
    Electra Dyne Pot Haulers
    Ropes, Buoys, Bait
    alaskashrimppots.com
    akshrimppots@mtaonline.net
    907 775 1692

  10. #10
    Member HuntKodiak's Avatar
    Join Date
    Feb 2007
    Location
    Kodiak
    Posts
    684

    Default

    Steve, Your attached picture didn't make it. Can you try again?

    Thanks,
    Mike

  11. #11
    Sponsor potbuilder's Avatar
    Join Date
    Apr 2006
    Location
    Palmer
    Posts
    4,234

    Default

    i think its on there now. I think a guy could rig up a vent like that with some velcro so it could be taken off when not needed. I used 1-1/2" thick foam so i had lots of space between my cabin window and the vent window.

    Alaska Shrimp Pots

    Rigid & Folding Shrimp & Crab Pots
    Electra Dyne Pot Haulers
    Ropes, Buoys, Bait
    alaskashrimppots.com
    akshrimppots@mtaonline.net
    907 775 1692

  12. #12
    Member fullbush's Avatar
    Join Date
    Feb 2010
    Location
    Wasilla
    Posts
    2,674

    Default

    you need to get a small diesel stove that has a gravity feed tank--It don't need batteries to run. Mine runs 24/7/365
    Heres one version called the Dickinson "Alaskan"






    I'm taking a poll
    <--------click this star if you think I should run for Gov

  13. #13

    Default Nicro

    Product Features:
    • Circulates fresh air in boat cabin eliminating mold, mildew and musty air
    • Moves 1,000 cubic feet of air/hour or 24,000 cubic feet of air/day
    (4” model)
    • Rechargeable battery allows for 24-hour continuous operation
    • Whisper quiet fan operation
    • No wiring required
    • Interchangeable intake and exhaust fans
    • High capacity NiMh battery operates vent for up to 40 hours without
    sunlight on a full charge
    • 2 year limited warranty
    • All mounting hardware, interior trim ring, and insect screen included
    • Direct to deck installation
    • 3” and 4” models are available to fit any deck or hatch installation
    • Built-in on/off fan switch
    • Complete air and green water shut-off from below
    • All Day/Night PLUS models come complete with two fan blades,
    white plastic interior trim ring, insect screen, mounting hardware
    and an easy-to-understand installation manual.
    • Replaces NICRO 3” & 4” snap-in deck plates
    (fits existing holes once snap-in deck plates are removed)

    nicro.png

  14. #14
    Member jrogers's Avatar
    Join Date
    Apr 2006
    Location
    Anchorage
    Posts
    1,539

    Default

    This may be a bad idea, I have not tried it, but what about one of these dehumidifier products?

    http://www.starbrite.com/sproductdetail.cfm?ID=1110

    M
    y boat is very well insulated, and I still have this problem. It is not condensation, but moisture from all of the people on board. People really put out a lot of water when they sleep. Personally, I crack the windows, but I don't have the Kodiak sideways rain problem that the OP does. I set a personal record this summer, sleeping 10 people for two nights on the boat. Talk about some fogged windows in the morning!
    2009 Seawolf 31'
    www.seawolfmarine.com
    Fully Loaded

  15. #15

    Default Black Cat propane heater

    It's about as big as a sunflower, the little green propane bottle screws in the back. We leave the cabin door open, with the Black Cat on the floor. People make the moisture and the heat (two people can heat an igloo to 65 degrees just by themselves...) this just cuts down the moisture a bit. Works well for five people!

  16. #16

    Default

    I read somewhere in a sailing or cruising book on this topic and it mentioned minimizing the amount of wet items in the cabin like wet clothes, towels or cooking with open pots etc. I try and keep wet raingear and towels stored either in the head or in outside storage and boil water in a tea kettle to minimize steam in the cabin. Like everyone else, I still have fogged windows in the morning but it does make a difference on how much heat and time it takes to defog. and lower the humidity by minimizing water sources.

  17. #17

    Default

    My opinions.

    I've used the Starbrite (or similar brand) stuff, but only over the winter when the boat's closed up and tarped. It works, but slowly so I don't think it would help in the short term. Plus it generates a water that will stain metal if spilled (think moving boat). When I winterize, I take a few plastic containers/trays and spread some kitty litter (clay) on it. Some prefer scented but either is fine. Then I put a layer of the Damp Rid (brand name) stuff on top and set it in the cabin and bilge. The Damp Rid stuff absorbs moisture in the air and dissolves making a liquid. The kitty litter absorbs the liquid. Throw it all out in the spring. By the way, the Damp Rid (and Star Brite) stuff is plain old calcium chloride, not to be confused with sodium chloride/rock salt. Commonly used for melting ice but hard to find in the big, cheap bags in Alaska because most the stuff you can buy here is calcium chloride mixed with salt, or just some other chemical alltogether. I've found it somewhere in the big cheap bags one time, but forgot where. If you can't find it in the big cheap bag, DO go to Wal-Mart and buy the big Damp Rid containers. Half gallon, I think. DO NOT buy the stuff in the Wal-Mart fishing/boating aisle. Too expensive. Get it in the cleaning supplies or similar section of the store. NEVER buy it at W. Marine. Stupidly expensive and nothing more than just calciuim chloride.

    Propane heaters in boats - I've always found them to put out gobs of moisture.

    I run a Wallas cooktop with lid blower all night and that's the only think I've found that does the trick for me. Have to crack a window or door even at the lowest setting. Very little drain on the batteries. I have it direct wired to a dual-purpose marine battery.

  18. #18
    Member HuntKodiak's Avatar
    Join Date
    Feb 2007
    Location
    Kodiak
    Posts
    684

    Default

    Good ideas put out there guys. thanks.

    Potbuilder, your solution looks a lot like the vent shade idea I mentioned earlier. It's a vertical mount of a large version of a window shade that you see a lot of trucks sporting so they can crack their windows on a rainy day or hot day without worrying about rain entering. Interesting design.

    Fullbush, my boat isn't big enough nor configured right for a Dickerson. I've seen them in the corner of a cabin on other boats, but I don't have the room. Two bench seats occupy the area in the aft part of the cabin where I've seen these heaters installed before. They do provide a dry heat without draining batteries.

    C-dude, not ignoring you, but needed to check out the nicro. Problem I found was in the reviews. I went to a few web sites, and it was almost even odds for good vs. bad reviews. Most common complaints were the low amount of air flow and high failure rates most commonly attributed to rechargable battery failure. For >$100, I'd expect the thing to work perfectly. Haven't found another model that has the desired features and great reviews.

    Jrogers, I applied the term condensation to all the moisture buildup inside the cabin. Agreed, it's coming from bodies and not so much hot/cold barrier effect. I have no buildup until biologicals enter the cabin breathing. Guess we need to breath less.

    Jrogers and Skydiver, Like you suspected, starbright isn't enough to correct for the moisture problem I'm talking about, and I too have found kitty litter a good help in combating winter storage moisture buildup. After all, isn't that what the stuff is designed to do.....absorb moisture?

    Dreamcatcher, part of the nice thing with the cabin is the ability to dry any clothes and boots that need it. I don't have a separate head. My marine head is built under the stbd bench seat with a curtain to pull around. Honestly, it rarely gets used by guys hunting, but I digress. I have an adaptation for my Wallas so I can feed two pieces of 76mm ducting down into boots so they dry. So I accept moisture is definitely coming from gear, and like some have suggested, I'lll need to run my heater more. I'll find out how much that drains my battery after I do it some.

    Has anyone installed small stainless steel clamshell vent covers high on the outside of the aft cabin bulkhead? This would be a sub for cracking windows, and if installed with the openings pointed down, it might work nicely. I would want to either drill some tiny holes under the clamshell to act like a screen or a larger hole (maybe an inch or so) with a mesh over it to keep out bugs, bees, and wasps. My initial thought is openings up high where moist heat goes would provide a passage for moisture to escape.

  19. #19

    Default

    Calciuim Chloride can be purchased at almost all concrete companys as they use it accelerate drying of concrete.

  20. #20
    Member
    Join Date
    Nov 2006
    Location
    Anchorage
    Posts
    9

    Default

    Quote Originally Posted by HuntKodiak View Post

    I have the Wallas 2400, and it's ducted to three adjustable registers. One in the cuddy, one in the middle of the dash, and one mid-way back on the stbd side 3" off the deck. Thermostat is an option, but standard is a 3 position toggle. Up is to ignite and runs the heater on high, middle is off, and down is low.
    If you're thinking about it, know that a thermostat on a Wallas only toggles it between low and high automatically to raise or lower the heat - it doesn't cut it off.

Page 1 of 2 12 LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •