Condensation And Smell Under Mattress

[SV__Grace]

Need air circulation under there and your slats are probably blocking that.

As liveaboards this was an important problem to solve for our queen size aft cabin mattress, and spent $100. at a boat show to get something like this-
HyperVent Marine - Putting An End To Condensation

I can't remember the brand name of ours, but it seems very similar to the above and works well.

Even then, during conditions that create lots of condensation, it's best to air out that area every other week or so as a maintenance task, and if leaving the boat for an extended period (month or more) to flip all your cushions up to let air circulate.

Froli looks great too.

[Dougtiff]

No matter what you use, if you isolate the mattress, i.e, when making the bed, the cover drapes over the bed, there will be no circulation, you need to not drape over.

[jump12k]

Under what the last post suggested... I drills a bunch of 1/2” holes for air flow... been dry since

[gonesail]

if your boat is warmer than 60 degrees I recommend a dehumidifier to get the humidity below 50% .. even your breath is a problem in the confined space of a boat.

[Mike Banks]

here is only one permanent way to stop this and that is to ventilate the area under your mattress. In my case I used one of those computer fans mounted inboard against the hull and drawing air from beneath the mattress, and on the far end in a similar position was a series of holes drilled in the bunk sides just at the sides of the the frame holding the under-mattress. You put the fan at your feet end of the bunk--the inlet holes at the head end and if you are like me you put some insect mesh over them to stop any critters colonizing the under-mattress space. Any small low-power fan will do--it was just that the computer fans are very cheap, small, quiet and efficient.

[guyrj33]

Insulate, ventilate and dehumidify.
Insulate to move the condensation point into the middle of some closed cell foam.
Ventilate to distribute moisture evenly.
Dehumidify to dry air and reduce potential for condensation.

[scarlet]

Originally Posted by guyrj33

Are the slats removable, could you add some closed cell foam insulation under them?
Or perhaps you could insulate the underside of the berth area?
Something to move the condensation point away from the area under your mattress.

I'm definitely thinking of adding something like this... it has been really cold, and so I've been using an electric blanket at night... so, that may be adding to the problem. This boat is so poorly insulated. obviously a boat for the Caribbean, which is great.. but I've been looking for ways to add insulation... so perhaps this would be a solution..

[JPA Cate]

Originally Posted by scarlet

I'm definitely thinking of adding something like this... it has been really cold, and so I've been using an electric blanket at night... so, that may be adding to the problem. This boat is so poorly insulated. obviously a boat for the Caribbean, which is great.. but I've been looking for ways to add insulation... so perhaps this would be a solution..

1/4" closed cell foam will make a huge difference. If 1/2" is cheaper, you can still work with it, and make a world of difference.

Ann

[Aircool]

We also have hypervent and its a wonder

[ggray]

Insulation has been mentioned, but I think what was suggested was insulation under the mattress.

If might be more effective, although more difficult, to insulate the hull under the mattress with soft closed cell foam. At least where it can be done. Seal the edges (with tape so all can be removed and cleaned seasonally if necessary) to limit air getting underneath.

Not speaking from experience, but I would try this.

[Cheechako]

Find a say to circulate air through the slats. Holes in the plywood berth tops, computer fan in the cabinet to push or draw air through...

[Tayana42]

Another good experience with hypervent. Installed it 15 years ago and it did the trick for us. Not cheep but it works and it is easy enough to cut to shape and install. Not had any condensation issues under the mattress since. Lived aboard for 3 years.

[Canarios]

Even if you use HyperVent and ventilation under the bunks, you have very high humidity in the boat. The mattress, especially the foam rubber mattress, and bedding are filled with moist air. Remember that, by breathing, you emit a lot of moisture and at night the body itself emits a lot of moisture that is absorbed by fabrics etc. It also condenses on cold surfaces and becomes water. at higher humidity levels in the air there will be more condensation water. The only way to reduce humidity is to use air dehumidifier.

[Zanshin]

Canarios - I disagree with your statement about a dehumidifier being a requirement to reduce humidity. I suspect that the 99% of boats that don't have a (power hungry) dehumidifier aboard would agree with me.

The way to reduce the humidity is to ventilate - that brings the humidity below the mattress down to ambient humidity.

[Salmonater]

Our cruising area is Washington to Alaska so we are very familiar with condensation issues in sleeping cabins. In our main cabin we tied a Goldenrod dehumidifier in the coils of the innerspring mattress. In cold weather, we plug in an hour before bed and unplug the next morning. Makes for a cozy / dry mattress. Goldenrod consumes 1w/inch; a 12” rod uses 12w/hr. Also, crack the overhead hatch and cabin door to encourage flow-through ventilation to expel moisture.