condensation

[suse]

Not surprisingly at this time of year, we have some condensation, mainly in the aft cabin, running down the sides, which are lined with foam-backed plastic headlining (ugh!). When sleeping in this cabin, we and our bedding lie against the sides, and consequently get damp, unless we take great care. Being a sissy, I have a feather/down quilt, which I would prefer to stay dry. Any suggestions concerning eliminating condensation? There is also some in an open locker in this cabin, which has no insulation and is built directly against the hull, so we cant use this - a minor nuisance.

Thanks in advance.

susy

<hr width=100% size=1>

 

[AndrewB]

If you have access to power, then a dehumidifier will work wonders. A cheap one from Argos costs just under £100. Expensive marine ones are less bulky, but work no better. Condensation type, NOT chemicals, you need something capable of pulling ½ gallon or more out per day.

However, if you are living aboard, then with that little insulation in your sleeping cabin, problems are inevitable. My present yacht has 2-3" of insulation throughout down to the waterline and although I didn't buy it for that reason has proved a godsend for winter liveaboarding and sailing. There is absolutely no problem except around the windows. With previous yachts I just used to abandon the ends in winter.

"Thistleskipper" who sometimes posts here, is over-wintering aboard in Maine and posted that local liveaboards shrinkwrap the top half of their boats, which initially she was saying worked well. Don't know whether it has continued to prove effective though.

 

[bedouin]

Do you mean when you are on board, or when the boat is left?

Either way, the easiest answer is ventilation.

<hr width=100% size=1>

 

[tcm]

Yes, the answer to condensation is insulation, dehumidifier, heating and (then) ventilation - though massive ventilation isn't vital with good insulation and dehum. Lots of ideas have been through here from cork tiles through to sound insulation pads.

I wouldn't think the shrinkwrapping is a great idea, though it must depend on moisture levels in the air.

Soudn a bit of a rum do to be sleeping in there with water dripping down the sides - even the tiniest opening of a hatch will stop breath condensing in this way.






<hr width=100% size=1>

 

[mtb]

uuurrr dont seal it up , Danbrit was shut up, it realy causes so many problems.
A posh solar vent would help.

mick


<hr width=100% size=1>smile you'l be on your boat soon ;-)
<A target="_blank" HREF=http://homepage.ntlworld.com/boats/>http://homepage.ntlworld.com/boats/</A>

 

[charles_reed]

The answer is easy>

Insulation
Ventilation.

But difficult to practice.

I ensure a through draft in the boat (in nature it's from main hatch to forehatch) and find a fan heater works wonders (far better than any de-humidifier).

Having lived on the boat when it's -8C outside, I doubt you'll ever banish condensation, but if you air the bedding (even hung up in the cabin does) every day you'll keep the worst at bay.

<hr width=100% size=1>

 

[AndrewB]

Is good ventilation really that effective?

At controlling condensation, that is.

Everyone says so ... but is the result of personal experience or just echoing an opinion?

Some years I've closed the boat right up, others its been well ventilated. Can't say I've noticed any real difference.

To stop condensation, what has to be managed is avoiding a steep temperature gradient, with moist air on the warm side. Ventilation will only be effective if it really thoroughly keeps the inside of the boat cool, and the humidity low on the inside. If you are sleeping aboard particularly, giving off both heat and moisture, that implies a LOT of air circulation. Many years ago when I lived aboard on a damp GRP boat through winter, I did control condensation in the main cabin by leaving the main hatch completely open and the foredeck hatch ajar at night. Might as well have slept on deck. Boat kept condensation free and I got really hardy. Definitely not something I'd do now!

<hr width=100% size=1>

 

[[2574]]

Yes, I always reckon on dehumidifier, which runs on my boat from November to March. It has solved all condensation/dampness problems. What I've never managed to understand though is having a dehumidifier AND ventilation. Surely if you thoroughly ventilate a boat with a dehumidifier running, the machine is trying to dehumidify the whole of Hampshire! So, I don't have any additional ventilation provision alongside our dehumidifier. I do deploy bar heaters to keep the air warmish - the theory being that warm air carries most mositure to the dehumidifier for extraction.

<hr width=100% size=1>

 

[Iota]

As well as a dehumidifyer a green house heater to help the keep an even temperature helps. If no shore power harder. There are some furry type materials you can buy to line the side of the cabin by your berth, they help but do not eliminate the problem, same with some coir type material underneath the cushions. no easy solution though.

<hr width=100% size=1>Courtesy is an iota but makes the world go round

 

[heerenleed]

We live aboard in the Netherlands. Probably worse than Maine or any other very cold area, where it may be cold, but at least the relative humidity of the air is very low. Here is isn't very cold most of the time, but, especially at the beginning or at the end of winter it may get very damp.

When we installed the heating system, we have chosen a double system. We have a water heating system with convectors/radiators, but, on top of that we have a large heat exchanger in the engine room which heats air from outside the boat and blows it into the different cabins we have.

Apart from that we have done a large insulation job, using rubber carpet underlay over a layer of this wrapping material (don't know the name in English but it is a plastic sheet with air enclosures) underneath against the hull.

Never ever have problems with condensation. In our marina there are some 15 boats inhabited. All agree that there is no such thing as battle against the cold, but there definitely is a battle against condensation.

If you want to know exactly how this was done, please have a look at my earlier postings about heating a boat.

happy sailing (winter's almost over)



<hr width=100% size=1>Peter a/b SV Heerenleed, Steenbergen, Netherlands

 

[charles_reed]

Re: Is good ventilation really that effective?

Sorry I can only speak from experience.

Ventilation is probably the most effective way of reducing condensation in my book - the trouble is that it's very difficult to ensure in the bunk cushion/base interface.

I just accept it's going to happen and air the bunk daily.

I spend about 8 of 12 months on my boat, including winter weather.

But I do love an honest sceptic.

<hr width=100% size=1>

 

[bedouin]

Re: Is good ventilation really that effective?

I have had to deal with condensation in a number of areas, including boats and houses, but I wouldn't call myself an expert.

In an unheated, unoccupied situation ventilation works well provided that there is a good airflow throughout the space, areas of dead air will still cause condensation. Even better is sealing the space as tightly as possible and using a dehumidifier - but I'm not sure that's necessary on a boat, even if you do have access to mains power.

On an occupied boat I have found that a combination of good insulation and ventilation minimises condensation - but does mean one can get a bit chilly at night so wrap up warm. I haven't tried using a dehumidifier in those conditions, so I can't comment on whether that would be effective, but I would imagine so.

In any occupied space, people generate water - I can't remember the figure but it is something like a couple of litres a day (maybe less on the boat). The only two ways of getting rid of the water is either by using a dehumidifier, or by ventilation - more specifically letting warm, saturated air out and bringing drier, colder air in (I have bought a unit for my house that includes a heat exchanger to reduce the energy loss caused by this process, but it's not installed yet).

When I had a blown-air diesel heater on my boat, that pulled it's air from outside the cabin, that was excellent at drying the boat, but somewhat expensive to run as a long term option.


<hr width=100% size=1>

 

[timevans2000]

I stay onboard most weekends in the winter and every weekend in the summer. I have 3 large dorades that I rotate to either suck or blow dependant on wind direction. I always leave the bedding on the boat and it is always dry. I have a 5kw drip feed diesel heater that combined with the excellent ventilation ensures minimal condensation. Also cabins are well insulated. The only cabin that is damp is the one we use for storage. It has no decent insulation, no heating and no dorade. It is open to the saloon but this is not enough to keep it damp free.
This weekend we are stripping all the existing lining off to fully insulate.

We dont use a de humidifier as in the winter they tend to freeze up unless you have a heater running. I found in the past it was cheaper and far more effective to create through ventilation

<hr width=100% size=1>