Cutting down on condensation.. can it be done?

[Nostrodamus]

Condensation appears to be a way of life for boats especially if you are living aboard during colder weather.
Whilst cleaning and removing certain panels there is an air gap to the hull and these seem to be the problem areas.
Have you insulated your boat in any way, can it be insulated and besides a dehumidifier is there any other way to help cut down on the condensation?

 

[uxb]

Covers over the hatches help- we fitted them to our boat ( it's got s fair ammount of glass) and it cut down the condensation a lot.

 

[Seajet]

I fitted polystyrene tiles and silver foil between the headlining & deckhead; seems to help a lot re.condensation ( don't get any there now ) and I like to think it's increased her radar signature ( in a fairly random, 'show up moving about in waves or to search aircraft' sort of way ) but I haven't conducted tests !

 

[clyst]

Depends where the condensation occurs . If its under the matresses -----a very common problem area , its easily solved using matting from the likes of Hawkhouse .

If its general condensation in lockers etc then for livaboards i'm afraid its "dehumidifiers" . We run 2 (1 in aft cabin and 1 in main saloon) all winter and have no problems with damp nor condensation . We dont take extra care to "seal" the cabins but they seem to work a treat.

Another tip . We have fitted extractor fans above the galley and in the heads

 

[Baggy]

Open up your hatches and leave the washboards out..
A bit of cold wont hurt a ruffty tuffty sailor like you...

BTW I did use bubble wrap on the hatches/port windows, with a certain amount of success

 

[Blue5]

is there any other way to help cut down on the condensation?

Breathe less.....

 

[Robin]

Halve the condensation by sending SWMBO to visit her mother?

 

[TopDonkey]

I have found that running a small desk fan on medium speed at the foot of my bed blowing towards my head whlst sleeping makes a massive difference.

I think it stops the moisture I breathe out from condensing on the windows and hatch above my head, it used to be so bad that it was almost raining condensation droplets each morning when the temperature was below 5 degrees C, but now I don't get any, they are still there is the mornings, but not big enough to rain down

 

[Billjratt]

Sounds like you don't have enough airflow behind those panels you removed.
Don't block anything up with insulation, you'll only create an airless void elsewhere. Have a sniff around, you can spot stale air easily.
If you have a gap between the hull and the furniture try to make sure it goes all the way across and along the boat, - so you have a boat within a boat, then make sure it's properly ventilated, and keep the bilge dry or it will evaporate and condense.
Don't close the dorades or any other vents. No damp, no smells, magic.

 

[Rigger Mortice]

I fitted polystyrene tiles and silver foil between the headlining & deckhead; seems to help a lot re.condensation ( don't get any there now ) and I like to think it's increased her radar signature ( in a fairly random, 'show up moving about in waves or to search aircraft' sort of way ) but I haven't conducted tests !

IIRC PBO tried that in one of its tests a few years ago. The effect was either zero or next to zero; certainly worse than the worst of the reflectors.

 

[Mistroma]

We had usual problem of condensation under mattresses.

Lagged water tanks underneath bunks with cheapo space blanket filled with mineral fibre. That helped.

Then we put down capillary matting under the mattress. Seems to work as we used to almost get puddles there. Alway dry now. Same idea as stuff you buy for boats but probably not as effective. Very much cheaper though.

 

[wazza]

If you are living aboard in colder climates, a solid fuel heater cuts out the condensation! Cosy too!!

 

[Robin]

The amount of moisture created is pretty much fixed by the number of occupants, the cooking and if gas the cooker itself and any combustion heating that is not using external air. All you can change is where this moisture goes which is always to the coldest point, like a hatch or a window. The only other alternatives are greater ventilation and dehumidifiers. On our sailboat we had a full cockpit conservatory so if on board in winter we would still leave the mainhatch at least partially open and the hatch in our cabin also even though we had heating running in there at night in the form of a thermostatically controlled fan heater (our eberspluttery was never used). When we left the boat in winter we had a dehumidifier permanently rigged with the drain into the galley sink.

 

[Seajet]

IIRC PBO tried that in one of its tests a few years ago. The effect was either zero or next to zero; certainly worse than the worst of the reflectors.

Err - the idea is it's supplementary to, not instead of, a reflector !

Considering the area & position, I'd expect it to give a useful return if & when the boat happens to be at the correct angle to the radar as far as surface kit is concerned, but may well help more with an airborne radar looking down.

Comes under the 'can't hurt' heading, not something to count on...primary function - insulation.

 

[PCUK]

Loft insulation behind every panel and foam back carpet on areas where there are no panels. My 26 year old boat has never suffered condensation and still smells sweet even closed up for several months. But then it's steel so was properly insulated from new! That's the answer. OH and perspex double glazed panels on window frames to stop window condensation.

 

[OldBawley]

Heating AND cooking on solid fuel.
If cooking on gas, the burning of 1kg of gas creates heat but also 9 litres of water. Think of the condense that gives.
Dehumidifier : crystals are sold to dehumidify. A better solution is to have the boat build out of five tons of bone dry wood. ( The extra tree tons of cast iron keel don’t help.) :

 

[mikemonty]

Condensation appears to be a way of life for boats especially if you are living aboard during colder weather.
Whilst cleaning and removing certain panels there is an air gap to the hull and these seem to be the problem areas.
Have you insulated your boat in any way, can it be insulated and besides a dehumidifier is there any other way to help cut down on the condensation?

Use the hull as a dehumidifier.
Water that condenses out on your hull means drier air and drier fabrics
Make sure that the cabin air can circulate around the surface but ensure that fabrics cannot contact the same surfaces.
The water that condenses out has to be able to run to the bilges.
Insulating the hull only cuts down the available condensing surface, makes the air warmer and able to carry a higher humidity, which will condense out as soon as the interior of the boat cools down - and it won't care where it condenses if it can't circulate to a colder surface

 

[Scotty_Tradewind]

Insulating the hull only cuts down the available condensing surface, makes the air warmer and able to carry a higher humidity, which will condense out as soon as the interior of the boat cools down - and it won't care where it condenses if it can't circulate to a colder surface

+1

Liveaboards especially are producing moisture within the boat and if it's too cold to ventilate well, it has to end up somewhere.
If there is no dehumidifier or cold areas for the moist air to condense on to then be wiped off, then it will most likely go into forming mould on varnished timber and/or produce damp fabrics.

 

[Sans Bateau]

Condensation on a boat? Mmm, never have that problem.

 

[Bodach na mara]

Breathe less.....

Reminds me of when I worked at Glasgow Nautical college and I saw a protest march of tennants of the nearby Hutchiesontown flats carrying banners about the dampness in the housing. One lady, interviewed on TV said "we've been telt no tae breathe!" I later was involved with environmental health officer training and found out the story behind that.

The problem in the flats was actually condensation, not penetrating dampness and was exacerbated by the tennants turning off the electric heating and using parafin and gas heaters. They also stopped the draughts. By blocking up the ventilators. At a meeting of the tenants, the EHO was asked "well if it's (the water) no coming frae ootside how is it gettin there then?" The EHO replied that the water was in the air in the houses due to what people did in them and outlined all the ways in which habitation raises the water vapour level. He listed all the usual suspects including drying clothes, cooking, bathing and foolishly ended up saying "even if you do none of these things, your sweat and breath delivers several pints of water per day to the air."

PS, insulation can make the problem worse. If the water vapour can penetrate the insulation and then comes up against a barrier, such as the hull, the vapour condenses and soaks the insulation. This was a big problem in the 70s during the first "insulate your loft" drive. Unfortunately the lesson has not been learned and the mistakes are being repeated.

The real message is that, to reduce condensation, you need to either stop living in the boat or both heat and ventilate it. Most of us are keen on heating, but we see the ventilation as lost heat and tend to reduce it.

PS. Insulation can make the problem worse. If the water vapour can penetrate the insulation (and it usually can) and then comes to a barrier, it can condense out and soak the insulation. This was (is?) a problem in many houses that were treated in the 70s "insulate your loft" drive.