Bloody condensation.!!

TNT

TNT

Well-Known Member
Joined
4 Oct 2007
Messages
258
Location
Lefkas-Greece
Visit site
OK, we are now permanently on board in Cagliari and I am sure that this has been asked before but how the hell do you stop condensation.....or can you not? We have a small dehumidifier and leave it running in the front V berth but still wake up to drips on the head in teh mddle of the night, the weather at the minute does not allow us to leave the hatches open for circulation....hitty missy rain. Has anyone had any good results with the solar vents? .........anyone got any miracle cures to stop it?...........I am sure it would be a .com if there was but any help appreciated.
 
First, think about where the water is coming from: cooking, heating. Work out if you can reduce it. Your breathing may well be a significant contribution.

Second, you must have ventilation: relatively dry air coming in to displace moisture-laden air inside.
 
what heating are you using are your vents blocked etc,if using gas can get a lot of condensation ,i used to use a kabola diesel heater and a dehumidifier and added several more vents no problems at all also bought a 60 watt electric blanket saved untold amounts of cash
 
bloody condensation

Thanks all, I had considered the ebberspatcher route but after posting on here the evidence did not seem very conclusive, weather they helped or were they just pumping air around the boat. The dehumidifier issue on PBO seems to be a livley discussion, personnally I will keep mine running as long as possible the temperatures here will not warrant the freezing issue.
oh well back to the kitchen roll to hand tonight,.
thanks
 
TNT said:
. . . .anyone got any miracle cures to stop it?...........I am sure it would be a .com if there was but any help appreciated.
Click to expand...

I haven't got a cure but you could easily stop the drips on your head by somehow pinning a sheet across the area above your head whilst you sleep and any drips will fall onto the sheet and not your body. :)

I offer the following links which might point you in the right direction to change the Dew Point and limit the condensation:

http://www.windowstoday.co.uk/condensation-explained.htm

http://en.wikipedia.org/wiki/Lifted_condensation_level

http://www.chuckegg.com/where-does-dew-come-from-dew-point-condensation/

http://www.brighthub.com/environment/science-environmental/articles/48969.aspx

I hope this helps? :)
 
Condensation

Ventilation is the answer. We have a cover over ther front hatch so it can be left open. We also have a cockpit tent so can leave the main hatch open. Warm air rises and condences on the tent windows removing the moisture. We are also in Turkey so that helps but only in that we can leave hatches open more.
 
condensation

Hot air blown around all the boat with a WEBASTO or MIKUNI heater,(these two are easy to service) then put a second skin over the boat, not high so that the wind destroys it, but close down,( a 6inch gap deck to skin ie. plastic sheet) then your problem is only exposed boat sides,

It helps if you have a good air gap above your inside roof lineing,
no need to keep hatches open, the normal vents are suffient,

good luck
 
On my catamaran I manage very well by having a lot of cross ventilation:

In each hull I have a venturi type vent at the front, a dorade type vent in the middle section and another one at the forward end of the aft cabin. Then at the aft end of the aft cabin a solar powered ventilator set on extracting the air.

The main cabin between the hulls has air coming through vents at the forward bulkhead and again a solar powered ventilator to extract the air which is located on top of my main cabin structure. I can also open forward facing hatches in the main cabin.

If you go for solar powered ventilators I would advise you to get those with solar charged batteries, they run just that extra mile when you need it!
 
We installed a "Nicro" solar powered vent with a nicad battery in the hatch over our v berth... It was set to exhaust all the time, and it worked very well to cut down on the condensation, especially at night.... Nothing like cold drops of water in your face when you are sleeping.... Here's a link to the type that we used:
http://www.marinco.com/product/daynight-plus-vent-stainless-steel-cover

We also installed a Vetus 12V fan in the galley to exhaust any hot air/moisture from cooking. It would also evacuate a lot of hot air so that our air conditioning would cool down the boat faster.

On our trawler that we live on now...we have four of the Vetus 12V fans... one in each of the heads to carry out moisture, one in the galley, and one in the salon. They move a lot of air, and make a definite difference in the humidity and condensation issue. With the Vetus fan you have to pick either a mushroom style vent for horizontal use or a clamshell for vertical installations.

Hope that helps!
 
Bloody Condensation

I like the idea of the solar extractors but heard so many bad stories about them leaking in the heavy stuff when fitted in V berth coachroof or hatch. Have you had any problems with water getting in when its rough?
 
Warmth isn't really the issue - though it's a shame to have such a problem in a great town like Cagliari. We had three liveaboard winters in the UK and ventilation and insulation are the keys. We've posted on this many times but will say again:

- ensure a free flow of air (this is what the heaters are doing to help, much more than the actual warmth). Covering hatches, including a cockpit tent, so you can leave them ajar, makes a big difference. Also try and keep clothes lockers ventilated eg with rattan type material in the centre of the hatch, and have some air circulation under your mattress (eg slats from IKEA, Ventair etc)
- reviewing your sources of heat for how damp they are. Your gas cooker, for example, generates moisture
- insulate - particular in the cabin where you sleep. Insulation under the headlining, against the hull down to below the water, on the underside of the locker hatches beneath your bed
- move things about regularly - eg turn your mattress once a week, and check for particular condensation traps so you can work out a way to solve them.

Our first winter we struggled but once we'd got these issues more under control. Frankly a dehumidifier cannot cope, and the noise keeps you awake. Solve the problem, not the symptom.
 
TNT said:
I like the idea of the solar extractors but heard so many bad stories about them leaking in the heavy stuff when fitted in V berth coachroof or hatch. Have you had any problems with water getting in when its rough?
Click to expand...

Whilst my solar ventilators are at the back and out of the way of heavy water cascading over the deck and they have proven to be waterproof even in torrential rain (I did use a liberal amount of sealant!), I would NOT install any solar powered ventilators at the front of a boat.

In my mind you'd be much better off to install one of these dorade vents at the front

http://www.air-onlyventilators.com/main/

and one or two solar powered ventilators somewhere further aft, the further aft the better. If you want to / have to / can then put a stainless steel "sheet preventer" (sorry, can't remember the correct nautical term!?) over the dorade vent.

"Air IN at the front of the boat and air OUT aft"
(which is of course especially true when you are swinging to the wind when at anchor).
 
Hi
We find on our cat that the windows produce 90% of the condensation on the boat and that in the forecabin it drips onto the quilt, particularly when outside it is below -2deg c. The solution that works very well for us is to insulate the windows (and the frames) outside which completely stops any dripping and in the morning leaves only a slight misting on the glass which soon clears itself. We use thin closed cell foam (about 4mm) as covers over the windows. Not very easy to source suitable stuff but Yoga or Floor exercise matting does the trick-well worth a try, only taken me about ten years to work this one out!
 
Window covers....

We were with friends for drinks last night in their motorcaravan. They'd covered their windscreen and door windows with an insulating "blanket" fitted to the outside. All of the vans on the site had these window covers. Effectively it moves the temperature differential surface to outside of the glass and therefore the condensation forms externally. Brilliant! Our Nauticat has proved very well insulated indeed with absolutley no condensation except on the pilot house windows; hopefully the motorcaravan solution will solve that problem as well. My motorhome friend advises that "Caravan Monthly" has details of firms that make these insulating window covers to fit any situation; we're going to try it and we'll report back when we've first hand experience.
 
Last edited:
>We have a small dehumidifier and leave it running in the front V berth but still wake up to drips on the head in teh mddle of the night

Get a bigger dehumidifier, it should take out at least 2.5 litres of water overnight. As you say you can't always open hatches and anyway to stop condensation you have to have so much ventilation to cool the boat that the temperature becomes uncomfortable. Been there tried that.
 
You must log in or register to reply here.

Share this page

Top