Dealing with Condensation

[avril25]

I was wondering how people who live aboard deal with condensation that develops on the walls and ceilings. in winter or summer. Does insulation help.
what type of insulation works best. I see a DIY spray on high density foam,
1 inch equals 7.7 r factor Has anyone tried this. Do those electric dehumidifiers work. Any suggestions.

[barnakiel]

We deal with it by moving to places where the water is too warm / air too dry to allow for condensation.

Having a sandwich boat helps a bit. Having a Sadler or Etap helps another bit.

If you cannot move the boat or replace her with an Etap then make sure the air circulates and a lot - it will take out the moisture and there will be no or nearly no condensation.

b.

[Rick]

Several of us on this forum liveaboard with a Soleusair dehumidifier. My boat is well insulated EXCEPT for where the hull meets the deck. That is where the condensation occurs dripping down into all lockers. So, the insulated hull keeps heat in/out yet one still needs to dehumidify when livingf aboard, especially if you use propane cooking for any length of time.

Other brands of dehumidifiers do not necessarily work at cold ambient temps. The one that I had previous to this unit would barely work at 60 deg F and even then would freeze up often. The soleusair will work down to 50 deg F.

I have two hygrometers on board to monitor the humidity and discovered that if you keep the relative humdity to 50% mold and mildew do not happen, allergies do not happen, condensation does not happen, and one is more comfortable with lower ambient temperatures in the winter and higher temperatures in the summer than with higher humidities.

In addition, I've measured the power factor which is almost unity with this new technology. As you might know most refrigeration compressors (used by dehumidifiers as well) create a large lagging power factor unless compensated for thereby limiting the 30A shore breaker rating to a value less than 30A.

[sneuman]

I haven't found it to be too much of a problem here on the Chesapeake. I have never had condensation on the coach roof. There's some on the hull, but it normally is just a sweat that ends up in the bilge and is pumped overboard.

Everybody talks about this being a huge problem, but honestly it hasn't been for me.

[michaelmrc]

one of the areas i found to be problematic on my boat was under the vberth mattress. a little condensation in the lockers which i rectified by adding a couple of 12 volt computer fans.

[David M]

Spray on foam does help. I have an aluminum hull with spray on foam everywhere where there is wood paneling over it and the foam works.

[Hurricane Harry]

Insulation makes a big difference./Harry

[bstreep]

Dehumidifier. Works GREAT.

[Bash]

i use a Soleus CFM-40 dehumidifier. Works great and is far more quiet than most others.

[GordMay]

I’ve heard other very positive reports on the Soleus CFM-40 Heat Pump* style dehumidifier. The unit features a continuous drainage port*, but the 15mm discharge hose is not included.

* Heat pump dehumidifiers are the most effective, & also most costly type to purchase & operate.

At 20 liters/day capacitry (40 pints/day), the 6 liter (automatic shutdown at ~ 5.5 liters) tank is too small for tropical use, unless the continuous drain modification (simple) is effected.

[bstreep]

Yes, ours is a Soleus-40. Works great. Only ONE complaint:

When the power goes off (like when the marina loses power), the unit turns on, on "standby" - ie, not running.

[fishwife]

Originally Posted by avril25

I was wondering how people who live aboard deal with condensation that develops on the walls and ceilings. in winter or summer. Does insulation help.
what type of insulation works best. I see a DIY spray on high density foam,
1 inch equals 7.7 r factor Has anyone tried this. Do those electric dehumidifiers work. Any suggestions.

Ventilation followed by Ventilation, even if you have to allow costly heating to escape into the cold unwelcoming air.

[Roaring Girl]

We lived aboard three winters in the UK before heading south to the Med. Some thoughts:

(i) ventilation, ventilation. Drill holes in your locker hatches/replace with raffia, have good vents and funnels, keep the companionway open a crack
(ii) insulation really helps. We looked at spray on but you need to really, really clean up and it's a huge job. We stuck 9mm (though 6mm would do) closed cell foam all over the inside of the hull to below the waterline, which made a huge difference. Also stuck on the underside of locker lids under bunks.
(iii) use something under your mattress to help ciruclation. We use ventair (tm) - a woven matting. Some people use coir (which didn't work for us) and others the kind of bendy slats you can buy from IKEA. (Do you have IKEA in the US?)
(iv) think carefully about how you heat and cook - some fuels generate more moisture/humidity than others and that must be compensated for. Again your cost of electricity will matter a lot here.
(v)) use a dehumidifier if you have the space and the electricity. In the end we settle for 12amp little ones and emptying them regularly.
(vi) don't assume you can dry clothes below; you will need to use the dryer at the laundrette, if it's too cold/wet to put things on the line.

[BarnicleBill]

THE BEST DEHUMIDIFIER is a small wood stove that will burn pelets or drift wood,or charcoal and doubles as cook stove. I HATE propane cook stove in small spaces they need a good fan hood over them . if your boat is small like mine, I have honda 1000 wat generator and a750 w hot plate and drip coffee maker . the honda has a 12 vdc 10 amp charger , it will run about 3 hours on gallon at load

[GordMay]

Fishwife & Roaring Girl offer some good advice, but under-emphasize ventilation.