Aft cabin condensation!

[valhalla360]

More heat won't do much. It's like on a hot day a cold glass of water will develop moisture on the outside except the inside of the boat windows is the outside of the glass.

A dehumidifier is the best option with insulation around windows and frames a good secondary help.
- The damp rid helps but gets used up quickly. We found it impractical for anything more than a small closet.
- Ventilating will help but it undermines your heating.

[Ribbit]

Originally Posted by a64pilot

I just got this dehumidifier and it is outstanding, my old one was noisy as all get out, this one sounds like a dorm fridge and a fan, very quiet. I drain it into the bilge or I would be emptying the bucket daily.
I don't live aboard though and don't have any experience with your level of cold.
Amazon.com: Frigidaire FFAD5033R1 Energy Star Dehumidifier with Effortless Humidity Control, 50 pint: Home & Kitchen

But a humidifier will add some heat, they are nothing at all but an air conditioner, the water collects on the cold evaporator and the air is re-heated by the condenser, since energy is being expended, heat is produced. It won't heat a room or anything, but at least it's not cooling.

Oh, and once you get it dry inside it will feel a lot warmer than the same temp with condensing humidity

Warm air + high humidity = nightmare.

Cold air + high humidity also = nightmare.

As A64 says, getting the air dry will make a massive difference.

The dehumidifier A64 linked is very nice, uses about 530 watts, and has a water container that will hold about 13 pints (over 7ltrs). It will remove up to 50 pints of water a day (obviously once you have dry air, that will go down).

You have to be really careful with the small dehumidifiers, because a lot of them will only remove a few pints of water a week, and can't really cope if water is constantly being added to the air (handy for clothing cupboards and such really).

In fact I was seriously considering a 70 pint watermaker over even a 50 pint, but after A64's comments, I am rather reassured (given the internal volume of his 38ft over the 32ft I'm buying).

Now if you are using a 2kw heater presently (on shore power I assume), have a look for a ceramic electric fan heater, that has a high power position of 1.5kw, and a low position of 750watts.Odds on it will be the same one I have, and it's a real belter for the money. You will then have about the same power usage as you have now, and will probably be warmer and far more comfortable, without the damp.

This is the heater I have, but it was a lot cheaper with a different name on it, and it oscillates if you want, plus the tip over is sensitive - it switches off when I pick it up, and restarts when I set it down on its base:

http://www.walmart.com/ip/Optimus-Po...ostat/20893860

A dehumidifier and a steam cleaner (kills mold and spores, along with other nasties), are the first things I am going to get for my boat.

PS I am going to save all the water from my dehumidifier, and put it into containers with a little bleach to kill any nasties off, then I will use it for showers, washing clothes, rinsing sails, rinsing the decks, and such. This will make my 65 gallons of water tankage go a lot further.

[a64pilot]

The dehumidifier I linked has has a display that shows current humidity level, and you can set the desired humidity and the compressor won't run when that level is reached, fan runs always though. It will drive it down to 30% or lower in my boat, with us in there, four people.

If you save the water, it may not be potable, true it is distilled water, but there is a possibility that the evaporator coils could have lead solder or something, I doubt that as they are aluminum but, still maybe don't drink it. Should be good for the batteries though.


Sent from my iPad Pro using Cruisers Sailing Forum

[Training Wheels]

We use the Eva dry EDV 4000. It's not cheap, but it's great. Liked it so much we bought another. It's smaller and lighter than the other dehumidifiers, and quiet. Most dehumidifiers are noisy! We run this one in our aft stateroom all night, and basically it's just white noise.

[hellosailor]

It is distilled water, but apparently a bigger issue than any metal content (they usually use aluminum tubing these days, not soldered copper) is that no one every thoroughly cleans the coils, so all the airborne microbes, fungus, bacteria, can settle and breed in there. Think "Legionnaires' disease".


You could always let it run a few months then send out a sample to a water test place, county offices sometimes do that for free and Home Depot often has racks of free water test kits (from a vendor hoping to sell you filter kits) but I suspect it would be safe to drink if boiled or otherwise sterilized.

[Tri]

Does anybody have any experience with 12V dehumidifiers and could you recommend one from your own experience? Thanks

PS I know 12V is very little for this but I can't offer more. No shore power or inverter.

[Tri]

Anybody have any experience? :-)

[Ribbit]

Originally Posted by Tri

Anybody have any experience? :-)

Not actually used one, but looking at the amp hours used - about 6 - for a bit better than average one, you are still only removing up to 20 oz of water a day (for about 140 amp hour drain on your battery!).

It seems an awful lot of power for very little effect.

It's why I am going with the very nice bigger 50 pint a day unit a64pilot linked. No problem while on shore power, of course, then when at anchorage (having started off with a nicely dried and aired interior, pretty free of molds and spores) with solar panels topping things up, I'll restrict its use to a maximum of 2 x 2 hour periods a day, to cover the main cooking periods of lunchtime and evening meal. For me I think those are the most critical to be able to keep well on top of damp, molds, and spores (they are particularly bad for me).

That total of 4 hours use will draw about 160 amps from the 660 to 880 amp hour battery bank (to remove about a gallon of water total per day), so if the solar panels can't keep up, I'll begin to fine tune by using it for perhaps a half hour at lunch time, just after I have finished cooking, then a good two hours just after cooking the evening meal, which will maybe have the best impact for keeping bedding aired, etc., which would have it removing about 5 pints a day.

I'll be watching the state of the batteries via a voltmeter (never go below 12.2v apparent for long and reliable FLA battery life), like a hawk though.

[valhalla360]

Originally Posted by Tri

Anybody have any experience? :-)

Not with 12V units but one time the air/con (which performs dehumidification) started leaking into the bilge (the condensation on the coils).

This went on for around a day before we noticed. There was about 6-8 gallons of water in the bilge we sucked out with the wet/dry vac.

[Ribbit]

Originally Posted by hellosailor

It is distilled water, but apparently a bigger issue than any metal content (they usually use aluminum tubing these days, not soldered copper) is that no one every thoroughly cleans the coils, so all the airborne microbes, fungus, bacteria, can settle and breed in there. Think "Legionnaires' disease".


You could always let it run a few months then send out a sample to a water test place, county offices sometimes do that for free and Home Depot often has racks of free water test kits (from a vendor hoping to sell you filter kits) but I suspect it would be safe to drink if boiled or otherwise sterilized.

Very true, it's worth being extra cautious with the water output (why a watermaker is still very much on my shopping list).