Managing Moisture & Mold Aboard

I few days ago, I was restocking the diaper supply in the master stateroom (our bulk diaper boxes are kept in bow locker (right behind the head of our bed).  I noticed that the plastic packaging around the diapers was damp.  Condensation... ugh!

Bow Locker

I emptied out the locker and gave it a vinegar wash.  With the locker emptied, I noticed a floorboard that I had never looked under.  The floorboard gave access to the whole forward portion of the hull (it is a lot more steep and narrow than it appears in the photo) - MOLD!!

Mold - Before Clean -

I had my whole upper torso in this compartment (pleasant).  Again, I sprayed the area with white vinegar, let it sit for a couple minutes, and dried it meticulously. 

-After Clean-

My hope is that we have covered most of the boat and I wont find any more of these unpleasant surprises.  

Marine Dehumidifier - Managing Humidity

One of the main challenges for liveaboards is managing moisture, humidity, and condensation issues. 

In an effort to bring down humidity aboard Ma'alahi, we recently purchased the Eva-Dry 2200 Electric Dehumidifier from Amazon ($85):

Manufacturer's Product Description

We have seen a noticeable drop in humidity with the Eva-Dry (a 10-15% decrease).  We keep it running at night and during the day when the kids and I are running errands.  It is about as loud as a table fan.

To supplement the central heat and dehumidifier we use DampRid: 

According to DampRid's website, "... white calcium chloride crystals absorb excess moisture in the air, bringing humidity to an ideal and safe level..."  We use this product primarily in our bilge and it does appear to be effective (evident through water in the bottom of the container).  Our experience with DampRid is that it, used alone, will not reduce humidity drastically.    

T had a few of these marine dehumidifiers on his first boat (Pacific Seacraft 28').  He has an indifferent opinion on these and said that he did not see a noticeable change in humidity.  (They are in our garage sale pile). 

Heat & Moisture

Keeping a boat warm and dry is very important when you are living aboard.  

Heating aboard Ma'alahi has evolved over the last four months.

We have experimented with forced air electric space heaters (too noisy), a radiant heater (only heats objects in its path (not warm enough)), electric oil heaters, and our centrally installed hydronic diesel heating system.

Electric Oil Heater

Up until early September, we were able to keep the family comfortable with three electric oil heaters.  We keep the temperature in the main living area (where M sleeps) between 68 and 70 degrees (the recommended temperature for a newborn).

Since we have made the transition from Summer to Fall, our hydrometer has gone from 50-60% humidty to 80% humidity.  We did not see any visible signs of condensation in the main living area.  HOWEVER, when T inspected the hull, bellow the waterline and under the settees, he found that we had a slight moisture/condensation issue.  We were able to remedy this issue by switching from the electric oil heaters to our centrally installed hydronic diesel heating system.

The oil heaters were keeping the air in the living areas warm and relatively dry.  They were not powerful enough to warm the space between the settees and the hull, thus resulting in a moisture problem.

T and I carefully cleaned and dried all of the areas of the hull (bellow the waterline), that we could reach, in about 3 hours (using white vinegar).  Once these areas were clean and dry we started up the centrally installed hydronic diesel heating system.

Hydronic Diesel Thermostat

Since we started using the central system, the humidity has decreased substantially to between 55 to 70% (depending on the weather) and the hull has stayed dry.

Here is a brief description of how our heating system works: (from ITRheat.com)

"The circulation of hot water to provide heat is known as a “Hydronic” System. It is a closed system continually circulating the same coolant. It begins with a furnace or boiler, usually fueled by diesel, or electric elements that heat the coolant up to 180 F degrees. A water pump circulates the hot coolant through a domestic water heater and then to the various fan units located throughout the interior of the yacht..."

My understanding is that these systems are very expensive (labor intensive) to install.  Ma'alahi came with this system.  The prior (and only) owners had the system installed when they purchased the boat in 2001.  

T estimates that we use about four to five gallons of diesel per week.  This means approximately $80-$100 per month in fuel.  We will see what happens (as far as expenses go) as it gets colder.  We are happy that we are warm and the boat is dry.