Posted by katorpus (jrb@…>)
I use the “full-size” one in my Freedom 40 (more cabin space).
If you get one with the humidistat, it won’t run any more than
it “has to” to maintain the humidity level which you set.
Here’s how I use mine…
I placed it on the galley countertop beside the galley sink, with a
short piece of garden hose leading directly to the sink strainer
(which doesn’t have to be in place). The hose connects to a fitting
which was molded into the “bucket” for the dehumidifier just for that
purpose.
After going through several of the cheapie “dial type” on-off timer
switches, I bought one of those ($50 or so) gray metal box wire-in
timer switches like the kind that you use for outdoor light circuits.
You have to wire up the pigtail to plug it into the wall, but that’s
easily done.
I set the humidistat for about 60% relative humidity, and set the
timer to run for 12 hrs a day beginning at dawn. My interior stays
dry enough that the floorboards creak. There is no such thing as “too
dry” where the interior wood is concerned.
I also use a Quantum ozone generator plugged into to the power strip
that’s wired into the timer box.
I keep the boat closed up tight with no outside air circulation. I
never have any mildew, “boat smells”, nor stink of diesel down below.
Several things to consider…In cooler weather, a more-or-less
continually running humidifier will freeze up (on the coils of the
unit). Hence the timer and the timing (daytime running, when it’s
warmer).
These things do put off some heat. Expect it to warm up the interior
of the boat quite a bit when it’s running.
If you drain a dehumidifier into your shower sump, you’ll
be “exercising” the pump (associated with the sump) quite a bit. If
you can place the unit where “gravity” does the work (like over a
sink) then, assuming you don’t close the through hull for the sink
when you’re away from the boat (I only do this when a serious storm
is approaching), then it won’t “cost” you anything to get rid of the
water that’s extracted from the air.
The sump pump won’t wear out, and you won’t be re-extracting the
water from the air that results from it trickling into the shower
drain and/or sitting in the sump awaiting a pump cycle. If it takes a
pint of water to “trigger” your shower sump, and your dehumidifier
removes 20 pints a day, then assume that you’ll have at LEAST 20
cycles per day of your sump pump (more actually, as the motion of the
boat in the slip will likely trigger it more often due to sloshing).
A less-capable (hence less-efficient) dehumidifier operating more
hours per day will not save you kilowatt hours.
The bigger ones ARE more of a pain to move around when you get ready
to go sailing, but they’ll fit in a dock box.