Drying a computer locker

[fallguy]

I have a Glendinning actuator in the stair steps of my catamaran. The actuator drives the throttle and clutch to 90hp ob by wire to the helm and from under the steps to the engine mechanically.

The space also includes start batteries and a fuel filter.

The actuators cost about 2k each.

I'd like to setup some way to minimize the humidity in the chamber. The chamber is open for incoming lines to areas forward.

I was thinking maybe something like a pc fan with an RH sensor/relay. It would only kick in when the RH was high inside the chamber and also would not drive my start batteries down; so would not kick in under low voltage.

Anyone able to draw it up? A small bit of heat may help.


I think I might try to use a gorevent as well, but need to research if the gorevent would allow a higher exterior humidity back into a drier chamber.

If anyone has experience keeping lockers dry without access to heating systems; please coin in as well.

 

[bajansailor]

I know nothing about Glendenning actuators, but it sounds like a complicated system to have - the 49' cat in my avatar has 2 x 150 hp O/B motors, and she just has simple Morse type control cables going from the engines to the flying bridge in round pipe ducts.
I cannot remember the length of the cables, but I think they are at least 20' long.

I think we got them from Lewis Marine (this was 20 years ago).
https://orders.lewismarine.com/show_catalogpage.php?Book=Base&Year=2019&Page=537

 

[fallguy]

I know nothing about Glendenning actuators, but it sounds like a complicated system to have - the 49' cat in my avatar has 2 x 150 hp O/B motors, and she just has simple Morse type control cables going from the engines to the flying bridge in round pipe ducts.
I cannot remember the length of the cables, but I think they are at least 20' long.

I think we got them from Lewis Marine (this was 20 years ago).
https://orders.lewismarine.com/show_catalogpage.php?Book=Base&Year=2019&Page=537

remember my cat is demountable; rather than trying to get cables adjusted each time; the by wire method is the route I am going; the actuators are already here

 

[bajansailor]

remember my cat is demountable; rather than trying to get cables adjusted each time; the by wire method is the route I am going; the actuators are already here

Righty ho - my apologies, I was thinking that the assembly would just be a one off occasion after you take her to the coast.
Will you be dis-assembling her each year to bring her home for the winter?

 

[Rumars]

Pelican case (or similar 100% waterproof box, Al if heat transfer is needed) mounted into the compartment with the actuator inside. Waterproof cable glands for the electrical wires, corrugated rubber boot sealed on the morse cables. Toss some silica xerogel with indicator in the box, close the lid shut and inspect at least once a year.

Goretex works by pressure or temperature differential, moist air will go in.

 

[fallguy]

Yes. The cables will be well rigged.

silica xerogel, thanks, will research

No room for the Pelican case.

 

[Rumars]

I don't suppose you could make the whole compartment gastight?

Silica can be bought in bulk and reused, after it changes colour you dry it in the oven and it's ready for another round. A big bag changed regularly will keep the compartment dry if it is reasonably watertight.

 

[fallguy]

I don't suppose you could make the whole compartment gastight?

Silica can be bought in bulk and reused, after it changes colour you dry it in the oven and it's ready for another round. A big bag changed regularly will keep the compartment dry if it is reasonably watertight.

it would be difficult, but possible to get it close; the problem is the hatch lid mainly...it is plastic and the rest of the thing is foam core; so condensation is more likely; it might be possible to put insulating foam on the lid..if it'd stick

 

[fallguy]

I have no experience with your actuators. I have however installed computer fans in order to move some air around in an electronics cabinet as well as up in the v-berth on my boat. These fans have eliminated condensation which is your goal.

I used this little timer. https://www.amazon.com/Uxcell-a12031200ux0078-Power-Programmable-Switch/dp/B008999RYY

It's been cycling my fans on and off since 2013. Never had a problem with it. These timers can be set to cycle on and off up to 17 times in a 24 hour period. I set mine to activate every two hours for about 30 minutes.

Computer fans are 12 volts, so it's easy to wire into a 12 volt system. These Noctua fans give you adapters to slow down the fans if you want to.

https://www.amazon.com/Noctua-Ultra...f-p14+flx&qid=1602637506&s=electronics&sr=1-7

Power draw is extremely low for these fans and they move the air around effectively. Noctua reports a maximum power consumption of 0.96 watts or 0.08 Amps at 12 volts. With that kind of power consumption you shouldn't need to worry about running your house bank down from the fans.

I like the idea of a humidistat relay. I could set it for say 60% and if the fans kicked on, I'd know there was water in the box.

Right now leaning toward a tub of dessicant. Just trying to find the right dispensing method as I also don't want dessicant to fall down into a dry sump I have there...it is a tricky space..bit small

 

[Mr Efficiency]

There are various materials that absorb moisture, that are cheap enough. Just need to replace when they have reached saturation. Reusable after driving off the moisture with heat.

 

[sdowney717]

A problem I have noticed with my onboard PC in a side locker is condensation. Not much to do about it except if you can raise the temperature of the area to keep the water in the air. One way might be to leave the computer on all the time when the fall weather arrives. I am thinking that is one reason why eventually my onboard desktop PC fails, it rusts and shorts from the moisture in the air condensing on the circuit boards. I get at least 4 years from a PC before it no longer boots up. Maybe an old style light bulb to use as a heater, except they do burn out. I have seen the engines drenched wet with condensation when the air is very humid and the temperature drops down at night. I setup the PC with win10 for a navigation PC and have a larger TV used for the display. HDMI and USB long cables. USB is about 21 feet but it still works fine including with a USB GPS. I have a USB hub at the display, so plug in a GPS, Keyboard, mouse, etc... I have thought about using a mini PC right at the display which might be more sealed. They are getting more powerful. I have used old desktop PC's for many years as they were cheap, easy to build and get parts for. I use OpenCPN and NOAA ENC charts, both are free to use. Of course being a cabin cruiser, it is all interior, no rain and no waves getting things wet. And I have dual helm. I like the lower helm much better than the flybridge.