I’m trying to figure out ways to...

[DJH]

I’m trying to figure out ways to keep my engine compartment dryer or at least less humid. My mechanic recommended leaving the hatch cover open a inch or two when the boat is not in use. I’ve been thinking of about putting a small dehumidifier down there and having it drain to the bilge pump area. I’m wondering if there are any safety concerns related to gas fumes as the dehumidifier turns itself on and off.Any thoughts?

[wingless]

Do not put a dehumidifier into the engine room.

The dehumidifier has a compressor motor, has a automatic humidity sensor contactor switch and a fan that all generate sparks. All of that is incompatible w/ the requirement for ignition protection.

Nothing wrong w/ humidity. It is condensation that is a greater problem.

For example, I keep the air circulation fans running 24/6/365 in the salon to avoid moisture problems when the boat is idle.

The boat already has engine room exhaust fans, but I wouldn't want to leave them running continuously. They are too loud and I wouldn't want to suffer failure on this important part

If this needs a solution, then maybe a smaller (less airflow / noise) exhaust blower could be added for idle operation. Those marine blowers already have ignition protection. It would require a fuse for proper / specified low current protection.

[DJH]

Wingless, thank you for your reply.

[Mike_s_boat]

Try putting a damprid bucket in there. You can buy them at any hardware store.

[cbruck]

A lot of larger yachts use dry rods, Goldenrod is one of the better manufacturers. But as Wingless warned about, be careful of sparks which can even be caused by plugging a cord together. I would open the hatch with the blowers on and plug the dry rod to ac outside of the engine compartment, then place them inside and you'll have to leave the hatch open a little anyway for the ac cord. I don't have direct experience but have heard that they work well.

Just search online for Goldenrod dehumidifier and there are various manufacturers that make them.

[camillotom]

you can install a programmable electric switch that runs 1 hour per day, or more, a bilge blower, so that you force the ventilation of the engine room. the bilge blower is built with spark free engine, so you do not have the risk of ignition matter.
but i think the most effective is the mechanic suggestion, easier, effective, money saving..... just put a wood tack or a piece of insulating board to keep the hatch open.

[M___K]

We have the 40 MY witg twin engines… the bilge pumps can’t get the low water, so it leaves 1/2” or so… same issue… wanted dryer air there. Installed the Seaflo Dry Bilge pump system with timer box… about $150… works perfectly! Have a bone dry bilge… no musty smell. Here is the link:
https://www.seaflo.us/product/dry-bilge-system/

[wingless]

That dry bilge system looks nice.

The factory built my 2000 380DA w/ bilge pumps having check valves on the hoses, to prevent drain back when shut down.

My experience is that the pumps don't work when the bilge is dry, probably because of those check valves. They work great, without issues, when water level remains from the switch toggling off.

That dry bilge system should not be used if the pumps won't work normally starting from dry, like on my boat.

[M___K]

Yes all bilge outlet hoses should have check valves. I agree. However bilge pumps, because of the mounting can’t get all of the water. Tgey get it pretty close but nothing bone dry. That’s where the Dry Bilge system is so effective. Just my experience witg my installation.

[wingless]

According to Page 10 on the linked Rule bilge pump Owner's Manual, there should not be a check valve on the output hose.

https://www.xylem.com/siteassets/brand/rule/resources/manual/rule---360-2000-standard-bilge-iom.pdf

[Final_Frontier]

What specific check valve for the bilge pump do you recommend? And, if water does reside in the bilge hose due to the check valve, does one need to empty these prior to winter (freezing) storage?

[wingless]

For certain, the hoses retaining water because of check valves must be drained or must have water displaced by appropriate antifreeze.

When I would winterize my boat I drained all those hoses by disconnection from the check valve. A blowing shop vac is useful to purge water on long horizontal runs, probably not essential.

A check list was created by me to ensure I performed all winterization tasks each year.

[Final_Frontier]

Wingless, would share your winterization check by PM?