Best practices for a dry interior

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jhance

Senior Member
Joined
Nov 1, 2017
Messages
236
Location
USA
Vessel Name
Audrey Grace
Vessel Make
2003 Camano 31
I've struggled a bit with the exact best practice when aiming for a dry interior and dry storage areas. Of course, ventilation, air movement, and a little heat are good.

Here is my current plan of attack for my Camano 31 in the Pacific Northwest:

1. low-watt fan/heater in engine room
2. low-watt fan/heater on v-berth floor
3. Small fan on low at forward end of salon floor pointing up and to a slightly-cracked window at stern
4. Head window open a crack
5. Damp-rid closet dehumidifier bags in v-berth, chain locker, and galley

My thinking here is that the fan exhausts air out through cracked stern window and pulls air from the v-berth/head area. But I struggle with opening any windows because I think all I am doing is letting in cold/damp air and my damp-rid bags just collect atmospheric moisture!

What combinations of open windows/fans/dehumidifiers/heaters are you all running for a boat that is kept in the water and used year-round?
 
I've struggled a bit with the exact best practice when aiming for a dry interior and dry storage areas. Of course, ventilation, air movement, and a little heat are good.

Here is my current plan of attack for my Camano 31 in the Pacific Northwest:

1. low-watt fan/heater in engine room
2. low-watt fan/heater on v-berth floor
3. Small fan on low at forward end of salon floor pointing up and to a slightly-cracked window at stern
4. Head window open a crack
5. Damp-rid closet dehumidifier bags in v-berth, chain locker, and galley

My thinking here is that the fan exhausts air out through cracked stern window and pulls air from the v-berth/head area. But I struggle with opening any windows because I think all I am doing is letting in cold/damp air and my damp-rid bags just collect atmospheric moisture!

What combinations of open windows/fans/dehumidifiers/heaters are you all running for a boat that is kept in the water and used year-round?

Wifey B: Air conditioners with dehumidifier settings. :hide:
 
I come from sailboats and tackled the moisture problem while living aboard. I'm also a science geek and use it to my occasional advantage!

Cold air is dry; it cannot hold as much moisture as warmer air.

I put a fan in a vent at the stern to draw in outside air and another in the forepeak to exhaust it. A simple space heater (doesn't need to blow air) inside, located aft, warms the air. As the air warms it absorbs an enormous amount of moisture.

This doesn't have to be a big, powerful system. I used a boxer fan from a computer ducted through a vent at each end of the boat. The trick is to make sure that all other windows, hatches and ports are tightly closed so that a gentle, low-volume flow of air through the length of the boat is maintained. It takes very little power to raise this slow-moving air a few degrees before it is ejected.

Bring it in, warm it up, then send it outside. It works really well.
 
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We live and work aboard in Port Ludlow, so we're on the boat essentially 24/7. Been doing it for 5.5 years now. Beyond the propane fireplace (with double-wall stove pipe) in the main salon to keep the main deck nice and toasty, here are things we employ each winter to keep our entire home warm, dry and comfortable. In no particular order...

1. 2 household size dehumidifiers fore and aft. We typically run one at a time, but only for 4-5 hours. We TRY to run one daily, but don't always. They remove an AMAZING amount of water from the air!

2. Heat shrink plastic on the main salon windows. Keeps condensation off the windows and does a very good job of keeping the heat in/cold out. We can even boil water for pasta, etc. and the windows stay clear.

3. Wallas forced air diesel heater. We basically turn it on in October and run it 24/7 until June. Even on the lowest setting, it keeps the lower deck staterooms warm all winter long (we do turn it up when the temps get into the 20s and 30s). Also, does a good job of constantly circulating air.

4. H2Out Space Dryers. We have 15 of various sizes placed throughout the boat (we sell them in our online store). Keeps moisture out of lockers and cabinets. And they're infinitely reusable.

5. Kanberra Gel. We have a bunch in place throughout the boat. Does a great job of keeping mold and mildew from growing. Really good head spray, too!

And on nice days, we open things up a bit to air the boat out.
 
I use Air conditioners with dehumidifier settings in the summer and a Mermaid Dry Pal in cooler weather. The Dry Pal produces additional heat which I find unacceptable in the summer.

dry_pal_dehumidifier.jpg


The Cummins diesels, "my Little White Monsters" are equipped with Wolverine pan heaters which keep the engines toasty and the engine room dry.

M25-120V_760x.jpg


I use this combination year round and the boat is always dry and sweet-smelling and the warm engines start instantly with minimal smoke.

There is an energy cost involved, but the reduction in mold, mildew and corrosion damage to engines, equipment and electrical systems easily outweighs it.
 
I am convinced that the most efficient way to keep your boat dry in the PNW is to use a dehumidify. I have use the small household dehumidifiers in my boats for years to great effect.

This last year I switched to using Eva-dry units. I have two of their larger units and one of the smaller. They take less electricity and are much quieter than the the home style dehumidifiers that I have used in the past. I use a Wolverine oil pan heater on the engine, and then one of the Davis Air-dryr type units in the salon to provide just a touch of heat. It works great and keeps the boat very dry.
 
Small household dehumidifier works great on my ride. When at the dock at the house, I just dump the bucket once a day. When I am away from the boat, I set up a hose where it piddles into the head sink or aircon sump. It uses much less power than leaving the AC on in dehum or AC mode. It tends to run at night when cooler temps increase RH number (not the same as moisture content, that remains constant with temp), and when sun warms the boat RH drops and machine goes idle. Perfect.

The desiccant type dryers need some sort of regeneration or replacement of the desiccant once moisture loaded. No such need on a refrigerant type.

Refrigerant typ runs about 200 bucks at a home store.
 
Caframo stor-dry in the head. Eva-dry in the galley. Oil-pan heater. Hatches cracked. I agree with Sabre602. Read a book about it years ago, in which the author uses smoke to watch the airflow.

The eva-dry works well until it freezes up. Can even keep the glass condensation free on the occasion that I sleep onboard, in harbour, in the winter.
 
We live and work aboard in Port Ludlow, so we're on the boat essentially 24/7. Been doing it for 5.5 years now. Beyond the propane fireplace (with double-wall stove pipe) in the main salon to keep the main deck nice and toasty, here are things we employ each winter to keep our entire home warm, dry and comfortable. In no particular order...

1. 2 household size dehumidifiers fore and aft. We typically run one at a time, but only for 4-5 hours. We TRY to run one daily, but don't always. They remove an AMAZING amount of water from the air.

Darren, what brand are these and where did you get them? The ones we are using aren't nearly as effective.
 
Darren, what brand are these and where did you get them? The ones we are using aren't nearly as effective.

Frigidaire 30 pint per day unit is what I use.
 
Bite the bullet and buy a household dehumidifier.

You will be very pleased with the results.
 
Caframo stor-dry in the head. Eva-dry in the galley. Oil-pan heater. Hatches cracked. I agree with Sabre602. Read a book about it years ago, in which the author uses smoke to watch the airflow.

The eva-dry works well until it freezes up. Can even keep the glass condensation free on the occasion that I sleep onboard, in harbour, in the winter.



NS is correct, if they get too cold they can freeze up. I keep a little heat in the boat so most of the time the boat stays in the 40s during the day in the cold winter months. However, too long of being too cold and they will freeze up. Not a problem as when it warms up, they thaw out and start working again.
 
4. H2Out Space Dryers. We have 15 of various sizes placed throughout the boat (we sell them in our online store). Keeps moisture out of lockers and cabinets. And they're infinitely reusable.

.

I'm not a scientist but I don't understand how they work or would work. It would seem to me that the most water they could remove would be what they could hold. Otherwise, they may move a little around but that's all I could see. Guess my question is if they dry things out, then where does the water go?
 
We have space ship fans in the Engine Room and V-birth. Since cold moist air sinks we keep a dehumidifier in the head and put the drain hose in the sink. We also keep the hot water tank on to help keep the Engine Room warm. As has been stated air movement is the key.
 
We use this one. Got it from the big orange box store.
 

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