Condensation in a locker

[snooks]

Can anyone think of a solution to my problem.

Underneath the seat to our chart table at the head of our pilot berth, sits our calorifier, which is heated by the RAW water from the engine, it gets nice and warm. Also in this locker is the heating duct that goes into the saloon, and also disappears off to the forecabin. Consequently this locker gets warm. I plan to insulate the heating ducting but the locker will still get a lot warmer than the hull which runs the full height of the locker.

The problem I have, is that hull is cold, the air is warm and loads of condensation runs down to the lowest point of the locker.

With this happening as soon as we go sailing and heel over the water that has formed runs around in the locker and if we are on a port tack for any time this water then seeps under the floor board under the nav table and the water goes into our spotless dry bilge, making the bilge and the floor wet, and anything that falls on the floor (usually the log book after a few tacks) gets wet as well.

I don't really want to drill limber holes from the locker to the bilge, so can anyone suggest any other alternatives. The locker is just the right size for all my tool boxes, and I don't want to loose any of the stowage.

Cheers

 

[Seajet]

Not quite sure if it would suit, but some of my lockers are lined with thin 'Floatex' waterproof carpet, which keeps them very dry and the best lockers on the boat for valuables; might need to go up your ( inner ! ) hull side too though ?

 

[Orla]

Hi Snooks

Insulate the the hull with karri mat type foam, got mine through Cali marina inverness, they use it on there charter boats.
We have almost 100% coverage now and no condensation at all.
Give the hull a good clean, cut the foam to the size required and glue it down.
Transformed our boat when the weather gets cold...

Doug

 

[Coaster]

The amount of water vapour (i.e. water in gaseous form) air can contain is proportional to temperature. Condensation develops when the air temperature falls below a certain level ( the "dew point"). This level depends on the amount of water vapour in the air. When the temperature falls too low moisture is precipitated out onto a suitable cool surface or, if none is available, onto dust particles in the air (making fog or steam).

So to avoid condensation you must either prevent the temperature getting too low or prevent the air having too much misture vapour.

Option 1 is to insulate inside the locker, bringing surface temperature up above the dew point.

Option 2 is to seal the locker, preventing moisture laden air entering from the saloon, and removing moisture from the air in the locker using packets of hygroscopic salts or otherwise. This option will only work well if the locker is rarely opened.

 

[VicS]

If this locker suffers from more condensation than other unlined lockers against the hull side there must be more water vapour in there than in the other lockers.

Are you sure you do not have any small leaks from any of the systems in there that could cause this ? Or is this condensation occurring because the space is open to the cabin?

 

[johnphilip]

suspicious

Are you sure this is all condensation?. Many calorifiers have a pressure relief valve which drips as the water in the calorifier warms up and expands. The only way is to arrange some drip bowl or lead off from the valve. In theory turning off the domestic pump and leaving a tap open will prevent it happening, but who is so organised they remember to do this every time they start the engine in a hurry?

 

[charles_reed]

Are you sure this is all condensation?. Many calorifiers have a pressure relief valve which drips as the water in the calorifier warms up and expands. The only way is to arrange some drip bowl or lead off from the valve. In theory turning off the domestic pump and leaving a tap open will prevent it happening, but who is so organised they remember to do this every time they start the engine in a hurry?

excuse the thread drift but

I had the hot-water pipe under the sink burst, flooding (very expensively) the fridge compressor controls.

On that occasion the pressure relief valve, on the calorifier, had omitted to open.

 

[johnphilip]

excuse the thread drift but

I had the hot-water pipe under the sink burst, flooding (very expensively) the fridge compressor controls.
On that occasion the pressure relief valve, on the calorifier, had omitted to open.

Thank-you that rather proves my point that the calorifier should be dripping unless you want a burst as you describe, the "Quick" brand one on my boat certainly does and it is quite a nuisance, but necessary as you have proved.

 

[Coaster]

On the topic of the calorifier pressure relief system, we used to have a problem of water dripping into the bilge below. I solved this by fitting a clear plastic reinforced hose to the valve and routed it to a new skin fitting high up on the hull side, immediately below the rubbing strake. The pipe is taken up as high as possible, internally, so that the last part drains. The rest has standing water in it which I'd rather avoid but seems a lesser evil than dripping into the bilge frequently.

 

[Csail]

Nappies?

 

[vyv_cox]

If condensation is the source of the problem, rather than leaks, then a durable and effective cure is cork tiles. The books in the locker adjacent to my chart table suffered a little from dampness that was solved in this way. They are available self-adhesive or with separate glue, plain or sealed with a lacquer.

 

[pete]

Are you sure it is only condensation ? there must be quite a lot to be running around the cabin sole.
If it is I would go for insulation on the hull and high and low level vents in the locker with a small fan to keep the warm moist air moving works in most bath/shower rooms.
Pete

 

[Bosun Higgs]

If this locker suffers from more condensation than other unlined lockers against the hull side there must be more water vapour in there than in the other lockers.

Are you sure you do not have any small leaks from any of the systems in there that could cause this ? Or is this condensation occurring because the space is open to the cabin?

Just what I was going to say.

Most calorifiers have a pressure release valve - the water inside them expands as it heats up and the one way valve on the pump plus the valve on the taps stop this going anywhere so there is a valve set at a pressure below the pump pressure which voids water into the bilges. Or in your case the bottom of the cupboard.

 

[snooks]

Most, if not all, of it is condensation, it's clearly visible on the hull and running down it (all of which is below the waterline) may be the calorifier vent is letting out a bit of water and that's where the moisture in the air is coming from.