Heater of dehumidifier left on a yacht??

GBowerman

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I have heard that leaving a dehumidifer on a yacht can overdry all the wood on board and that it might be better to leave a small heater on instead - any thoughts or ideas or experience you might like to share on this matter? I do have access to shore power.
 

tcm

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i have left dehum on all the time on wood-interior boats and never ever come close to "over-drying" it nor any such effects of wood cracking.

But the issue might be one of lack of air movement - so a good idea which i used was a fan (or fan heater set to "just fan" and NOT heater) blowing thru a £20 b=Q heater, which gets some air moving around - AND a dehum. Put these on a timer to kick in just few hours from 3am to 6am if shorepower is metred.

On the uk south coast, airtemps can get low but not often TOO low so all the doors open to all cabins, dehum at lowest point. Dehum most important this time of year, heater not so much.

Close the boat, and keep light out with cardboard up against the windows - not the curtains as this will encourage condensation on the cooled curtains, leading to mildew. Items with low specific heat capacity (fabric, mattresses) against those with high can expect big temp difference and any condensation on one will lead to damp on the other - followed by mildew. So turn matresses to lean vertaically, and sit them on lumps of polystyrene or balanced on bit of wood to keep them high in the boat, and off the cold things

As far as poss, all linen and fabric should be off the boat, or not exposed to air (roll up the bedding tight and put in a plastic bag) and then all jammed into a cuboard or shelf high up in the boat.
 

Cantata

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Last winter I did none of those things, I simply left a hatch cracked open aft, providing circulation via the dorade vents forward. Boat was well aired all winter, no damp, no mildew, no smells, and we even left all the cushions on board. Having thought long and hard about a heater and/or dehumidifier, I'm glad I didn't bother.
 

tcm

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Re: qualification of dehum/heater

ok, in a straight wooden yacht 10years old already I am not sure of the need. I spose i had in mind boats with much more fabric inside, and with more items which might not be marinised, or marin grade.
 

Ric

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I leave a small oil radiator and dehumidifier on my boat all winter. It has never done any harm. The benefits are nice dry bilges, can leave bedding on board, electronics do not suffer, no mildew.
 

compie1

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I have a delonghi dehumidifier/heater DEC 21 great product because if it gets to cold <8°C dew point is not ok for dehumidifier so the combination of both works very good. This is one of the best buys i ever made to keep it dry and clean on board. it also keeps the boat frostfree in the winter /forums/images/graemlins/laugh.gif

would do it again
 

Gordonmc

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There was a thread some time ago about a boat whose planks separated through over enthusiastic heating/dehumidification. I think this must have been an extreme, though. My wooden boat always has an inch or two of water in the bilge but with ventilation there's no real problem... until there's a frost. This year I put an oil filled tube heater and a B&Q dehumidifier in (boat in water) and it made a real difference.
Even on the coldest mornings there was a no condensation on the saloon ceiling and the bunks were dry.
Now its a bit warmer the electrics are back in the garage.
The moral from this ramble is that heat and dehumidifiers have their place, but use judiciously.
 
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