How much winter heat?

[bendyone]

Am keeping afloat this winter, in order to keep the inside dry eyc how much background heat (in watts please) do I need.
My thoughts are 60w heater under the engine and 300w tube in the main cabin.
Do I need to consider a dehumidifer? ( horror stories about fires) The boat is left about a month at a time. Running costs are not important as free electrictiy.
Hunter 26 Horizon.

 

[tobble]

I'm keeping an eye on a neighbour (a fellow liveabord) 's boat while he's away for three months. He has just a dehumidifier, which keeps the place both warm and dry; as the power used by the unit (or any appliance) is ultimately disapated as heat, you have botha de humidifier and 100 or however many watts of heat.

There is one horror story of dehumidifiers that I am aware of, albeit a rather spectacular one! any mains appliance has the potential to cause a fire, just make sure the whole system is in good order and the chances of disaster are very small indeed...

 

[savageseadog]

I have found that dehumidifiers won't work at very low ambient temperature. I will be trying to use an external temperature sensor next time I use one.

 

[BlueChip]

With free electricity its a temptation to over heat and dry the boat over the winter. If you go too far its quite possible, to dry the woodwork to such an extent that the joints open and cracks appear. This happened to me some years ago.
I would suggest a 1KW oil filled radiator with a thermostat set at about 12 degrees and a dehumidifier which if it has a humidistat is set to no more than the medium position, if you have a hygrometer you can monitor whether this is the right setting. Depened whether you are in or out of the water. If you are on the hard then you will need more heat.
We also use a desk fan on a time switch set to come on for 30 minutes three or four times a day to get the air inside the boat and the lockers circulating

We pay for electricity and our winter regime is a 300w tube in the saloon and a 60 w tube in the engine compartment and a dehumidifer on a time clock in the saloon.
The heater tubes are on a greenhouse froststat and only come on when the temperature is less than 5 degrees. The dehumidifier goes on in December, for 8 hours a day 10 - 6pm 7 days for 2 weeks then we reduce this to 4 hours a day for 7 days, then 4 hours every other day.
This seems to work ok for minimal electricity cost.

 

[eastcoastbernie]

When I leave my boat in the water I leave a tubular heater on board. About 100 watt I think ... not much more than a light bulb when you come to think of it. Anyway, I think it probably depends on the size of the boat, mine's just 26 ft and the tubular heater keeps the frost off. When I visit it during the winter, the inside of the boat actually feels warm! I wish I could heat my house so easily and cheaply. I leave the doors open so the heat can circulate and drain the water tank. I leave the engine unwinterised so I can go sailing if the weather's nice. Run the engine every once in a while to warm it up and keep the batteries charged.

No sign of any damp in the boat.

 

[Boathook]

I don't bother with heat when not on board. Have found that ventalation is the main thing thing. Boat does get slightly damp but once back on board bunk cushions only take half day to feel dry and even less when ashore !

 

[Searush]

Always left afloat without heat (swinging mooring) just make sure you have loads of ventilation and all doors/ hatches are open. May need a wipe down with a disinfectant if any surfaces have been left salty as this seems to feed the moulds.