Winter On Board

[CaptTom]

I think it's time to review some facts about electric heaters. All electric heaters are 100% efficient. That is, ALL of the electricity consumed is converted to heat. Heat is the movement of air molecules. Electric heat does not come in "wet" or "dry" flavors. It's just heat. So buy a $1,500 imitation Amish fireplace, a $50 ceramic heater, or a $14.96 Wal-Mart box heater. They'll all put out the same amount of heat, for the same cost in electricity. The oil filled heater, as Dockhead points out, is just doing an extra step of transferring the heat to a liquid, so it radiates out into the room more slowly. They're also quieter, since they have no fan.

An average US household AC outlet is rated for 15 Amps. Watts = Amps x Volts. 120 x 15 = 1,800. You don't want to max the circuit out with just one appliance, so you'll find that virtually all plug-in electric heaters produce 1,500 Watts on "high".

If you have 30A service to your boat, you'll only be able to run two of these. 50A and you should be able to run three. In either case, they must be on separate circuit breakers.

For reference, 1,000 Watts = 3,413 BTUs. 1.5 x 3413 = 5,119.5 BTUs from one heater, or just over 10,000 BTU running two.

There are lots of factors to consider when calculating how many BTUs you need. On most cruising-size boats, you won't get by in real winter weather with only 10,000 BTU. Maybe in a mild climate; you'd have to check the figures for your location.

[Suijin]

Originally Posted by CaptTom

An average US household AC outlet is rated for 15 Amps. Watts = Amps x Volts. 120 x 15 = 1,800. You don't want to max the circuit out with just one appliance, so you'll find that virtually all plug-in electric heaters produce 1,500 Watts on "high".

If you have 30A service to your boat, you'll only be able to run two of these. 50A and you should be able to run three. In either case, they must be on separate circuit breakers.

For reference, 1,000 Watts = 3,413 BTUs. 1.5 x 3413 = 5,119.5 BTUs from one heater, or just over 10,000 BTU running two.

If you live in an area where electric heaters are going to have to run a lot to keep the boat comfortable, it's a VERY good idea to run a separate power cord to your boat instead of running them off your in-boat 120v wiring. It's safer as you don't heat up/overload your wires in the boat.

[Tantalus]

Get an electric blanket

[Whispering Star]

We have spent sometime in the cold weather regions, we have a heating system on our boat too, it would warm the boat from about the waste up. (yes, we used fans to circulate the air) but our feet and legs were always cold. We tried different kind of heaters. But what I found is with the boat in the water our bildge was ice cold I put a small heater in there and that solved our problem, I know it's wrong but I put an electric blanket on the sole (it was brand new and we didn't walk on it or put it on a high setting And it was toasty in the cabin on the cold winter nights.

[jkindredpdx]

I don't think the Op said what kind of boat they are planning to live-aboard. A drafty boat, like a drafty house, is going to feel cold and miserable. A fully enclosed cockpit really helps.

My boat has a thick fiberglass hull lined with mahogany and ~1.5" foam sandwich cabin. I close off the vberth from the saloon, have a runner on the sole, and use a small computer fan to circulate the air. I wear slippers, sometimes a cap, and keep a couple lap blankets around.

I keep the temperature in the saloon reasonably constant cuz I figure it is more efficient and comfortable to maintain rather than heat up a cold space. In my mountain cabin it takes a 1/2 day longer to warm up the floor, walls, and furniture than the air.

[Cheechako]

a small electric heater will serve you well. Turn it down when not on the boat. IF on high a lot, it may destroy the 30 amp AC cord in one season. (usually at the boat connection end). But worth it for the ease of use.
The bunk you sleep on will become saturated under the mattress and wet. Try putting something under there to allow circulation. The Dri-Dek product works well, but has gotten awful expensive. Even some Vynil or cedar lattice from Lowes might serve you well.
The heat in a boat tends to rise to the top of the cabin, so much so that you can tell when you stand up! Feet are cold and ears are hot! Some people use a fan for circulation... if so you need a real slow moving type.

[rw58ph]

It would help if we knew that size and kind of boat as that will be a big factor.

Staying dry/condensation may be more of a problem than heat. Keeping the entire boat dry, free of moisture in the air and condensation is a constant battle for small boats that are closed up. AC dock power may also be a concern. The limitations is the boats wiring, the dock wiring and the marina over all availability, which are not easily changed. 30 amps is like three high amp items, heaters, water heater, charger, micro wave, stove etc. Water and sanitation might also be a concern, so the slip and marina are major factors as you will proable have to rely on the marina facilities for laundry, showers, restroom etc. On a boat almost everything thing has is limited and has to be managed.

We been a live aboard for 16+ years, and we have seen hundred of want be living a boards come and go. Most do not make it though the first years, especially small boats and or boat not live aboard ready. So make sure you talk to the live a boards in your area so you know/understand what it takes to be a live aboard.

Lastly many marines do not allow live aboard and/or have long waiting lists so talk to the marinas. There is a reason that a very very small % are live aboard year around.

[PUDDLE JUMPER II]

What is the best brand of Marine Dehumidifier on the market today that is NOT diamond studded... lol....