5 Ways to Heat Your Boat

November 10, 2014


5 Ways to Heat Your Boat

5 Ways to Heat Your Boat


5 Ways to Heat Your Boat

Cooling temperatures can keep you off the water, but adding a cabin heater can warm your cabin and heat up your next boat party. There are many ways of heating your boat, lets explore some of the more popular methods of staying warm that can keep you on the water all winter long.

1. AC Heaters

One of the simplest methods is to use an AC electric heater plugged into the boat’s AC electrical system. Many models are available, but heaters designed for a marine environment are usually preferable. Electric heaters designed for the marine market are usually made of stainless steel and/or other materials that resist the corrosive marine environment. They should have some sort of safety switch that will turn off the heater if it is tipped over. Some models are ignition protected, meaning that they are safe in gas-powered boat engine rooms. Models without ignition protection certification should not be used in areas where gasoline fumes are present, for obvious reasons. Electric heaters are best suited to boats that either have an AC generator or are usually at the dock where shore power is available. It is not practical to run an electric heater through your inverter, as it will draw the battery bank down too quickly.

2. Fuel Burning Heaters

Fuel burning heaters are among the most popular. Diesel heaters are commonly used with boats that use diesel fuel for propulsion engines as they have a ready source of fuel for the stove. They are available as bulkhead mount as well as floor mount, and may or may not have a fan to circulate the warmed air. All require a flue (stovepipe) that exits the cabin of your boat to dispose of the exhaust. Some heaters use natural convective draft, while others use fan-assisted draft to assist the removal of the toxic exhaust. Some of these heaters have a window, which allows you to enjoy the sight of the burning fire inside the stove. Propane (LPG) space heaters are available with “direct-vent” through fitting and flue cap, where the combustion process is completely isolated from the inside of the boat. Some of the better designs have an oxygen sensor, which will shut off the fuel supply if the oxygen in the cabin reaches a dangerously low level. A few solid fuel heaters burn charcoal briquettes or wood. These also require a ducted flue or stovepipe, as well as a source of wood or charcoal. In the past, coal was used, but modern solid fuel heaters are not designed for coal burning, as it burns too hot.

3. Hydronic Heat

Heated water can be circulated by a pump through tubes or hoses running through the boat to small radiators (heat exchangers) located in the cabin areas that require heating. The heat from the water is transferred to the air by small fans blowing through the heat exchangers, thus heating the boat. These fans can be thermostatically operated, so you can have separate zones of heating, allowing different levels of heat in the individual cabins. The source of the heated water can be from your main engine cooling system, heating coils installed in diesel or propane stoves or ranges, or it can come from your domestic water heater via heat exchangers installed in the water heater. Most marine water heater manufacturers offer optional heat exchanger loops in the water heater, allowing you to heat your galley and head domestic water from the engine, or the heating of water for space heating with the above-mentioned fans/heat exchangers. Multiple zones also are a feature of this type of heating, but add to the complexity and cost of the system. An added benefit is that the bilges, lockers and stowage areas that the hose or tubing runs through will be warmed and de-humidified, decreasing mold and odors common in the colder months.

Hydronic furnaces, which use diesel or kerosene fuel to heat water that is pumped throughout the boat in the same manner as the engine/water heater/radiator system described above. These heaters usually require less maintenance than the forced air furnaces, as the thermal cycling is not as extreme. These types of heaters have a delay between the starting of the heater and when you begin feeling the warming of the cabin, because the water takes some time to heat and circulate out to the heat exchangers and fan that will be warming the air. This hydronic method has many optional ways of connecting to other components, allowing the furnace to serve multiple heating purposes.

4. Forced Air Furnaces

There are several makes and models of forced air furnaces available. These heaters burn diesel or kerosene fuel, exhaust fumes are ducted overboard, and the heated air forced through ducts installed in the boat to distribute the heat. These require rather large ducting in the boat from the heater to the areas of the boat that require the heat. You will feel nearly immediate heat output once the furnace is started.

5. Head South

One other method should be mentioned, and that is to point the boat south, and keep going until it gets warm enough to sit on the deck in your swim suit. If you live in the cold northern climes you may even get a few extra willing crew members to come along for the voyage.

Whatever way you go, keeping your cabin cozy can keep you out on the water even when it’s cold outside.  Even the most thin-skinned companions may be persuaded to go out with a toasty heater onboard.