For most sailors, winter is the end of the boating season. They put the boat into storage and go back to routine life on land for some time. But, for liveaboards, winter doesn’t mean that they will stop sailing or live on their boat. Living aboard your boat has many advantages and also disadvantages, as most things in life. The most important thing about living aboard is that you live closer to nature, avoid routine life, and learn to live independently. So, as for heating systems, boats can have a variety of them. For example, diesel heaters in the main cabin are piped into the fuel system. Or, central air conditioning with a compressor and air handler.

What is the Best Ways to Heat a Liveaboard Sailboat? In this article, I’m going to give you some information about these systems and finally come to the conclusion for which one is the best. Follow me!

Useful Information about Boat Heating Systems

Winter sailing is still a challenge for most sailors due to the more extreme weather conditions, which necessitates more preparation. Fortunately, there are many types of boat cabin heaters available that can make winter sailing more enjoyable by keeping the interior of the sailboat warm and comfortable.

As aforementioned, there are many ways that you can use order to warm the interior of your boat. These are engine heaters, electric heaters, hydronic systems, heating stoves, forced-air systems to reverse-cycle air condition systems. As you see there are numerous choices and for every budget. It’s important to note that these systems work in a different way but their function is the same. Meaning that they can use fuel or other forms of energy so as to create heat that will be therefore spread in the boat.

There are sailboats that use diesel heaters or electric heaters. Some vessels have “core” air conditioning. This means that the compressor and air handler are hidden and cold air is forced into ducts in the boat. These systems typically run on “raw water”. You can easily spot these vessels by the steady stream of water discharged overboard when their air conditioners are turned on. But, for this kind of system, you have to regularly clean the raw water filter of debris that will get from the outside water.

Others want to choose the more budget option and choose to buy a portable electric floor heater. These can work fine as well and can be stashed away in a locker when not needed. Others go for the simple option of buying a wood-burning fireplace. But, some of these cheap systems can cause problems when used in the boat and you have to be very cautious in order to avoid any unexpected incident. Let’s now see the most common heating systems for boats!

Diesel Stoves and Ranges

In case you want to invest in a good heating system and you’re not low on budget, then a Canada-made Dickinson Newport diesel stove is an excellent small boat heater. This is great as it can spread heat throughout a small vessel, until a 36 footer, in cold locations. The stoves from Canada are costly, but they are extremely reliable. A stove fan helps as this stove is small, and it’s right on the nose of what’s useful in freezing places; this is a Peltier-effect self-powered fan that blows the hot air around the cabin.

Dickinson also manufactures diesel cooking ranges and stoves which have better performance but are much bigger. As a result, this heating system will need a good chimney length, approximately 5 inches. The stainless steel flue pipe (which turns blue/gold at the bottom) provides a lot of heat, so if you shorten it, the stove loses a lot of its power. The stoves themselves are not hot, except at the top; halfway down, you can place your hand on the side of the stove. Bear in mind that the top plate and the chimney provide the heat.

Other models like the Newport use about 1.25 gallons per 24 hours when you set it at a low level. Other and bigger models which are all cooking ranges will need a couple of liters or more per day. So, we’re talking about 45 liters of diesel a week as a minimum, for 24/7 use. The Refleks, a Danish fishing boat diesel stove, is suitable for larger vessels. It produces more power but needs an 8 inches chimney. As a result, it consumes more diesel. Note that the chimney is an essential component of all diesel stoves.

>>Also Read: Best Boat Heaters

Diesel Blower Heaters

One of the best diesel blower heaters nowadays is the Chinese copies of the Eberspacher diesel hot air blower, also known as a ‘diesel parking heater’. For a 40-foot boat or larger this heater will work perfectly if it’s well insulated and when you use it at low temperatures. Prefer the 5kW version for larger boats and the 3kW for small boats. Keep in mind that they aren’t the same as each power size has a different size heater body. Furthermore, note that you have to buy the expensive version (around $250) as cheaper models tend to have missing parts, like the exhaust pipe surface mount plate. And note that these heaters don’t compare to a Dickinson stove but if you’re on a budget $250 is different than paying $1,500. There are some options on Amazon too.

Traditional Stoves

Heating stoves are still one of the most common ways to heat a sailboat, despite the fact that they’ve been around for centuries. They can use liquid fuels like kerosene, diesel, and propane, as well as solid fuels like charcoal or wood. Some heating stove systems use a direct draft system, in which fresh air is pumped through a fan. But others use a natural draft system. In this system, the air is pumped through the combustion procedure naturally.

Bear in mind that a heating stove should be in the saloon so as to radiate heat and efficiently circulate hot air. In addition, a reliable heating stove must have a damper to help in controlling the airflow. Also, an exhaust pipe is particularly important in order to withdraw the exhaust gases resulting from the combustion.

Note that most heating stoves do not use electricity. However, a heating stove with a BTU production of 7,000 to 9,700 should suffice, especially if it uses one pound of propane in about 5.5 hours. Wood or coal stoves seem to be a good idea at first as they’re cheap and powerful, around 5 or 7kW is typical. But, the amount of fuel you have to transport is too much. They’re good options only in case you have a barge because you will have enough stowage space.

Even for a 24′ boat, never buy something with less than 3kW of output as they won’t heat the cabin at all. Stoves on a liveaboard boat should usually be 5kW and they always have to be turned down. It is impossible to have too much heat, but it is possible to have too little.

Electric Heaters

If you have shore electricity, you can use all-electric or a combination of mains power and onboard heating. This would be determined by the cost per kW of your local power unit versus the cost of onboard fuel. Halogen bar fires and 500W PTC micro fan heaters are the cheapest electric heaters in terms of heat output versus cost per kW. But, they both produce smaller output, therefore you’ll need a 2kW convector or a 3kW fan heater in case you’re all-electric.

However, this option can be good if you’re sailing occasionally and not for living aboard. Electric heaters work similarly to standard home air conditioners and are usually powered by 12-volt electricity. They’re installed inside the cabin and heat the coils with electricity by the boat’s batteries. A fan draws air over the coils, which heat it up before being blown into the boat’s interior by another fan. The main disadvantage of electrical heaters is that it needs electricity, limiting your ability to travel far from the sea. This is because you’ll need to recharge the batteries from time to time, and this will easily deplete them. Check some boat heaters on Amazon here.

Halogen Bar Fires

These systems include some 400W tubes and heat directly through radiation. What they exactly do is that they don’t heat the air but they heat you. Meaning that they have small output if you use them as freestanding heaters or wall-mount heaters. However, when sitting in front of it then it will excessively heat you up. It is energy efficient in this regard since the same effect from a fan or convector heating the air will need 2 or 3KW versus the 400W or 400W x2 that one of these halogen heaters provides.

Halogen heaters come in 3 or 4 bar versions. You can use one bar at a time because it’s sufficient, and maybe two bars for 5 minutes when returning to the boat; it will be really hot! It’s worth mentioning that after a few months, the tubes will fail, so finding another one to replace is crucial. So, you shouldn’t use more than one tube at a time; and by the time it won’t work anymore, you can switch to another tube.

Bear in mind that running three bars on these heaters will be very dangerous and not good for the system. This is because the local heat is so intense that the tubes will get damaged faster, and the control panel switches are going to melt. So, this is really dangerous and you should only run it with one bar hot, or two at most.

Micro 500W Blowers

These small PTC ceramic element fan heaters are great for overnight heating or direct heating. This is because they blow directly onto the person. They generate a lot of heat for their size and power draw: roughly twice as much as you’d expect from a half-kilowatt. A standard fan or convector heater will probably provide around a 1kW equivalent. They are also cheap to purchase at around $30.

There are models, like Nexgadget, that are really energy-efficient fan heaters. However, most of them come at 600W. If there were 1kW or 2kW versions, they would generate twice as much heat as a normal fan or convector, or similar to it. At 0.5kW, each of these produces roughly the same amount of heat as a normal 1kW fan heater or convector heater.

Engine Heat

This heating system works by transferring heat from the engine’s heated coolant fluid to the cabin of your boat. Note that the coolant lines from the engine to the heat exchanger should be planned accordingly. There should also be a fan that heats the cabin air by blowing it into the heat exchanger. Several hoses will then be used to pump the hot air into the boat’s interior.

It is beneficial to use this system because it is quiet and relies on the engine’s close-circuit cooling system, which eliminates the need for radiators or external water pipes. However, the system works while the engine is running, and it can be very costly in terms of additional engine maintenance and fuel consumption.

Dehumidifiers

A dehumidifier can work really well as some of the cold you feel in the boat is because of the dampness. There are some modern models that are half the weight of the old compressor version and can work just well in cold temperatures. Desiccant dehumidifiers that run on mains electricity are the most modern kind. They use about 300 watts of power to extract liters of water from the air every day. And this is their main disadvantage as they use an excessive amount of water to function. You may either continue to refill the tank or pipe the water to a sink drain or somewhere else.

But, dehumidifiers can dry the boat out excellently. They just need too much water which is impractical for long voyages and also bad for the environment. A good dehumidifier can take the humidity down so low at 30%, but this will be bad for the throat. So, you have to set it at around 50% or 60% where humidity levels will be more comfortable. Like this, all the damp will be gone from everywhere including under mattresses, lockers, etc, and thus no more mold or drips.

Hydronic Systems

These systems work on the same principles as traditional hot water heaters. It is based on the circulation of heated fluid through a tube to radiators or fan units that warm the air. Although these tubes should run the length of the sailboat, the fan units or radiators can be divided according to the series of zones the boat has.

A hydronic system is typically smaller than a water heater, but it can also be used as a portable water heater for the boat, especially if you need hot water. It’s usually found in the engine room of a boat and can disperse heat with the help of a coolant. It can run on either the vessel’s main fuel tank or a separate fuel tank.

Hydronic heaters use electricity in order to power the system’s coolant pump, a fan for combustion and a fuel-metering pump. During the first half-hour of service, they use the most power to heat up the coolant. Once the boat is hot, the energy demand drops dramatically, and the system’s job is reduced to maintaining cabin temperature.

The key benefit of a system device is that it reduces moisture in the boat by eliminating cold spots. The maximum performance of a suitable hydronic device should be 25,000 BTUs per hour, with a power consumption of 6 amps and a fuel consumption of 0.22 gallons per hour.

Forced-Air Systems

A forced hot-air system works on the following principle. A heater heats air by burning diesel, which is then forced through ducts to louvered vents in the boat’s interior. Ducts are usually hidden behind panels and cabinets. The engine room houses the majority of forced-air heaters. And, there’s also a series of seals and exhaust pipes leading to the stern, where combustion exhaust is discharged.

The system can be switched on manually or through its thermostat. This allows for air and fuel to be drawn into the combustion chamber and ignited under a controlled flame. The heated air is then pushed into the vent and distributed across the cabin of the ships.

Forced-air systems are easier to install than hydronic systems, cost less than other heating solutions, and account for roughly 75% of the marine heating industry. The ducts behind cabinets and panels often radiate heat, which is one of the many advantages of a forced-air system. Bear in mind that Webasto’s Air Top 5500 generates 5,000 to 17,000 BTUs per hour. It also uses 0.04 to 0.16 gallons of fuel and 1.2 to 8 amps of energy per hour.

Reverse-Cycle Air-Conditioning Systems

The operation of a reverse cycle air conditioner differs significantly from that of a traditional gas or portable electric heater. Meaning that conventional heaters have to create energy but a reverse cycle system absorbs heat from the outside air to warm the air inside, which is a more energy-efficient method.

When in heating mode, the system operates in the opposite direction of cooling. It basically draws heat from the outside air before spreading it across the boat. To get technical, a refrigerant is passed through an external coil, which absorbs heat from the surrounding air. This refrigerant is then pumped into a fan coil device within the boat, where it releases heat into the interior. The system can perform this even in freezing conditions so it doesn’t have to be warm outside.

A successful reverse cycle air conditioner would have an automatic defrost cycle. This results in a more efficient operation, as it was designed with cold weather in mind. So, even if the temperature drops to minus 15 degrees Celsius, your reverse cycle air conditioner will keep the boat warm.

This heat pump operates in the reverse cycle, much like a regular household heat pump. They’re usually very pricey, but they’re a great way for liveaboards during the winter, particularly if you want to circumnavigate the globe.

What’s more, is that this system emits only one-third of the greenhouse gas emissions of standard electric heaters. Some reverse cycle units with energy ratings higher than 5 stars, emit less than a fifth of the emissions generated by traditional electric heaters. An example of these is Daikin’s only 7-star energy-rated split system* (US7). And, there are more split systems nowadays that use the new R32 refrigerant. This has 66% lower global warming potential factor than R410A which is the common refrigerant type. So, let’s heat our boat but let’s also be responsible. Less greenhouse gas emissions equal a happier planet!

The Bottom Line

So, we’ve come to the end! These are all options from which you can choose to heat your boat while living aboard. Keep in mind that there’s probably no “best way” as it mostly depends on the type and size of your boat, the locations you’re sailing to, and your crew’s needs. Many sailors use an electric heater from West Marine when inshore power. Others prefer the Dickinson marine heater to achieve better results. In my opinion, if you liveaboard and also sailing during the winter, the best way to heat a sailboat is to install a heating system, like the reverse-cycle air-conditioning systems. They can be expensive, but you just pay once, you go green, and heat your boat safely and in a durable way. Hope that this article will help you make the right choice!