The Best Marine Air Conditioners

Boaters and fishers can easily come up with a list of things that make a mariner’s life enjoyable. However, only a few would remember to include a sailboat air conditioner in the list. Knowing the immense, even life-saving benefits of these appliances, it’s time we give them the recognition they deserve.

After all, the best marine air conditioner not only beats fluctuating temperatures that the average sailor puts up with, it also keeps your vessel in tip-top shape and guarantees that you can lounge comfortably even during humid August or chilling November days out at sea or in the dock.

It’s not so much a luxury as a necessity, in short. And do you know what truly separates the best from the rest? Like most of the selections here, they don’t have to eat up your boat’s power to ensure optimal air conditioning.

Top 9 Marine Air Conditioner Reviews

1. Webasto 5011396A AC Retrofit Kit

Virtually noise-free, well-constructed, and economical, this Webasto AC for boats is a popular recommendation in the sailing circles. It’s hard to not start this list with the brand that continues to be crowned as the “top-rated boat air conditioner brand” in recent years.

I instantly fell in love with the promptly noticeable quiet operation of this AC, and this comes from someone who has had his fair share of noisy, sleep-disturbing air conditioners. I’m always willing to take that over power-saving, considering how often I rely on my sailboat’s AC.

It took me around 2 hours to install, which is relatively fast as far as any boat AC system goes. I consider myself lucky for not needing to make any adjustments to my boat to accommodate its shape. I credit the detailed instructions and materials provided for the hassle-free installation.

The first trip I took with it was to the Caribbean where it kept the heat at bay for a good 2 weeks. It’s great but not that exceptional compared to others. I haven’t tested the heating feature yet since I frequently go to hot fishing and cruising venues with my sailboat.

2. MarinAire MSBA16K2 Air Conditioner

This unit’s undeniable strengths are that it’s relatively easier to install than most marine ACs, cools amazingly every time, and has some neat additional features.

It cools like a top-tier AC for sailboats that are on the medium-sized side. I once took on a 95-degree day with over 90% humidity with this seamlessly cooling champ, and the best way to describe it is as ‘ice-cold freshness’. This is why I would be a tad hesitant to shift any time soon to another sailboat air conditioner in the cabin of my 42-foot sailboat.

It’s almost elementary when it comes to installation, too. Every electrical hookup is marked well and the instructions made everything straightforward. The control board along with its box mounts independently from the unit. It made wiring relatively uncomplicated and left me with better freedom to decide on the best place for mounting.

I don’t really notice any significant power-savings despite the brand’s claim. They’re probably marginal at best, but I do have to admit that I tend to operate it in high settings. What I do love is that it’s quieter than most other units.

The pressure gauges are nice to have. They helped me figure out how to optimize setting up the AC and even helped me decide where to place the remote temp sensor.

3. CAMPELIFY Air Conditioning Systems

This marine air conditioning system is versatile for a number of good reasons. Taking into account its price and pros, it becomes obvious that it beats many of its competitors.

Considering its mild cooling capability, minimal weight, and compact size, this unit is a good fit with the small cabin of my Caraway that I got for a good bargain. Despite its small size, it’s an efficient self-contained unit that works once you hook it up to any 12V, 24V, or 48V battery if you plan to buy those options.

I paired it with a number of 12V batteries and can attest that it’s not at all picky in that regard. With its advantage of working out-of-the-box, it’s miles ahead in terms of ease of use and installation. Not surprising for something that’s marketed as a portable cooler.

I think the cooling performance is comparatively low, but, if you keep it running at full max settings, it’s just as well because of its power-saving capabilities. I agree that this small boat air conditioner does a better job as a “spot-cooler” than a comprehensive, permanent AC.

4. Webasto FCF0012000GS AC Retrofit Unit

This AC provides real value for money through its terrific cooling power, silent operation, and ease of install.

I have two units of this on my 44-foot yacht, and I’m going to go ahead and say what I love about it. It cools just right. I hesitate to use the word “perfect” for fear of sounding biased but this is one of the few units that I’ll always look out for.

I doubt I’ll ever settle for anything less if I ever need to take a month-long trip to tropical cruising and fishing sites. It keeps my cabin and dining area cool even if it’s sweltering outside. Another thing I like is that it keeps you from putting up with the usual loud AC noises and vibrations.

The reverse heat feature gets the job done in most cases when the cool days call for warmth, but as in most ACs I’ve owned, I rarely use it. I’d rather use a separate heater than rely on it for extensive heating. Moreover, the integrated blower doesn’t deserve it at all, as it still runs even if the compressor is off. They could have made it programmable at least, considering the price.

5. Dometic 207500310 EnviroComfort Retrofit Kit

This AC is an upgrade over its predecessors, particularly in power, design, and affordability, making it a perfect retrofit option.

I’ve been meaning to replace the Mermaid AC unit installed in my 44-foot midsize cruiser. It’s one of those AC kits that are obviously made to stand out, but not much more expensive, given its spectacular specs and performance.

The cooling capacity hits the spot because I installed it in a cabin that’s just right for it. I wouldn’t expect it to perform as well in extra-hot cruising destinations, though. If you’re consistently out at sea and don’t remain docked for weeks in a tropical area, then I can safely say that it will meet your needs and perform a solid job every time.

Much like most self-contained kits, it’s one that you can install by yourself with basic plumbing and wiring skills. I appreciate the fact that they took the liberty to throw in plumbing components to make my life easier. Furthermore, you can mount the electrical box remotely, which gives you more leeway to decide the best area to install.

6. Webasto FCF0016000GS AC Retrofit Unit

This Webasto air conditioner’s superior construction readily shows what type of durability marine ACs should aim for. Once you turn it on, it proves just how much of a smooth, efficient, and consistent performer it is.

I wanted something more on the heavy-duty, hard-wearing side for my Cruisare 38, and I didn’t mind paying a hefty sum for it as long as I know I’ll get plenty of mileage. What’s good is that I got just that with this unit! It’s been 9 years since I installed it on my vessel.

I only need one unit to handle both cooling and heating for my cabin, and this has managed ambient temperatures that don’t go above 80 degrees F or lower than 50 degrees F. Simply smooth air conditioning, thanks to the high Btu and correct room size, I suppose.

The entire unit also came ready to operate out of the box. I only needed to fulfill standard ducting procedures to set it up. However, since it was a first-time AC installation, I did have to buy a separate water pump.

7. Dometic B57915.XX1C0 Brisk II

Dometic’s Brisk II has been a staple AC among RV owners due to its ever-reliable cooling capability, minimalistic design, and overall high-quality composition. It just so happens that it performs just as well in marine applications, which goes to show how versatile it is.

This is the only made-for-RVs air conditioner that made it to a list of marine air conditioners. For one, it’s made with durable materials that can handle harsh sea conditions. I can attest to this as this has been the AC system running on my 33-foot sailboat for 3 years now.

I have to admit, the ease of install was what appealed to me back when I was deciding to get this. The only real struggle was to get it on the roof of my cabin. From there, I only needed to use an electrical connection kit, which I already own, and a ceiling kit to set it up where I deemed it adequate for my boat.

It may not be much of a power-saver, but the fact that it’s a rooftop AC allowed me to overcome the dilemma of where I was going to install an air conditioner for my vessel’s rather boxy cabin. It’s a top-notch cooler as I don’t even have to set its temperatures to the extremes to get the kind of cabin comfort I want.

8. BLACK+DECKER Portable Air Conditioner

Very few portable air conditioners showcase as much versatility as this 6,000 Btu. Even fewer units can cool my mid-size cabin as efficiently as this portable, small marine air conditioner from BLACK+DECKER.

I bought this as a backup air conditioner that I can hinge on if any of my main units break down while out at sea. I always leave room for its hose and window adaptor in my vessel so it’s an easy plug-and-play setup every time. All things considered, this unit is a comfort to bring along during lengthy boating affairs.

In one of my trips to the Galapagos Islands in March 2018, the MarinAire unit of my sailboat suddenly stopped cooling, and it turned out to be a thermostat issue. Good thing I brought this superb unit with me! It was a lifesaver for the rest of the month-long trip.

It does a great job in cooling and dehumidifying, which is surprising for a portable AC that is this cheap. With regular vent cleaning and draining of the reservoir, it continues to work without hitches after 3 years of fairly regular use.

9. DOMETIC 207500316 EnviroComfort AC Retrofit

This kit offers the much-needed flexibility for retrofitting, and once it’s set up, it’s just as praiseworthy in performance and durability.

This unit has been a major part of my family’s 48-foot houseboat since 2013. It’s still going strong with regular maintenance over the years. We relied on it in almost every major sailing trip we’ve done in Asia and South America, and it never let us down unless we had to save up power and endure the heat and seldomly the cold a bit.

The first AC of the said boat only lasted for 2 years, so we had no choice but to retrofit this. It fit perfectly like the previous unit, thankfully. It didn’t hurt that the package included an in-depth retrofitting guide for the purpose. I also like the fact that the blowers support both horizontal and vertical mounting, sparing me from more thinking and needless tinkering.

I’ve only had a handful of opportunities to test the reverse cycling heating, but almost every time, it maintained the temperature we wanted. I can recall a chilly night in Caracas that forced us to switch it on, and it kept us warm all throughout. I wish I can say that it’s consistent in that regard but given the lack of opportunities I’ve gotten, I can’t say much about it yet.

How Do Marine Air Conditioners Work

To gain a good grasp of how marine ACs work, you need to learn how most refrigerant systems operate in marine package air conditioner units available in the market. Besides the chilled water type whose functionality shall be explained below, these systems typically function based on three primary components: the compressor, condenser, and evaporator.

The process starts with the evaporator collecting hot air in the room or cabin that the AC is installed in. Most evaporators come with the refrigerant whose job is to cool down the air collected. As this happens, the compressor circulates the air in the unit and maintains the flow of the refrigerant.

Then, the condenser kicks in to cool the airflow and transfer it back to the evaporator. The last step in this seamless process involves the fan and other air handlers distributing the cooled air in the room.

Besides refrigerant-based ACs, evaporative cooling systems remain a viable option for boats that need to cool a tiny area. They’re as simple in operation as they are cheap because they mostly rely on evaporating ice and a fan to keep the area cold.

Types of Marine Air Conditioners

The majority of marine air conditioners make use of a refrigerant to cool. These refrigerant boat ACs can be subdivided.

Direct Expansion Systems

Available in either self-contained or split systems, most of the air conditioning systems featured in this review falls under this group.

Seasoned boaters love the ease that these units offer in terms of installation. In addition, they are far more budget-friendly than other AC types.

With proper ducting, these AC units can cool an entire cabin or certain areas of a mid-size sailboat or yacht, particularly those that don’t go beyond 40 or 45 feet. Even so, many boat owners with larger vessels opt to rely on two or more of these units to get the cooling and heating job done.

Noise from the compressor or fan remains as one of the main downsides of direct expansion ACs. This is why brands that manufacture noiseless units are often the most coveted.

Chilled Water System

Another versatile option, these systems rely on a refrigerant to cool water. Afterwards, the chilled water is processed and transferred to air handlers that, in turn, cool key areas of the boat. I say it’s versatile because this type of system can be customized according to the specific requirements of any particular boat.

You only need to provide an area where you can house it and build the system of pumps, pipes, and air handlers. You’ll find plenty of sizable vessels adopting this setup because of its amenability to modifications and overall reliability.

Split Gas Systems

Typically found in huge vessels, these systems rely on a central condensing unit that is connected to a number of air handlers using copper wire. The wider span of these systems make them a go-to option for bigger boats, besides the fact that they normally don’t make the noise that other types of units make and don’t eat up space. Be prepared to pay more for installing these units.

Benefits and Drawbacks of a Marine Air Conditioner

It’s a given that many boaters still have reservations about getting an AC. They’re not exactly cheap, after all. Nonetheless, these units offer many advantages, let’s go over them now!

As in any kind of air conditioning for boats that you install, having a marine air conditioner imparts abundant comfort that you otherwise would not be able to enjoy while you’re out fishing or cruising.

In especially high temperatures, you will recognize the big difference that these fixed, specialized AC systems make. In most brands and units, it’s cooling that sets the bar high, that much is certain.

Furthermore, compared to window or hatch units, marine air conditioners do a better job in cooling and heating specific spots and parts of your boat. Another significant advantage is that they don’t require that much maintenance once installed properly, besides the usual strainer and air filter cleaning.

The most obvious drawback relates to cost. Most units are expensive, especially if we’re not counting the portable varieties. What makes matters worse is that, unless they’re proven energy-efficient, most ACs are power hogs. So, you have to be mindful of long-term expenses when making your decision. Even the amount of power your boat’s battery can provide should be considered, too.

One other downside, albeit arguably a minor one, involves the high Btu that most marine air conditioners have. If you have a relatively small cabin that you need to cool, you might end up with a less-than-optimal setup because your AC would more than likely waste a lot of power or even struggle to dehumidify the place.

This is why I highly encourage you to be mindful of the size of the room or space that your prospective AC will be cooling or heating.

Buying Guide

You don’t need to depart too much from the following factors to know the ideal unit for your boat. We’re going to base this guide primarily on the more modern self-contained kits and portable units featured here.

Efficiency

Efficiency in terms of cooling capacity and power draw should be one of your main concerns. After all, you might end up falling short of these units’ power requirements. You might, for instance, need to buy an extra battery bank to support their loads, especially once you’re already sailing and power is being drawn by multiple components of your boat.

There’s a good reason why marine air conditioning reviews readily reveal the Btu (British thermal units) in their list like, for example, a Dometic 16,000 btu marine air conditioner or a standard marine air conditioner 10,000 btu unit. They give you a hint of the cooling power and energy consumption. In most cases, the higher these numbers are, the higher the cooling power and power draw.

Size and Layout of Boat

Be mindful of the total area of the place you mean to cool. You need to know the exact area in cubic feet, with fixtures and structures taken out of the equation. Don’t hesitate to ask for and use the manufacturer’s recommendations when taking your measurements. They might have their own specifications and suggestions that will allow their units to work best with your vessel.

Assuming it’s not portable, its permanent placement should be decided based on the ambient temperatures you encounter based on your boating habits. Consider any extra support structures needed to install it correctly. Take note that I’m making these suggestions with the brand’s recommended install location for the specific unit in mind.

Ease of Install

Installation relates to cost and the effort you will have to exert to get the unit properly installed. What’s good is that these self-contained units often have the advantage of being plug and play, and you’ll only need to buy extra parts and assign a location for them. Most of the time a cabinet will do). Even so, most units will require wiring and plumbing, both of which will need a basic or mildly advanced understanding.

Noise

If the AC is in an area where you’ll be sleeping, you should pay attention to this often overlooked factor. I can vouch for the units featured in this review that address this issue.

Care and Maintenance

Most marine AC units are very low maintenance, to the point that they can take on years of “abuse” before they begin showing signs of wear and tear or a notable dip in performance. However, if you’re serious in extending the life of your unit, then it pays to perform tune-ups regularly. Before you do, though, make sure to consult the manual to know how you’ll go about maintaining or even if it’s advisable to do it yourself.

In most portable units, cleaning the vents and draining will do. As for standard self-contained units, most brands design the air filters to be removable, so it won’t be hard to clean. Make sure they’re free from dust build-ups to keep the airflow running and prevent possible freeze-ups. For this purpose, a vacuum and brush will be enough.

Check for the conditions of the connections, whether they’re corroded or not, as well as leaks in the system if your unit doesn’t come with a pressure gauge feature that reveals the system’s health. Examine the drain hose for clogging. You can use pressurized water from a hose to clear this up. Also, inspect the condenser coils for build-up of marine elements. It’s advised to have them flushed every two years if the AC is being used regularly.

Frequently Asked Questions

Who makes the most favorite marine air conditioner?

Webasto, to me, ticks the most checkboxes and offers high-quality, efficient, and marine-compliant units. Dometic is a very reputable brand with a huge support network. Most of their units have lengthy comprehensive warranties, which affirm their quality. The same is true for BLACK+DECKER.

Considering my varying but no less positive experiences with these brands, I recommend them all. More or less, they met my standards of durability, efficiency, install convenience, and price.

How do you size a marine air conditioner?

Multiply the length, width, and height of the boat to get a value in cubic feet. Afterward, multiply the total with 14 Btu if you’ll be placing the AC below deck or 17 Btu if it’s going topside.

You also need to be mindful of the climate zones you frequent, whether it’s mainly tropical, subtropical, temperate, or a mix of all three. Even factors such as average room temperature, humidity, insulation, window tinting, airflow, humidity, and currents should be considered if you want the optimal size.

How do you install a marine air conditioner?

It’s best to consult the exact instructions provided by the manufacturer to install your AC. Decide on the best location or compartment for your unit based on whether it will require extra wiring, ventilation, and plumbing.

Keep the thermostat away from any sources that might impact its reading, like direct sunlight. In the matter of plumbing for chilled water systems, you need to anticipate where you’ll be placing the pump that will be transferring water from a thru-hull to the unit. Preferably, the thru-hull should be the right height to keep the pump sucking water instead of air in the event that a vessel heels as is prevalent in most sailboats.

For most self-contained units, you can forgo the use of discharge ducts, but if it is required, be sure you use the right size for the area you intend to cool.

How do you flush a marine air conditioner?

If you’re using a chilled-water system, you’re likely to need to flush its lines to remove marine growth every 2 years. In most cases, a solution of ¼ parts muriatic acid and ¾ parts water will suffice. It’s best to buy a water hose adaptor to make it easy to connect the AC’s discharge hose with the water hose that you’ll be using for flushing.

Once connected, make sure the pump won’t suck seawater. Disengage the pump’s inlet then attach a separate hose for it through which you’ll be pouring the solution. But first, attach a funnel to its opposite end, then pour water into it to remove extra air that might have built up.

With that done, start the pump, which should flush the water inside the AC system. You can use this opportunity to add the solution to make sure you clean out the lines of more stubborn debris, like barnacles.

Conclusion

Now that you know the factors that define the best marine air conditioner, I hope you won’t have a difficult time deciding which unit to buy for your boat. When in doubt, always be mindful of the exact area of the space you want to cool, boat size, the power of each unit, and, of course, your budget. Doing so should set you in the right direction.

Jonathan Larson

I am passionate about water sports and technical fields, so combining both makes me interested in making contents about boat accessories. With my partner, we went on many trips and sports games together, which led us to think about how we can spread our joys and passions to many people.