*This unit works like a charm. Keeps my rv 21 x 41 very **Fastly.Cool** . I recommend to anyone that wants to keep a rv cold without having to turn on the main a/c.*
For me, the single most useful boat video on here. I aim to buy a boat in the next few years and for me AC and heating are a must. In fact I have decided I'm happier with a smaller monohull if I can kit it out with: water maker, hot water, heating, AC, a freezer and electric cooker. Murdock was the best!
Love your videos- great job detailing the switch to a 12V HVAC system. We just finished installing a 16K BTU Marinair in our 34’ Fountaine Pajot power cat. Very pleased compared to the old Mermaid air I had. Features of the Marinair unit are similar to the Mabru (except runs on 110V AC). It has variable speed fan and auto setting. Also has humidity sensor. Cools the whole boat pretty fast. Price was $1900. Hard to beat that. We dont have solar. So we use a Honda 2K generator when on the hook. Not quite as nice as solar/Li battery set up. We have 4 100 amp AGM batteries - not enough to push the Marinair. We do mostly coastal cruising around Florida so system set up works for us for now. Maybe someday we finally go for solar/Li.
Thank you for your very detailed video. Unfortunately, you have given me yet another project for my boat. When I first bought my boat, I had images of just sailing, entertaining friends, visiting exotic locations. Now I have fun things to do like add this air conditioner, upgrade my wiring to handle the new batteries I will need, etc.! Thanks for the video. Fair winds!
I'll never be able to afford one of the batteries shown near the start of this video, much less a boat to put it in, so why am I watching this video about replacing an expensive boat AC unit with an even more expensive AC (and 2 gauge copper runs, no less. Seriously, 2 gauge!) ? Well, aside from me being odd, it's because you two are always so cute together and seem so genuine and approachable. I guess it's the same reason people root for the underdog to prevail in sports, because where there are winners and losers you at least hope those that win are good people deserving of the win.
Question: In the Pacific I have gone snorkeling and drove down. Around 6 to 10 feet I noticed a dramatic drop in water temp, it was so pronounced there was a visible line between the warm surface water and the colder deep water. When anchored could you add a long hose to the water intake that extends down to the colder waters? That would save a LOT of power.
That’s called the thermocline. Interesting 🧐 dea…. Never thought of that, but you are so right. But….thermocline depth varies greatly…can be quite a ways down…. Interesting tho
Most people anchor in shallow water where the temperature happens to be stable. You need to be in quite deep water, in the summertime, to get down to the thermocline
Does the typical AC already pump saltwater to cool the radiator? Or does it make sense to have a flat radiator glued to the bilge to use the typically cooler water?
@@dejayrezme8617 yes, seawater is pumped thru the air con system for cooling. 2-Keel Coolers used to be popular and are still used on ships. They are basically flat, underwater radiators used to cool water before it goes into the AC
Wow! Huge difference, which in my mind, is a bargain for the additional cost. I love the tech shows and how well you present what can be a complicated topic. Really impressed with no bloodied knuckles or French! Thanks!
In 2010, my new semi tractor came with an A/C unit hard-wired into a 'house set' of 4 batteries, the old tech, wet-cell type. They would run that a/c 10 hours, enough for a truck driver's required rest, meaning that in places like California, with their 'no-idling' law, the truck engine didn't have to run to power the main a/c. That little unit in the sleeper worked great and so my biggest reason for not wanting to go on the California runs went away. Almost forgot: the company supplying those a/c units was 'D/C Cool'.
Also, your AC unit did not require marine water to be pumped up into the condenser intercooler which wastes more battery power. For less than 1/50th of the cost for the sail boat, we use wet cell batteries, a 24 VDC battery system and a single high efficiency inverter for our 5k btu AC unit that cost us $100. By the way our boat anchors in water so shallow that a water intercooler cannot be used.
A one-time cost of $3,200 for all-night cooling on batteries on a hot, sweaty summer? Sounds like a great investment, especially when you want to limit your diesel use!
Great find and the extra expense up front pays off on the longevity side. Even in a house furnace, an ac fan will cost $300 per year to run where as a dc fan will cost $30 annually, again more expensive up front but over 25 years way cheaper. Well done.
A ductless mini split is way better and way less money. They are so inexpensive you can afford to replace them every 2 years. A 21 sear 110volt uses 4 amps running and around 6 amps starting and under full load.
I got into air conditioning and refrigeration in 1961, and over the years I have a lot of questions about the subject. A water cooled heat pump does not have to be defrosted so it is the most effcient while heating. Look up the Tesla valve; it so simple with no moving parts to wear out, and he got the design in a dream from God. The pride, and joy of his work was the Tesla turbine. If a Tesla turbine/pump pumped water vapor it would be the most efficent a/c in the world. Big brother doesn't want us to know that water is the best refrigerant there is for a/c systems. The higher amout of latent heat of evaporation in b.t.u. the more efficient. Water at 970.4 btu per pound wins the race. The head pressure of a/c systems is about 200 pounds. Water is 14.7 psi. Which would draw the most amps? In a lithium bromide absorbtion system the temperture is 40 degrees F water is the refrigerant. Just marry the Tesla pump to it.
Phase change cooling is efficient but water doesn't have favorable characteristics for that in a practical machine. It's not a government conspiracy that water isn't used for air conditioning; it's physics.
@@LoanwordEggcorn Ice A/C works wonderfully. It used to be used on railroad cars. An example of how well it worked, take an 85'X10'X10' one in the Florida sun. Add 400 lbs of ice to start with. 90°F inside temp at the start and 15 minutes later it was at 75°. It kept it there for the next two hours. And it was good enough for US Presidents from 1942 to 1959. Local power company office building makes ice at night and uses it during the day. Saves them a batch of money.
@@gravelydon7072 How would that work in the middle of the ocean where there are no ice factories or power companies? P.S. The ice factories at that time used refrigeration like air conditioning to make the ice.
@@LoanwordEggcorn Ships use keel coolers. It can get really cold from them as they can dump large amounts of heat into the water. We used them for cooling out engines at a number of locations. Ice houses used a different type of cooling. Theirs was like the old Servel unit, Ammonia Cycle. You heat it up to cool thing down. And in colder locations, they went out and cut ice in the winter on the lakes and then stored it till needed.
I designed and built my own true DC air conditioner. I just finished the preliminary testing and I’m very excited to get this unit in our Bristol . The unit measured 10000 BTU at 21 amps at 12v at 60 degree water temp, it went up to 24 amps at 74 degree water temperature . I was hopping for 6000 BTU but it was higher then expected . It’s a totally different design as I didn’t like anything on the market and I want to run this unit off our batteries . It is truly 12v no inverter needed . It uses a variable speed compressor at full speed it did 14000btu while drawing only 36 amps at 12v . I tuned the system to be more efficient at low speed but if I tuned it for max speed I’m sure I could squeeze more BTUs of of it at less power.
@@TheOKellys Thank you , yes that includes a dc feed water condensing pump , I used a small mag drive unit that only takes an amp at 12v . Over sized the condenser so the unit doesn’t need as much flow . Also I’m using a TXV and a few other tricks in the design to keep compressor temperatures down . I did make a little video of my first design but I totally changed that on the final build to get the results that I did .O yes and the Masterflux compressor is multi speed . But I tune the system to be most efficient at a certain refrigerant flow rate with the TXV . "the sweet spot" I don't change the fan speed I just close the vent to slow the air flow which drops the amps that the fan takes . The fan is also over sized. The unit is completely enclosed so you do not see any of the components , this has the advantage of making the unit whisper quite you cant hear it run other then the air coming out of the vents. Sorry for the ramble.
Thanks for this video, i m designing off grid power systems for my house and RV. Firstly i am an aircraft electrician so I carefully calculate before building. 12 VOLT DC maybe better than 110 VOLT AC, BUT.... 24 VOLT DC is even better, its half the amps and therefore half the size of power cable required. My batteries I built myself from 6 old Toyota Prius/CamryHybrid NiMh batteries, This is around 200 CELLS in 12 CELL BLOCKS at 25 VOLTS, eg 600 WATT HOUR per 12 CELLS. Thats 16 BLOCKS that weight 10 KGS each for a total of 10 KWH and 150 KGS. Caveat is charging NiMh batteries required a custom designed microprocessor charging system that I also had to design myself as NiMH cells require delta temp/temp charging cutoff. eg temp rise of 2 degress per min. Here in Australia I have trouble sourcing hybrid batteries and cells, but in the USA there is an abundance of secondhand cellsl (i forgot to mention I conditiion all my cells first to have usually 110% to 120% min capacity, not expensive as i use radio control model type chargers). Most people dont understand that other than weight lithium batteries are NOT the best choice. Put it this way, ALL satellites in space use NiMh type cells and batteries, with minimum life expectancy of 25 years. NiMh can discharge to ZERO volts and recover and DONT blow up or catch fire. I paid about $300 USD total for my 6 hybrid batteries, that give me 10 KWH. Just thought this might be a cost effective marine solution for any technical boat owners out there. Let me know if you want more information OZ
When it’s 90 degrees with 90 percent humidity at night and you are trying to sleep with fans in a small enclosed space 5300 dollars is NOTHING ! Being hot during the day while you are working or lounging about is one thing but a good nights sleep in a comfortable environment is priceless. ❤
Thanks for posting this video. As I start in a refit of a 35-year-old trawler, I am looking for the latest technology for a 1400 Ah LiFePO4 battery bank. This is awesome as my wife and I always love our cool sleeping cabin but are looking to live off-grid as much as possible.
At 1:26 your old unit was so completely blocked with dirt & lint that it had no chance of working. If you do that to your new unit you'll get the same bad result. Use a vacuum and clean it every year or two.
Great video. I did notice in the video you appeared to be recording the BTUs from very different locations. The old unit you seemed to be measuring 4 to 6 inches away from an exhaust. For the new unit it was being measured inside a sealed duct directly at the AC unit. But in the end if the power draw is lower and its sufficiently cooling your space, that's all that really matters.
Sounds fantastic for off grid homesteading in Brandon Fl., combined with aircrete insulation and appropriate volume, P × V = n R ×T . Thank you for posting.
Actually, the modern day DC to DC converter or DC to AC inverter are both very power efficient from 95~98%. There are very little power loss during voltage conversion. The main reason that the new Mabru unit is much power efficient than your old unit is because it use variable frequency drive motor, so instead on/off, it basically just slow down. If you can fit the household AC (VFD type) on your boat, it will be quite efficient as well :)
@@TheOKellys Let me know when you get the second Mabru in the other hull and maybe we"ll come 'round for an overnight test--My sleeping 57 year old spouse is the perfect HVAC tester. ;-)
Ive played with silly stuff. I had an incident with Lithium and immediately went to AGM. Everyone has a preference and reason but in MY case the batteries became hot, very fast! SV, Solar panels, Wind Gen, Hydrogenerators x2. The $400 Inverter crapped out and we started to cook. When the Halon tanks dump and the alarm sounds get ready to swim. Granted, this is not common BUT here is why i went AGM. 1 Less replacement cost 2 Can be found world wide 3 Charge slower but maintain capacity and rarely get hot enough to drop Halon
Looking at those numbers, the aircon is running way more efficiently at full speed, so you would be much better to run a full speed and cycle the unit on/off as necessary.
Yep, good point. I wonder why they even have the "mid-speed" since it's not efficient at all in comparison? Somehow I guess it keeps a more stable room temp (luxury mode)? hmmmm?
@@TheOKellys Here's my educated guess - at full speed you'll get about 7,500 BTUH and at part load you'll get about 4,150 BTUH. Maybe a little more at part load because it will be all sensible heat whereas in cooling mode you were probably dehumidifying at part load. As you might have guessed by now, I design HVAC systems. ;-)
These are made and designed by a Chinese company called Hopewell. You can order one direct for about $1200. Used to be able to get them for less than $700 but the popularity caught up with them. The mabru markup is obscene and they are dishonest about their exclusivity, origin and "patent pending". I use a Chinese 12v mini split on my boat, slightly less efficient (older compressor, though I have seen units using the same boyard compressor recently) and it cost me $600 delivered.
Imitation is the best flattery. There is nothing dishonest about the way that we do business but there are plenty of misinformed people out there thinking that they can purchase a real Rolex in Chinatown.
Good stuff nothin' like yanking out old outdated tech! Many RV's are moving to 12 volt fridge compressors to save on power and work well on batteries that are solar charged. That way you can get rid of propane.
Nick, great video sir. A few questions: 1. Do they offer a 24VDC or 48VDC and would that have better efficiencies as you go up in voltage? 2. Also, most boat A/C units are in the 9,000 - 16,000 BTU units. Do they offer larger BTU units (9,000-16,000) and are they as efficient ?
My uneducated guess (trying to learn electric motor) is that 12v or 48v shouldn't make a difference in efficiency if both motors are sized correctly. If both motors have 80% efficiency you need to put the same amount of electrical energy in to compress a certain amount of refrigerant. I also think they should be able to run a 12V motor on 48V using a simple PWM motor controller. Not sure about that though.
@@dominiclorenti7758 You might have to wait awhile as 12 volt is more common, that is why you are starting to see 12 volt compressor type refrigerators in RV's.
You are much different than me. AC is definitely a priority especially when sleeping. On my list of priorities a hole in the boat is the only thing on the priority list that beats fixing the AC and just barely.
I am not a A/C tech. But I do believe that it is not a evaporator. It is called a condenser The condenser is responsible for taking the pressurized gas from the compressor and changing it into a liquid vapor. The evaporator coil is the part of the air conditioning system that sits inside of your home near the air handler and is where the refrigerant absorbs heat. Thereby cooling the air. being in marine industry I have seen Cruisair units for decades and i must say, the all copper larger one is far superior. I like the Mabru unit more, however all that copper does come at a hefty price difference. I am very interested in the ability to A/C any space on DC power instead of AC. for a camper, work truck a marine vessel its the way to go whatever voltage system is being used 12v, 24v etc. I enjoyed your presentation and the channel thank you for the information.
Really enjoy your vids. Tons of info. Thanks. My wife and I have always dreamed of life on a sailboat. Before we jump all in we would love to spend some time with someone on the water for a week at least to get a hands on experience. Do you know of anyone you could recommend that charters in the carribean.
You referred to putting in BTU’s. That is the measurement of heat and is equal to about a match. The definition of refrigeration is the removal of those btus which is taken out by condensing which I would say is likely a water loop under your boat. Water is the best way for the transfer
Great Video on the 7k btu Mabru Unit! Just wondering how the unit performs in warmer testing conditions (like 28 degrees Celsius water and 35 air temperature) in terms of btu output and power consumption? Do the 28ah include the water pump?
pretty sure the cooling was the goal.. but the heating will come in realy handy some cold days and will help stay longer on the boat in the off season or between
Just bought a 12000 BTU 115v unit two days ago , the customer service so far was outstanding 😀 I’ll let you how the install goes doing it myself SV PLOT TWIST. USVI
Hello are you only using this unit to cool your bedroom? Can it also cool the saloon or would that not be needed as I remember you saying in your video? Thank you.
One question, do you still need a "soft Switch" due to the initial pull of amps on the battery in the initial startup phase of the AC? Once again GREAT video guys!
Nice video. Very detailed. I would have liked to have seen (or heard) how the heater worked that night. How was it? The price isn't bad, once you consider the heating too. Thanks again!!
Taking the generator off the boat is a big call. We are in New Zealand at the moment cruising on our Leopard 48 and there is not enough solar power (sun) in this country to be without the generator compared to sunny tropical areas. One has to consider future cruising locations for the vessel when making such decisions. Even with good lithium, if one takes the power out you have to still get the power back in to the batteries. Keep up the good work with the videos thanks. I learn lots.
Nice, clean install, right wire sizing, etc. Why didn't they just say it's a 'heat pump' if it also runs in the 'reverse' cycle also ... I'm not so sure their installation accommodates it, ducting-wise.
Just FYI, The man responsible for that highly efficient little air conditioner (Alain Mabru) pronounces his last name with a long "a" not a short one. It would be spoken like you would say "Maybrew." He's a very talented fellow that I met quite a few years back in the mid 80's while we were both working out of Merrill - Stevens Yacht Yard in Dania, Florida.
I, of course like that it is 12 volt and very efficient but I still think I want to go with a mini split type system for my trawler. I want to be able to run the a/c all night without having to think about the sea water pump running continuously and the possibility of it filling the bilge with water while I'm asleep. And there are a few 12 volt mini splits available now. The only 2 draw backs are the looks and mounting of the outside unit and draining the condensate out of a thru hull. Both should be easly overcome with a little planning. .
Hello my dear friends, how are you both doing? Such a great video. I learned so much about ACs in a boat. It is so important for so many people. Thank you for the information. Wishing you a great trip out of Annapolis. Cheers from Canary Islands.
I saw that, but in today's world in which many cruisers have 24V or 48V systems it just makes sense to offer more. FWIW, many of the RV DC-powered Air Conditioning units are available in 12/24/48.
@@TonyBurnett1492 Agree, but perhaps they started from larger and smaller boats where AC or 12V was more appropriate. RVs are a fairly different market.
Is the evaporator protected against corrosion? Copper has a good thermal conductivity, but the thermal conductivity of copper oxide is lower than 1/10th of that of copper. This would mean that you would loose a lot of performance over time when the copper corrodes. When aluminum corrodes it forms aluminum oxide, which protects the aluminum from corroding any further, i.e. aluminum is more stable.
Thank you for the a.c. update. Glad to see 👀 this stuff working. So head south as fast as you can so you can use it. And give a report on how it is working. 👍 ok. Until next week Aloha from the Big Island 🏝 of Hawaii 🏝. P.S. where it is summer all the time ⏲
The comparison was great how did you get all the data with what type of equipment and app or software. Already told a friend with a cat like yours. I help businesses reduce their HVAC on Roof Top Units (RTU HVAC systems) so this would be very helpful software or equipment. Thanks for the great video and education. Mark
*This unit works like a charm. Keeps my rv 21 x 41 very **Fastly.Cool** . I recommend to anyone that wants to keep a rv cold without having to turn on the main a/c.*
Always beneficial when you’re paying for quality. Copper is an unavoidable but retrievable cost. Sleeping comfortably is priceless
For me, the single most useful boat video on here. I aim to buy a boat in the next few years and for me AC and heating are a must. In fact I have decided I'm happier with a smaller monohull if I can kit it out with: water maker, hot water, heating, AC, a freezer and electric cooker. Murdock was the best!
Love your videos- great job detailing the switch to a 12V HVAC system. We just finished installing a 16K BTU Marinair in our 34’ Fountaine Pajot power cat. Very pleased compared to the old Mermaid air I had. Features of the Marinair unit are similar to the Mabru (except runs on 110V AC). It has variable speed fan and auto setting. Also has humidity sensor. Cools the whole boat pretty fast. Price was $1900. Hard to beat that. We dont have solar. So we use a Honda 2K generator when on the hook. Not quite as nice as solar/Li battery set up. We have 4 100 amp AGM batteries - not enough to push the Marinair. We do mostly coastal cruising around Florida so system set up works for us for now. Maybe someday we finally go for solar/Li.
Thank you for your very detailed video. Unfortunately, you have given me yet another project for my boat. When I first bought my boat, I had images of just sailing, entertaining friends, visiting exotic locations. Now I have fun things to do like add this air conditioner, upgrade my wiring to handle the new batteries I will need, etc.! Thanks for the video. Fair winds!
I'll never be able to afford one of the batteries shown near the start of this video, much less a boat to put it in, so why am I watching this video about replacing an expensive boat AC unit with an even more expensive AC (and 2 gauge copper runs, no less. Seriously, 2 gauge!) ? Well, aside from me being odd, it's because you two are always so cute together and seem so genuine and approachable. I guess it's the same reason people root for the underdog to prevail in sports, because where there are winners and losers you at least hope those that win are good people deserving of the win.
This video is right on time. I'm about to buy a 56 Formosa and I will have to replace the old a/c unit. Talk about perfect timing. Thanks guys.
Love the: 'Mike Patey" move - HA!
Only aviation geeks will get it!!!
Let’s get back to work! Lol
@@TheOKellys
Ha, ha, ha!!!!!
Don't go ground looping Clarity :-)
The catamaran world needs a Mike Patey
@@donjohnston3776
You got that right, just image the innovation that would come from him and his brother!!!
Question: In the Pacific I have gone snorkeling and drove down. Around 6 to 10 feet I noticed a dramatic drop in water temp, it was so pronounced there was a visible line between the warm surface water and the colder deep water. When anchored could you add a long hose to the water intake that extends down to the colder waters? That would save a LOT of power.
That’s called the thermocline. Interesting 🧐 dea…. Never thought of that, but you are so right. But….thermocline depth varies greatly…can be quite a ways down…. Interesting tho
Most people anchor in shallow water where the temperature happens to be stable. You need to be in quite deep water, in the summertime, to get down to the thermocline
In the inland houseboat market, those are called Marine AC. They will freeze you out.
Does the typical AC already pump saltwater to cool the radiator?
Or does it make sense to have a flat radiator glued to the bilge to use the typically cooler water?
@@dejayrezme8617 yes, seawater is pumped thru the air con system for cooling.
2-Keel Coolers used to be popular and are still used on ships. They are basically flat, underwater radiators used to cool water before it goes into the AC
Mr. T was the MacGyver of the A Team
Lol
I frigging love watching you guys!!!
Wow! Huge difference, which in my mind, is a bargain for the additional cost. I love the tech shows and how well you present what can be a complicated topic. Really impressed with no bloodied knuckles or French! Thanks!
In 2010, my new semi tractor came with an A/C unit hard-wired into a 'house set' of 4 batteries, the old tech, wet-cell type. They would run that a/c 10 hours, enough for a truck driver's required rest, meaning that in places like California, with their 'no-idling' law, the truck engine didn't have to run to power the main a/c. That little unit in the sleeper worked great and so my biggest reason for not wanting to go on the California runs went away. Almost forgot: the company supplying those a/c units was 'D/C Cool'.
Also, your AC unit did not require marine water to be pumped up into the condenser intercooler which wastes more battery power. For less than 1/50th of the cost for the sail boat, we use wet cell batteries, a 24 VDC battery system and a single high efficiency inverter for our 5k btu AC unit that cost us $100. By the way our boat anchors in water so shallow that a water intercooler cannot be used.
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Q?: What brand of house batteries were those? Also, were they deep cycle?
A one-time cost of $3,200 for all-night cooling on batteries on a hot, sweaty summer? Sounds like a great investment, especially when you want to limit your diesel use!
It costs more to talk about it than the money spent for sure. It doesn't pay to be cheap.
$3200? he said it was $5300
Worth every Penny
Great find and the extra expense up front pays off on the longevity side. Even in a house furnace, an ac fan will cost $300 per year to run where as a dc fan will cost $30 annually, again more expensive up front but over 25 years way cheaper. Well done.
Had no idea!
A ductless mini split is way better and way less money. They are so inexpensive you can afford to replace them every 2 years. A 21 sear 110volt uses 4 amps running and around 6 amps starting and under full load.
@@TheOKellys I may be wrong on this but I suspect the difference is due to not having a transformer involved transformers are big time energy hogs.
I got into air conditioning and refrigeration in 1961, and over the years I have a lot of questions about the subject. A water cooled heat pump does not have to be defrosted so it is the most effcient while heating. Look up the Tesla valve; it so simple with no moving parts to wear out, and he got the design in a dream from God. The pride, and joy of his work was the Tesla turbine. If a Tesla turbine/pump pumped water vapor it would be the most efficent a/c in the world. Big brother doesn't want us to know that water is the best refrigerant there is for a/c systems. The higher amout of latent heat of evaporation in b.t.u. the more efficient. Water at 970.4 btu per pound wins the race. The head pressure of a/c systems is about 200 pounds. Water is 14.7 psi. Which would draw the most amps? In a lithium bromide absorbtion system the temperture is 40 degrees F water is the refrigerant. Just marry the Tesla pump to it.
Is there a problem with water freezing and expanding though?
Phase change cooling is efficient but water doesn't have favorable characteristics for that in a practical machine. It's not a government conspiracy that water isn't used for air conditioning; it's physics.
@@LoanwordEggcorn Ice A/C works wonderfully. It used to be used on railroad cars. An example of how well it worked, take an 85'X10'X10' one in the Florida sun. Add 400 lbs of ice to start with. 90°F inside temp at the start and 15 minutes later it was at 75°. It kept it there for the next two hours. And it was good enough for US Presidents from 1942 to 1959. Local power company office building makes ice at night and uses it during the day. Saves them a batch of money.
@@gravelydon7072 How would that work in the middle of the ocean where there are no ice factories or power companies?
P.S. The ice factories at that time used refrigeration like air conditioning to make the ice.
@@LoanwordEggcorn Ships use keel coolers. It can get really cold from them as they can dump large amounts of heat into the water. We used them for cooling out engines at a number of locations.
Ice houses used a different type of cooling. Theirs was like the old Servel unit, Ammonia Cycle. You heat it up to cool thing down. And in colder locations, they went out and cut ice in the winter on the lakes and then stored it till needed.
I designed and built my own true DC air conditioner. I just finished the preliminary testing and I’m very excited to get this unit in our Bristol .
The unit measured 10000 BTU at 21 amps at 12v at 60 degree water temp, it went up to 24 amps at 74 degree water temperature . I was hopping for 6000 BTU but it was higher then expected . It’s a totally different design as I didn’t like anything on the market and I want to run this unit off our batteries . It is truly 12v no inverter needed . It uses a variable speed compressor at full speed it did 14000btu while drawing only 36 amps at 12v . I tuned the system to be more efficient at low speed but if I tuned it for max speed I’m sure I could squeeze more BTUs of of it at less power.
WOW! Sounds really cool. (Get it?). Question...are you running a DC feed pump and is that variable speed as well?
@@TheOKellys Thank you , yes that includes a dc feed water condensing pump , I used a small mag drive unit that only takes an amp at 12v . Over sized the condenser so the unit doesn’t need as much flow . Also I’m using a TXV and a few other tricks in the design to keep compressor temperatures down . I did make a little video of my first design but I totally changed that on the final build to get the results that I did .O yes and the Masterflux compressor is multi speed . But I tune the system to be most efficient at a certain refrigerant flow rate with the TXV . "the sweet spot" I don't change the fan speed I just close the vent to slow the air flow which drops the amps that the fan takes . The fan is also over sized. The unit is completely enclosed so you do not see any of the components , this has the advantage of making the unit whisper quite you cant hear it run other then the air coming out of the vents. Sorry for the ramble.
Right on. I can even follow what you are saying. Big demand out there for something like this!
Excellent, cudos to Mabru for an excellent product!
When you sell that behemoth of a generator it will offset the cost of the upgrade even more. Totally worthwhile upgrade. Well done.
Thanks for this video, i m designing off grid power systems for my house and RV. Firstly i am an aircraft electrician so I carefully calculate before building.
12 VOLT DC maybe better than 110 VOLT AC, BUT.... 24 VOLT DC is even better, its half the amps and therefore half the size of power cable required. My batteries I built myself from 6 old Toyota Prius/CamryHybrid NiMh batteries, This is around 200 CELLS in 12 CELL BLOCKS at 25 VOLTS, eg 600 WATT HOUR per 12 CELLS. Thats 16 BLOCKS that weight 10 KGS each for a total of 10 KWH and 150 KGS. Caveat is charging NiMh batteries required a custom designed microprocessor charging system that I also had to design myself as NiMH cells require delta temp/temp charging cutoff. eg temp rise of 2 degress per min. Here in Australia I have trouble sourcing hybrid batteries and cells, but in the USA there is an abundance of secondhand cellsl (i forgot to mention I conditiion all my cells first to have usually 110% to 120% min capacity, not expensive as i use radio control model type chargers). Most people dont understand that other than weight lithium batteries are NOT the best choice. Put it this way, ALL satellites in space use NiMh type cells and batteries, with minimum life expectancy of 25 years. NiMh can discharge to ZERO volts and recover and DONT blow up or catch fire.
I paid about $300 USD total for my 6 hybrid batteries, that give me 10 KWH. Just thought this might be a cost effective marine solution for any technical boat owners out there. Let me know if you want more information OZ
"Mike Patey" back to work!! love it.
Back to work! That guy!
@@TheOKellys proof you are a genuine aviation enthusiast!
Awesome... I've always wondered if there was a bit more that could be done on the AC front.
When it’s 90 degrees with 90 percent humidity at night and you are trying to sleep with fans in a small enclosed space 5300 dollars is NOTHING ! Being hot during the day while you are working or lounging about is one thing but a good nights sleep in a comfortable environment is priceless. ❤
Thanks for posting this video. As I start in a refit of a 35-year-old trawler, I am looking for the latest technology for a 1400 Ah LiFePO4 battery bank. This is awesome as my wife and I always love our cool sleeping cabin but are looking to live off-grid as much as possible.
enjoy your warm night
At 1:26 your old unit was so completely blocked with dirt & lint that it had no chance of working. If you do that to your new unit you'll get the same bad result. Use a vacuum and clean it every year or two.
It was tested without the screen and with the screen. No difference.
Great video. I did notice in the video you appeared to be recording the BTUs from very different locations. The old unit you seemed to be measuring 4 to 6 inches away from an exhaust. For the new unit it was being measured inside a sealed duct directly at the AC unit. But in the end if the power draw is lower and its sufficiently cooling your space, that's all that really matters.
Yeh plenty of errors, that’s why I said even if putting out full btu, it’s still half the efficiency in the dometic. But good eye!
The probes were different . Anemometer in old AC shot the one in the duct of the mabru was a temperature probe measuring outlet temp.
Great upgrade. That thing looks like it’s 10 times the machine of the old one. Quality is worth the money not to mention the efficiency
Agree with you there!
Sounds fantastic for off grid homesteading in Brandon Fl., combined with aircrete insulation and appropriate volume, P × V = n R ×T . Thank you for posting.
lets go brandon
Actually, the modern day DC to DC converter or DC to AC inverter are both very power efficient from 95~98%. There are very little power loss during voltage conversion. The main reason that the new Mabru unit is much power efficient than your old unit is because it use variable frequency drive motor, so instead on/off, it basically just slow down. If you can fit the household AC (VFD type) on your boat, it will be quite efficient as well :)
Where is the condenser unit for that A/C? Is it some kind of salt water heat exchanger located near the engine room?
@Gulf Nautical Thanks Gulf Nautical for the explanation, that makes it a very compact unit compared to say a Mini-split.
I love Mike Patey
Ooooh yeah: Love it when I have to pause your video because you just mention something new. Like a 12 Volt Air conditioner.
Did you install one on the other hull? Just wondering…. Always wondered if folks also put AC for the Salon….
Not yet. We have two other aircons. Let’s see how this Mabru does for a bit before we commit. So far…
@@TheOKellys Let me know when you get the second Mabru in the other hull and maybe we"ll come 'round for an overnight test--My sleeping 57 year old spouse is the perfect HVAC tester. ;-)
Mike Patey, Back to work reference, probably only fellow aviators would get this. Love it.
Glad you noticed. Now, back to work. Lol
Thanks for the great tip on the A/C unit. I'll certainly be looking them up when I'm refitting my boat.
Ive played with silly stuff.
I had an incident with Lithium and immediately went to AGM. Everyone has a preference and reason but in MY case the batteries became hot, very fast! SV, Solar panels, Wind Gen, Hydrogenerators x2. The $400 Inverter crapped out and we started to cook. When the Halon tanks dump and the alarm sounds get ready to swim.
Granted, this is not common BUT here is why i went AGM.
1 Less replacement cost
2 Can be found world wide
3 Charge slower but maintain capacity and rarely get hot enough to drop Halon
Looking at those numbers, the aircon is running way more efficiently at full speed, so you would be much better to run a full speed and cycle the unit on/off as necessary.
Yep, good point. I wonder why they even have the "mid-speed" since it's not efficient at all in comparison? Somehow I guess it keeps a more stable room temp (luxury mode)? hmmmm?
I used 12 volt fans and a damp towel on my live on sailboat during hot summer nights. The fresh water deck shower was very helpful.
I got the Mike Patey reference. Forgot that Nick is a pilot. Flying cowboys are a great crew.
Great thumbnail, Nick and Megan! Received MORE OF YOUR COFFEE!!!!!! Life is good! Cheers,
Thank you! We got a new shipment on board today too whoop whoop! Thanks for ordering more coffee, it’s so good!
Enjoy the cruise to Hatteras, I'll be in Emerald isle NC Nov 6th for a week. A little further south yet.
We adore Emerald Isle!…..Enjoy yourself, we are definitely jealous.
@@larrimos I sure will. Been fishing the Bogue Inlet pier in the fall since the early 60's.
Can you give us the btu and amp hr for the heat ? Inquiring minds want to know 🤔
Good idea. Will supply that coming up
@@TheOKellys Here's my educated guess - at full speed you'll get about 7,500 BTUH and at part load you'll get about 4,150 BTUH. Maybe a little more at part load because it will be all sensible heat whereas in cooling mode you were probably dehumidifying at part load. As you might have guessed by now, I design HVAC systems. ;-)
Thanks for the video sir!
These are made and designed by a Chinese company called Hopewell. You can order one direct for about $1200. Used to be able to get them for less than $700 but the popularity caught up with them. The mabru markup is obscene and they are dishonest about their exclusivity, origin and "patent pending". I use a Chinese 12v mini split on my boat, slightly less efficient (older compressor, though I have seen units using the same boyard compressor recently) and it cost me $600 delivered.
Supply source for your info please
Imitation is the best flattery. There is nothing dishonest about the way that we do business but there are plenty of misinformed people out there thinking that they can purchase a real Rolex in Chinatown.
@@nicolasmabru so are you saying that you don't purchase your units from Hopewell? Where are they made?
Good stuff nothin' like yanking out old outdated tech! Many RV's are moving to 12 volt fridge compressors to save on power and work well on batteries that are solar charged. That way you can get rid of propane.
Love the thumb nail, kudos to the photographer!
Why thankya! The model did all the heavy lifting!
The Mike Patey move. I'm impressed I was just catching up on Scrappy progress. I wonder how many sailors are also pilots?
Nick, great video sir. A few questions:
1. Do they offer a 24VDC or 48VDC and would that have better efficiencies as you go up in voltage?
2. Also, most boat A/C units are in the 9,000 - 16,000 BTU units. Do they offer larger BTU units (9,000-16,000) and are they as efficient ?
I believe they have a 12000 btu….you’ll have to talk to them about the other voltages….not sure. My guess would be yes…
Andre from Gulf Nautical can definitely get you a high output DC air conditioner.
I’m waiting for the 48vdc unit
My uneducated guess (trying to learn electric motor) is that 12v or 48v shouldn't make a difference in efficiency if both motors are sized correctly. If both motors have 80% efficiency you need to put the same amount of electrical energy in to compress a certain amount of refrigerant.
I also think they should be able to run a 12V motor on 48V using a simple PWM motor controller. Not sure about that though.
@@dominiclorenti7758 You might have to wait awhile as 12 volt is more common, that is why you are starting to see 12 volt compressor type refrigerators in RV's.
Wow, what a difference!
You are much different than me. AC is definitely a priority especially when sleeping. On my list of priorities a hole in the boat is the only thing on the priority list that beats fixing the AC and just barely.
Getting boaring😉 with all these excellent shows, you set the bar at a new level each week, and always look for my o’kelley fix each week! Great find!
Awww, thanks Mark
Very impressive indeed. You will enjoy the cool without bugs and with NO ENERGY GUILT! Enjoy!
Thanks John, so true about the guilt and the morning check in on the damage 🤣
@@TheOKellys sad to disappoint thousands of no-see-ups, eh?
Mike Patey motion! Awesome!
Another DIYer!!
I run into the same dilemma in the trucking industry. Thanks for the video.
I am not a A/C tech. But I do believe that it is not a evaporator. It is called a condenser
The condenser is responsible for taking the pressurized gas from the compressor and changing it into a liquid vapor. The evaporator coil is the part of the air conditioning system that sits inside of your home near the air handler and is where the refrigerant absorbs heat.
Thereby cooling the air. being in marine industry I have seen Cruisair units for decades and i must say, the all copper larger one is far superior. I like the Mabru unit more, however all that copper does come at a hefty price difference. I am very interested in the ability to A/C any space on DC power instead of AC. for a camper, work truck a marine vessel its the way to go whatever voltage system is being used 12v, 24v etc. I enjoyed your presentation and the channel thank you for the information.
In a self contained marine unit the condenser and evaporator sit next to each other unlike the split system on a home.
Really enjoy your vids. Tons of info. Thanks. My wife and I have always dreamed of life on a sailboat. Before we jump all in we would love to spend some time with someone on the water for a week at least to get a hands on experience. Do you know of anyone you could recommend that charters in the carribean.
You referred to putting in BTU’s. That is the measurement of heat and is equal to about a match. The definition of refrigeration is the removal of those btus which is taken out by condensing which I would say is likely a water loop under your boat. Water is the best way for the transfer
Great Video on the 7k btu Mabru Unit! Just wondering how the unit performs in warmer testing conditions (like 28 degrees Celsius water and 35 air temperature) in terms of btu output and power consumption? Do the 28ah include the water pump?
I enjoy your humor.
now you done it. cooling and heating. That is awesome.
pretty sure the cooling was the goal.. but the heating will come in realy handy some cold days and will help stay longer on the boat in the off season or between
Great video, love the Mike Patey reference!
Just bought a 12000 BTU 115v unit two days ago , the customer service so far was outstanding 😀 I’ll let you how the install goes doing it myself SV PLOT TWIST. USVI
Sweet. Let us know!
Hello are you only using this unit to cool your bedroom?
Can it also cool the saloon or would that not be needed as I remember you saying in your video?
Thank you.
Nice. As we get a little older we do like comfort
Thanks. Very helpful video.
The well pump that you referenced is for what? Is this a water cooled unit or is the pump for something else?
Are 12V A/C's like this going to be coming in towable campers. We are looking for a Grand Design Imagine 22MLE.
Awesome analysis, thanks! Could this unit be installed in a campervan? Is there a shroud for the condenser to push the heat outside?
Great video - really unbelievable amount of efficiency and the best part, it will actually be cool / warm the entire time you need it!
It’s amazing.
A heater too! Someone is getting lucky tonight!!
Great work Andre!
Da man!
Thanks Phil!! Your work inspires us. Look forward to collaborating with you in the future.
One question, do you still need a "soft Switch" due to the initial pull of amps on the battery in the initial startup phase of the AC? Once again GREAT video guys!
Nope! How bout that!
@@TheOKellys Yep, the new AC is DC :)
Call it Lola....
Amazing. I want one. Can’t afford one or justify one, but I WANT IT!!
...wasn´t expecting it to "come with an installer"...THAT WAS SO FUNNY!!!!!...thank you for your videos...always very instructive.
Cool. I dropped a Velair 16k btu into my Monohull - which Gulf Nautical also sells. It's a great option.
+1 for the Mike Patey reference.... Back to Work!!!
I noticed you ran the condensation drain into the bilge instead of a filtered fresh water tank.
Good. Who wants to drink dead skin water 🤮
Nice video. Very detailed. I would have liked to have seen (or heard) how the heater worked that night. How was it? The price isn't bad, once you consider the heating too. Thanks again!!
One of our dealers did a video of the heating function of out 7DC th-cam.com/video/juUhLee-g_I/w-d-xo.html
Taking the generator off the boat is a big call. We are in New Zealand at the moment cruising on our Leopard 48 and there is not enough solar power (sun) in this country to be without the generator compared to sunny tropical areas. One has to consider future cruising locations for the vessel when making such decisions. Even with good lithium, if one takes the power out you have to still get the power back in to the batteries. Keep up the good work with the videos thanks. I learn lots.
Yessir, still need it in the high latitudes.
jemust r7n dusel genertor 5 oerc zrto emsin disel gad
Nice, clean install, right wire sizing, etc. Why didn't they just say it's a 'heat pump' if it also runs in the 'reverse' cycle also ... I'm not so sure their installation accommodates it, ducting-wise.
These ac systems is it evaporative or refrigerated cooling ?
I'm not a boat owner and I'm on the grid. What is available for my bedroom? It has to be super quiet.
portabke ac 1400 wayß
@@sharonbraselton4302 link?
You should have shown the unboxing of the Installer.
Did his box have any air holes? Was the installer wearing a diaper during shipping?
Hahahahahahhaa….he did it like in Thomas Crown Affair. Scuba!
Just FYI, The man responsible for that highly efficient little air conditioner (Alain Mabru) pronounces his last name with a long "a" not a short one. It would be spoken like you would say "Maybrew." He's a very talented fellow that I met quite a few years back in the mid 80's while we were both working out of Merrill - Stevens Yacht Yard in Dania, Florida.
Oh darn! had no idea. sorry Alain!
Yes because it’s French 😁. He is a brilliant man.
I, of course like that it is 12 volt and very efficient but I still think I want to go with a mini split type system for my trawler. I want to be able to run the a/c all night without having to think about the sea water pump running continuously and the possibility of it filling the bilge with water while I'm asleep. And there are a few 12 volt mini splits available now.
The only 2 draw backs are the looks and mounting of the outside unit and draining the condensate out of a thru hull. Both should be easly overcome with a little planning.
.
Great ac unit....the fact that it is also reverse cycle as well is awesome..!
Thank you! We need it right now it’s chilly in Virginia!
LETS GET BACK TO WORK!!! LOVE the nod to Mike Patey!! He is rocking the aircraft world! I do planes too! Sail boats, planes and motorcycles!
I got close to buying a Wilga in 2007, so when I came across Mike….the MAN!
Thank You!
Hello my dear friends, how are you both doing?
Such a great video. I learned so much about ACs in a boat. It is so important for so many people.
Thank you for the information. Wishing you a great trip out of Annapolis. Cheers from Canary Islands.
Hello Carlos, so great to hear from you! We are doing great and hope you are too!
Seems like they should make a 24V or 48V version in order to reduce amp draw and thus cable diameter ($$).
Looks like they only have 12V or high voltage AC.
I saw that, but in today's world in which many cruisers have 24V or 48V systems it just makes sense to offer more. FWIW, many of the RV DC-powered Air Conditioning units are available in 12/24/48.
@@TonyBurnett1492 Agree, but perhaps they started from larger and smaller boats where AC or 12V was more appropriate. RVs are a fairly different market.
Is the evaporator protected against corrosion? Copper has a good thermal conductivity, but the thermal conductivity of copper oxide is lower than 1/10th of that of copper. This would mean that you would loose a lot of performance over time when the copper corrodes. When aluminum corrodes it forms aluminum oxide, which protects the aluminum from corroding any further, i.e. aluminum is more stable.
Love the respect for Mike Patey at 6:26. Not sure I like that fact that HM Murdock isn't well loved though, Nick! :(
Cheers guys
Best investment! A good nights sleep = happy crew = happy sailing!!!!! A/C is worth every penny!
Like the Mike Patey back to work!
Thanks for the comment. Now, back to work! Lol
great editing explaining something not so easyly presented.
Loved it.
Thank you for the a.c. update. Glad to see 👀 this stuff working.
So head south as fast as you can so you can use it. And give a report on how it is working.
👍 ok. Until next week Aloha from the Big Island 🏝 of Hawaii 🏝.
P.S. where it is summer all the time ⏲
Oh man! We are ready!
The comparison was great how did you get all the data with what type of equipment and app or software. Already told a friend with a cat like yours. I help businesses reduce their HVAC on Roof Top Units (RTU HVAC systems) so this would be very helpful software or equipment. Thanks for the great video and education. Mark
I like to run a condensate pump through a filter and add to fresh water supply
Does the Maubru need a soft start to protect the inverter and circuit breakes
Nope. Runs straight off battery. And load is not huge and seems to ramp up.