MABRU...worth the hype?

[TPG]

Looking at installing some new air con units and hear a lot about Mabru 12V DC units.

They look really efficient, and I get the allure of that. But there's a great deal of hype - and they are conveniently out of stock but will gladly take your pre-payment up front.

Am working on trying to figure out how much less efficient a traditional AC powered system is by comparison, but having an issue with the conversion.

Looking at a system that draws 5.7amps 120V AC and I have it figured at 684 watts, which is less than what some of the AC powered items in my galley draw. I have a very robust solar/lifepo4 system that easily provided enough juice to my Victron 3kw inverter.

Ideas?

[The Yacht Rigger]

We've sold many many Mabru units, and continue to do so. They are hard to beat in terms of efficiency, and their customer service is second to none. Nick really stands behind his products.
We're planning an in depth analysis video comparing various DC units and variable speed units - will be posting it on our Youtube channel (The On Deck Channel) as soon as we get it done.
Feel free to use the contact us section on our website if you have any follow up questions and one of our team experts will get back to you.

[FlyingScot]

First you need to compare apples to apples. Meaning, count the entire power consumption that comes from your DC supply (batteries/solar).
We have two Mabru 12v units that we bought from The Yacht Rigger. I'm glad we did! Both are DC12V 12K btu/hr units. Running both at maximum cooling, maximum fan speed combined they draw right at 90A from our 12v nominal LiFePO4 bank.
This inludes the seawater pump.

So when you make your comparisons, be sure to include the seawater pump and any inverter losses. The pump will be 50-200w and the inverter losses will be 6-7% at an absolute minimum and can be much higher depending on what part of the efficiency curve your load ends up being. Your Multiplus 3KVA is 93.9% @ 800W, 91.5% @ 1600W, 88.3% @ 2500W.

Remember, you'll pay for efficiency one way or the other. More solar and batteries if you use more energy. Boats only hold so much solar.

There are other advantages too, like no wear and tear on your inverter. You don't have to turn off aircon to run your galley device, etc.

[Straightahead]

Originally Posted by FlyingScot

First you need to compare apples to apples. Meaning, count the entire power consumption that comes from your DC supply (batteries/solar).
We have two Mabru 12v units that we bought from The Yacht Rigger. I'm glad we did! Both are DC12V 12K btu/hr units. Running both at maximum cooling, maximum fan speed combined they draw right at 90A from our 12v nominal LiFePO4 bank.
This inludes the seawater pump.

So when you make your comparisons, be sure to include the seawater pump and any inverter losses. The pump will be 50-200w and the inverter losses will be 6-7% at an absolute minimum and can be much higher depending on what part of the efficiency curve your load ends up being. Your Multiplus 3KVA is 93.9% @ 800W, 91.5% @ 1600W, 88.3% @ 2500W.

Remember, you'll pay for efficiency one way or the other. More solar and batteries if you use more energy. Boats only hold so much solar.

There are other advantages too, like no wear and tear on your inverter. You don't have to turn off aircon to run your galley device, etc.

Thanks for the insight Flying Scott. How do you think the Mabru 12,000 Btu/hr would work in the salon of a slightly larger cat?

[FlyingScot]

Originally Posted by Straightahead

Thanks for the insight Flying Scott. How do you think the Mabru 12,000 Btu/hr would work in the salon of a slightly larger cat?

I would always look at what the factory installs. Rarely (if ever) do they over specify an item.
Leopard 40 (First Generation) originally came with 12k btu/hr and after a couple of years they increased to 16k units. Presumably people wanted more cooling capacity.

We have no issue with our 12k units. If 16k units were available we would have probably bougth those just to have a faster cooldown. But no regrets, we don't need/want 21c temperatures. 27-28c is very comfortable for us.

[malabarmcgyver]

I am ordering a Mabru unit today. Our Dometic unit has a leak. I have been following Mabru for a few years and I think they are ahead of other manufacturers on build quality and efficiency. I assumed that when I replaced this 120v unit that I would replace it with a DC unit, but since it is prewired 120vac, I am sticking with that. Mabru has also been out of the 12V 5000BTU units for some time and finally they are a couple of grand more expensive.