Marine 12v air conditioning

[FlyingScot]

Well I finally hooked up both my my Mabru 12k btu/hr units. Set both to 17C to ensure full fan speed and maximum compressor speed. The water pumps are powered directly from each unit thus included in the following number.

Using my Fluke 365 clamp on meter, I measured between 90-91 amps combined for both. Approximately 600 watts each.

For those running AC driven units through an inverter, please account for the water pump in your comparisons.

Inverter losses can really add up. Victron Multiplus 24/3000/70 is most efficient around 800 watts and 93.9% efficiency. 91.5% at 1600 watts. It gets worse from there.


I'd say this is extremely efficient and I'm happy with the results.

[FlyingScot]

Originally Posted by Mrichardin

https://www.alibaba.com/product-deta...2ee24804Ku8jZJ

I am getting a quote 12V DC for 2x 7000BTU and 1x 12000BTU (including 3x strainer and DC12V brushless water pump) for 4,300 USD shiiping to NZ included.

A slightly different link shows the 12k btu/hr model uses 960watts.

That's 60% more power than what I have measured and still not sure about the water pump on this model. If not add at least 50 more watts.

https://www.alibaba.com/product-deta...7b534ee83d23mI

[flee27]

I say this as a question and not a statement.

To me a unit like the Velair VSD unit still wins. You can run it in eco mode for minimal power usage but have the option of higher BTUs if wanted when there is more power available/hooked to shore power.

Maybe this idea is not reality. But in my planning I could cool my small sleeping qtrs in eco mode or open up more vents to cool other areas when the power was available.

The power demands still seem to be pretty equal all things factored in between the VSD units and the 12 votl units. The only win the 12 volt units seems to have is the lack of need/wear and tear on the invertor. Although I am not really sure how practical it is to talk about an invertor as a wear item.

Thanks for all the opinions and experiences. I like hearing them

Foster

[CaptainRivet]

Originally Posted by Mrichardin

By the way it seems that Dometic as filled a complain (only in the USA though, so not a real issue) against Mabru and HopeWell China for some tarrif breach:
https://www.federalregister.gov/docu...ublic-interest

So it seems to me that Dometic has indeed identified Hopewell as the Mabru factory.

Any feedback from people using the Hopewell DC air cond. ?

What Marbu is doing buying the honeywell unit and optimizing it. Like this they get a good base product but don't give away the knowhow for the last 10-20%.
So you pay for this optimization and their service.
The last 10% is always the most expensive.
You want perfect solution get Marbu, you want a 12V unit to cool down your owner to take the edge of on the very hot days a Chinese honeywell definitly is enough.

The higher power consumption of Chinese you could also balance/spend the difference on with more solar and more LFP bank, so when not running AC you have more overall.
3 units for 5300 while one Marbu cost more than that. If i depend on Aircon thats worth it, if not the Chinese are good enough that Marbu buys them as base product....

[CaptainRivet]

Originally Posted by FlyingScot

Well I finally hooked up both my my Mabru 12k btu/hr units. Set both to 17C to ensure full fan speed and maximum compressor speed. The water pumps are powered directly from each unit thus included in the following number.

Using my Fluke 365 clamp on meter, I measured between 90-91 amps combined for both. Approximately 600 watts each.

For those running AC driven units through an inverter, please account for the water pump in your comparisons.

Inverter losses can really add up. Victron Multiplus 24/3000/70 is most efficient around 800 watts and 93.9% efficiency. 91.5% at 1600 watts. It gets worse from there.


I'd say this is extremely efficient and I'm happy with the results.

Where did you find the efficency of the multiplus at different loads?

[FlyingScot]

Originally Posted by CaptainRivet

Where did you find the efficency of the multiplus at different loads?

From a Victron PDF, you can download/view it here. Page 3 to be exact.
https://www.victronenergy.com/upload...efficiency.pdf

[mvweebles]

Originally Posted by CaptainRivet

What Marbu is doing buying the honeywell unit and optimizing it. Like this they get a good base product but don't give away the knowhow for the last 10-20%.
So you pay for this optimization and their service.
The last 10% is always the most expensive.
You want perfect solution get Marbu, you want a 12V unit to cool down your owner to take the edge of on the very hot days a Chinese honeywell definitly is enough.

The higher power consumption of Chinese you could also balance/spend the difference on with more solar and more LFP bank, so when not running AC you have more overall.
3 units for 5300 while one Marbu cost more than that. If i depend on Aircon thats worth it, if not the Chinese are good enough that Marbu buys them as base product....

So what exactly does Mabru do to 'optimize' the base Chinese system and make it more efficient? Platitudes like "last 10% is always the most expensive" are great, but wondering about the actual engineering changes to deliver the 'last 10%'

[CaptainRivet]

Originally Posted by mvweebles

So what exactly does Mabru do to 'optimize' the base Chinese system and make it more efficient? Platitudes like "last 10% is always the most expensive" are great, but wondering about the actual engineering changes to deliver the 'last 10%'

If i would know in detail i would build and sell myself "Marbu ACs" for the rum kitty...
You can buy each a unit and dismantle to figure out the actual differences.
Here you have an indication:
Our evaporators are copper rather than aluminum and our condensers are 1 piece B30 rather than the likely max B10 on that unit.
Freon replaced with ???.
Most liky more efficent pumps.

Good for you to know the Chinese Honeywell is good enough as working base product, so for more then half the price good the quality i get is enough for me. Can live with a bit a higher draw and add 1 more solar panel+MPPT to compensate for it. Good is if honeywell is not selling replacement parts you can order replacement parts at Marbu and they will fit and if the "right" parts make it better but at least fix it. What do you want more from a unit thats less then half the price from China, won't get any better....

[CaptainRivet]

Originally Posted by FlyingScot

From a Victron PDF, you can download/view it here. Page 3 to be exact.
https://www.victronenergy.com/upload...efficiency.pdf

Thanks.
Thats a massive derating...well Victron Squeezes the lemon and give you as high as possible rating at 25C. I have Studer innotect inverter/charger developped and build in switzerland with military grade pcbs lying at my parents waiting for install to replace the Victrons. they are real LF and not hybrid like victron hand keep their rating 3000W continous/3500W for 30min/9000W peak for 30 sek straight from -20 till +55 degrees C. Their 2 torrodial transformers from the XTM 24/3500 is exactly the same as the two in the 24/5000 Quattro and Multi. They have the same features like Victrons, 10 years warranty but you only need their remote control which is 180Euro for full programming and adjusting. No dongles, Adapter cables, windows PC...to get them adjusted.

[FlyingScot]

Originally Posted by CaptainRivet

If i would know in detail i would build and sell myself "Marbu ACs" for the rum kitty...
You can buy each a unit and dismantle to figure out the actual differences.
Here you have an indication:
Our evaporators are copper rather than aluminum and our condensers are 1 piece B30 rather than the likely max B10 on that unit.
Freon replaced with ???.
Most liky more efficent pumps.

Good for you to know the Chinese Honeywell is good enough as working base product, so for more then half the price good the quality i get is enough for me. Can live with a bit a higher draw and add 1 more solar panel+MPPT to compensate for it. Good is if honeywell is not selling replacement parts you can order replacement parts at Marbu and they will fit and if the "right" parts make it better but at least fix it. What do you want more from a unit thats less then half the price from China, won't get any better....

I can't wait for you to get them and share your results. The more we know the better.

I suspect your 10-20% is off by quite a bit. I think they will use 30-50% more power once you throw in the loss through your inverter and the sea water cooling pump. Based upon that one link I posted earlier, you may even see 60-70% more power consumption. Time will tell.

The concept of adding more panels is a good idea, right up until you run out of room to add more panels. We currently have 5 x 435Wp LG BiFacials hanging off the arch and 2 x 360Wp LG NeonR on the hard top. 5 x 100/50 MPPTs and 2 x 100/30 MPPTs. All tied into a Cerbo. All Victron setup means we are sticking with their inverters as well. Victron batteries, Lynx Train (BMS, Power In and 2 x Distrubitors). Dual Multiplus 12/3000/120-50. Smaller Phoenix Inverter 800VA and a seperate Victron 50A charger.
I can't see adding any more panels for our boat. It's already significant weight, windage and surface area.

[FlyingScot]

Originally Posted by CaptainRivet

Thanks.
Thats a massive derating...well Victron Squeezes the lemon and give you as high as possible rating at 25C. I have Studer innotect inverter/charger developped and build in switzerland with military grade pcbs lying at my parents waiting for install to replace the Victrons. they are real LF and not hybrid like victron hand keep their rating 3000W continous/3500W for 30min/9000W peak for 30 sek straight from -20 till +55 degrees C. Their 2 torrodial transformers from the XTM 24/3500 is exactly the same as the two in the 24/5000 Quattro and Multi. They have the same features like Victrons, 10 years warranty but you only need their remote control which is 180Euro for full programming and adjusting. No dongles, Adapter cables, windows PC...to get them adjusted.

It's not the temperature rating reduction I was speaking about. It's the efficiency. All inverters are less than 100%. Depending on load they lose 6-13% under typical conditions. Very light loads even more. Over loaded WAY more.

I don't know which model you are buying, but the only information I could find says Studer-Innotec max efficiency is for 24V is 94%. I suspect the curve is very similar to the Victron link I posted.


Adding:
Are you sure about that continous ratings up to 55C?
The spec sheet on XTM3500 says @ 25C.
https://studer-innotec.com/wp-conten...der_A4-WEB.pdf

[CaptainRivet]

Originally Posted by FlyingScot

I can't wait for you to get them and share your results. The more we know the better.

I suspect your 10-20% is off by quite a bit. I think they will use 30-50% more power once you throw in the loss through your inverter and the sea water cooling pump. Based upon that one link I posted earlier, you may even see 60-70% more power consumption. Time will tell.

The concept of adding more panels is a good idea, right up until you run out of room to add more panels. We currently have 5 x 435Wp LG BiFacials hanging off the arch and 2 x 360Wp LG NeonR on the hard top. 5 x 100/50 MPPTs and 2 x 100/30 MPPTs. All tied into a Cerbo. All Victron setup means we are sticking with their inverters as well. Victron batteries, Lynx Train (BMS, Power In and 2 x Distrubitors). Dual Multiplus 12/3000/120-50. Smaller Phoenix Inverter 800VA and a seperate Victron 50A charger.
I can't see adding any more panels for our boat. It's already significant weight, windage and surface area.

They are 12/24V units so no inverter losses and from data you are somewhere between 10-30% more. And i just need 1 maybe a 7000BTU for my owners cabin to cut the edge on the really hot days (or to dehumify) where i cannot sleep on deck in the hamoc due moskitos eat you alive...not a friend off AC

[CaptainRivet]

Originally Posted by FlyingScot

It's not the temperature rating reduction I was speaking about. It's the efficiency. All inverters are less than 100%. Depending on load they lose 6-13% under typical conditions. Very light loads even more. Over loaded WAY more.

I don't know which model you are buying, but the only information I could find says Studer-Innotec max efficiency is for 24V is 94%. I suspect the curve is very similar to the Victron link I posted.

I got 2x studer extender XTM 24-3500, one will do it 99% of time and 2nd is working spare. Have real 6kw cont/7kw for 30min and 18kw peak, will never get into overload with them.
Yes they are 94% but at 3000W not VA but their efficiency curve is more flat as rating kept -20 till 55 C. massivly oversized just their torodial trafos are 1500W more then Victron on same rating, real standby only 18W compared to 45W Victron...
Victron is loosing a lot market share to Studer in Europe and had to extend their waranty to 10years due to Studer...they are the benchmark since some years now.

[CaptainRivet]

How are the LG bifacials? How much watts/amps do you get out of them?
Have 3x365W Longli bifacials on davits and they do 440W regularly. Will change arch soon and them plan to add 3x550W Longli bifacials on arch and 2x longli 365W go on top of soft bimini

[FlyingScot]

Originally Posted by CaptainRivet

How are the LG bifacials? How much watts/amps do you get out of them?
Have 3x365W Longli bifacials on davits and they do 440W regularly. Will change arch soon and them plan to add 3x550W Longli bifacials on arch and 2x longli 365W go on top of soft bimini

I'll move over to another thread you started to discuss the Studer-Innotec inverters as I can't find much to support your conclusions.
https://www.cruisersforum.com/forums...ml#post3728765

As far as the panels my setup has generated 15KwH in a single day so far.
Very few opportunities to hit records since my battery bank gets full. It's 1320AH.
I've seen over 200A charging + house loads.
My 360 NeonR hit over 430w each, but that is not common.
My 435 bifacials always hit above rating. I'm sure I haven't seen their highest yet, but each has hit 20%+.

Peak ratings are fun to talk about but harvest is everything.