Thanks for putting this together. It’s one thing to see claims posted on a forum, but seeing side by side proof of 120ac vs 12dc is ultimately all that matters. In the end, if it pulls 40 amps and my boat is cold, then nothing else matters.
Sounds too good to be true! Inverters are usually 90% plus efficient, so aside from the inverter is the 12v unit really 3x more efficient than the 115V version or is it just that it's putting out (absorbing) less BTUs? EER=29 really? What I would have like to see with this comparison is the flow rate and temperature change of the cooling water for each unit - this is an easy way to know the real BTUs Q=mc delta T. If it's true, I would buy one!
I'm interested in mounting one of these units in an RV to have ac and heat with remote control. Does the unit consume water in use (requiring constant water intake) or would using a radiator be enough to keep the system operating?
Can this be installed in a semi truck? I have a unit in my bunk that runs off the compressor but looking to replace it with an electric unit. Maybe I’d have to install more batteries so it won’t completely drain them
Quite impressive efficiency! Does your test amp draw on the DC unit include the amp draw from the 12v sea water pumps as well? How many amps does the 12v sea water pump draw?
I appreciate the video as it proves that sustainable A/C is possible on DC. Do you have aspirations or capability to use 48 VDC compressors? I currently have an electric powered catamaran and would like to use the 48 VDC propulsion banks for A/C when anchored. I could use a step down converter for 12 volts, but I would rather use the 48 VDC in order to use smaller gauge wiring and negate a step down converter.
Jeff, We do not currently have a 48V system in development. We are currently working on a larger 24v system but it is still under development and expect to release it early 2022. We have not had sufficient demand to warrant a redesign to a 48v system as of yet
Good video! This may be a stupid question but does a 12k btu 12 volt remove heat in room as fast as the 115 volt? I know in my car the 12 volt AC unit is affected by the rpms of the motor
Not a stupid question at all. Automotive ac isn't 12v but actually belt driven which is why your ac will work better at higher RPMS (belt is turning faster) the blower portion is 12v. Our unit is completely 12v so there is no relation between engine speed vs cooling capacity of the unit, same as 115v.
Hello, I have a 115 Volt AC Pioneer mini-split in my tiny house and it can be used for cooling and heating. Can a DC unit also be used for heating and cooling OR is it just for air-conditioning? I am just trying to learn which system would be better (AC vs. DC) when going off grid, using solar panels and batteries. I will also be doing a van conversion in future and looking for a very small air-conditioning unit. Thanks
Our units are all reverse cycle so they have heat but as crouton said, this particular unit was designed to be used on boats so it is water cooled. We have an air cooled option in the works but it is still in the developmental stage.
I like your AC and heating system, but I think we need another round of testing here. It doesn't seem correct that a 120v AC unit would use 3x the energy as a similarly designed 12v DC unit
The similarities are only in the appearance. The 12v unit utilizes a twin rotor, variable speed compressor and a PM DC blower. Just the change in blower consumption alone is about 10A. What else would you like to see as far as data on future tests?
Something is not right. If you dived 12,000btu/414w you get an EER rating of around 29 for the 12v unit. That is too high to be believable. Is there something I don't understand?
@@boatrx Have you done an install of a Marbu DC system yet and checked the EER? Would love to see that. I've seen your Termodinamica videos. They loo good but16K is too big for my boat.
@@boatrx I have a mini split system in my garage (220 volt) that is variable capacity and it kicks the pants off of my whole house AC unit which is not variable capacity. I don't need expensive test equipment to tell the difference, my electricity bill is the evidence. The variable capacity technology really is a game changer.
Sorry, just checking. So, the conclusion was that the 12 volt DC compressor (because of lower current draw & no in- rush current) is better than the 115 volt AC. Yes??? Thanks
I really didn’t understand what you try to present. 12k BTU is 3,51kw no matter it is connected to 115vca or 12vdc. Inrush current exist in both cases. By using a inverter you must add its energy consumption. You can add softstarters to reduces inrush’s current if this is the problem.
The point of this video was to clear up that exact misconception. 12,000 BTU running on 12v with new DC technology is vastly more efficient than 12,000 BTU 115v running though an inverter. The Running amps are in the video as well as inrush amps. Startup on 12v unit can be viewed at 7:00 in the video vs over 300A startup on 115v @ 12v viewed at 4:40 in video.
Mabru Power Systems, INC sorry but something is confuse. The 300A is in 12vdc, right? This is ok since 12kBTU means 3.6kw. Inrush current is very short in time to be caught by regular instruments, you must have a special one. Thanks
@@alcibiadesmarcialneto922 326A inrush was for the 115v unit running though an inverter @12v. The inverter display was able to pick up the current spike when the compressor kicked on but yes, we do have some very specialized testing equipment to properly test and develop our systems
Alcibiades, 12k BTU is 3,5 KW if you are just converting units of BTU to KW. For example, if this were an electrical resistance heater, it would take 3.5KW of electricity to create 12k BTU of heat. However, I think your misunderstanding is that an air conditioner does not just eliminate heat. It moves it. In the case of these marine air conditioners, they are moving heat out of the room and into the seawater via a water cooled condenser. So on his 12v unit, he is using about 450 watts of power to move a nominal 12k btu/hr of heat out of the air in the room and into the water circuit. This heat is not being created, or eliminated. Only moved from one place to another. That is the magic of air conditioning!
I can assure you that an inverter pulls much more than an amp in conversion from 115v to 12v but there is also a massive efficiency difference with our 12v units
The spec sheet online shows 17A @ 230v www.frigomar.com/en/products/single-phase-chiller-unit-inverter-bldc/ unless you mean running it in eco mode which would not produce 70,000BTU. In addition, you are not counting the raw water pump and the circulation pump that need to be running which draw at least 3A each and the air handler(s) that are distributing the air.
I don’t understand your comment. Are you saying that you do not believe that a 12,000BTU 115v unit running off of an inverter will draw 100A at 12v? I can assure you that I do in fact know what I am talking about and would be glad to answer any questions that you have.
