12 volt AC unit

[Steve Hunt]

Anyone have any experience with this brand of AC? It's a 12volt with a 14"x14" roof hole which seems to be rare on 12v units for some reason.

https://dcpowersales.com/products-2/b-cool12000rm-rv/

 

[posplayr]

If you search on Amazon or Aliexpress you will find a growing number of lower-power (600--800 watts) 12V models. PRices have been dropping close to $1-1.3K

Most of the ones that are direct from China will need to be charged (freon). Those you can order domestically are more likely to be already charged.

This is a cheap DIY model

https://www.amazon.com/Universal-el...cphy=9051700&hvtargid=pla-1617615080874&psc=1

This is an integrated unit which costs more.

https://www.amazon.com/Conditioner-...cphy=9051700&hvtargid=pla-1748908273191&psc=1


This integrated unit is 300-800W
https://www.amazon.com/RV65F-Universal-conditioner-agricultural-construction/dp/B0B3BQV177

 

[posplayr]

This is a Treeligo brand you can order direct from AliExpress $800 shipped or for about $1260 from Amazon. With Amazon, you can buy 3-4 years of insurance.

https://www.amazon.com/dp/B09WMNQ5L...jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==

900 watts 30-70 amps and minimum recommended battery of 200 Amp-hr




https://www.aliexpress.us/item/3256...1587225&gatewayAdapt=glo2usa&_randl_shipto=US

 

[Steve Hunt]

Anyone have any experience with this brand of AC? It's a 12volt with a 14"x14" roof hole which seems to be rare on 12v units for some reason.

https://dcpowersales.com/products-2/b-cool12000rm-rv/

Looks like Thompson Tractor, the Caterpillar dealer, is their distributor for Alabama. So that is a good sign.
Well that never happens for me, they have a Florida distributor in Jacksonville, I'll go over there and take a look this week.

 

[Steve Hunt]

My primary draw to the DC air conditioner is for lunch stops and the like (1hr or less) and the overall noise or lack off. According to the spec sheets the DC air conditioners are considerably more quiet. The thing i don't 100% know is if sleeping with the DC air conditioner running and also plugged into shore power...when my 200 amp hr of Lithium runs low does the inverter/charger just simply start charging the batteries before they run completely out and so I won't really know anything is happening, the air conditioner just keeps running uninterrupted ? If so then the only downside i see on a DC air conditioner is the initial cost. Am i missing anything?

 

[posplayr]

On the compressor look for a "scroll type variable frequency". I have never tested one but the variable frequency implies a solid-state inverter that can drive at higher or lower frequencies where power output is proportional to frequency.

In contrast, from my testing with a typical house/window AC unit (5000 BTU), the power (using a Kilowatt meter) pretty much stays the same regardless of fan speed. I presume that power consumption is dominated by the compressor that is constan6t/synchronized to the 60 hz AC.

 

[posplayr]

My primary draw to the DC air conditioner is for lunch stops and the like (1hr or less) and the overall noise or lack off. According to the spec sheets the DC air conditioners are considerably more quiet. The thing i don't 100% know is if sleeping with the DC air conditioner running and also plugged into shore power...when my 200 amp hr of Lithium runs low does the inverter/charger just simply start charging the batteries before they run completely out and so I won't really know anything is happening, the air conditioner just keeps running uninterrupted ? If so then the only downside i see on a DC air conditioner is the initial cost. Am i missing anything?

The lowest specs I have seen are 30-80A (presumably Low/Hi)for the 12V AC Units. So if you have a big enough 120VAC to 12V DC battery charger then you can run continuously all night.

In not, but your batteries are fully charged by evening, you can probably last most of the night between your 200 Amp-hrs stored and the additional charging current coming from a Shore power DC Charging.

Considering only stored battery power, If you can run the AC unit at 30 amps (on Low) then you have 200/30*80%=5.3 Hours of run time. At that point, even just an additional 20 amp charging from shore power should get you through the night. 8 hours (overnight) @ 20 amps is an additional 160 Amp-hrs which is again 5.3 hours compared to the stored battery power.

 

[Steve Hunt]

The lowest specs I have seen are 30-80A (presumably Low/Hi)for the 12V AC Units. So if you have a big enough 120VAC to 12V DC battery charger then you can run continuously all night.

In not, but your batteries are fully charged by evening, you can probably last most of the night between your 200 Amp-hrs stored and the additional charging current coming from a Shore power DC Charging.

Considering only stored battery power, If you can run the AC unit at 30 amps (on Low) then you have 200/30*80%=5.3 Hours of run time. At that point, even just an additional 20 amp charging from shore power should get you through the night. 8 hours (overnight) @ 20 amps is an additional 160 Amp-hrs which is again 5.3 hours compared to the stored battery power.

That’s great info/summary. Mine is a 2000w Renogy inverter/charger. The spec sheet says 5-65 amps dc charge current. What is the 80% in your example? assumed max out of my batteries?

 

[posplayr]

That’s great info/summary. Mine is a 2000w Renogy inverter/charger. The spec sheet says 5-65 amps dc charge current. What is the 80% in your example? assumed max out of my batteries?

That is an interesting device. It seems more like a UPS that any RV-type device I have seen. It looks like it is what is called "Double Conversion". That basically means that AC input is converted to DC to charge a battery bank and that same battery is used for power into a DC-to-AC inverter. The other topology is called line-interactive. It doesn't have this strict (double conversion) separation between AC->DC and DC->AC .

This provides essentially total isolation between AC in and AC out. This is probably why you are not sure what is going on when you run the AC all night

https://www.eaton.com/us/en-us/prod...rent UPS design,, line-interactive and online.


It looks like you also have a DC-DC On-Board battery Charger with MPPT; is that correct? So you in addition to the unit above you connect direct to the battery as well for DC loads and Alternator/ Solar charging. That is a quiet capable setup in only two devices. I don't remember but doesn't that DC-DC also back charge to the start battery if it is low?

>>>What is the 80% in your example? assumed max out of my batteries?

Yes this assumes Lithium and 80% effective depth of charge (90%->10%) vs. 50% for lead Acid.

It seems you could go either way (AC AirCon or DC AirCon). If you want the off-grid capability and what is probably quieter operation then I would go with the 12V AirCon. The double conversion (if true) essentially means you should have no startup overload issues.

Most of the 12V ACon units are less than 1000W and you can run any combination of shore power or generator and the Battery to AC Out conversion essentially isolates your AirCon from the course especially if you are using Lithium (super low impedance).

I don't have any first-hand experience with either of these devices just reading the manual and I'm an aerospace EE.

 

[Steve Hunt]

That is an interesting device. It seems more like a UPS that any RV-type device I have seen. It looks like it is what is called "Double Conversion". That basically means that AC input is converted to DC to charge a battery bank and that same battery is used for power into a DC-to-AC inverter. The other topology is called line-interactive. It doesn't have this strict (double conversion) separation between AC->DC and DC->AC .

This provides essentially total isolation between AC in and AC out. This is probably why you are not sure what is going on when you run the AC all night

https://www.eaton.com/us/en-us/prod...rent UPS design,, line-interactive and online.


It looks like you also have a DC-DC On-Board battery Charger with MPPT; is that correct? So you in addition to the unit above you connect direct to the battery as well for DC loads and Alternator/ Solar charging. That is a quiet capable setup in only two devices. I don't remember but doesn't that DC-DC also back charge to the start battery if it is low?

>>>What is the 80% in your example? assumed max out of my batteries?

Yes this assumes Lithium and 80% effective depth of charge (90%->10%) vs. 50% for lead Acid.

It seems you could go either way (AC AirCon or DC AirCon). If you want the off-grid capability and what is probably quieter operation then I would go with the 12V AirCon. The double conversion (if true) essentially means you should have no startup overload issues.

Most of the 12V ACon units are less than 1000W and you can run any combination of shore power or generator and the Battery to AC Out conversion essentially isolates your AirCon from the course especially if you are using Lithium (super low impedance).

I don't have any first-hand experience with either of these devices just reading the manual and I'm an aerospace EE.

Yes the other device is a Renogy 50A DC to DC charger with MPPT. I don't have any solar but wanted to go ahead and be able to add it in the future. I suppose I may change my mind but at this point it's pretty distant on my projects list. Trying to make a decision on AC or DC air cond has made it to the top of the list. My biggest issue right now is any experience to confidently make the decision on the Air conditioning. It's got to happen though, it's impossible to sleep in the Southeast when ambient is a low of 78 and 90% humidity. Thanks for your input, very helpful.

 

[posplayr]

My biggest issue right now is any experience to confidently make the decision on the Air conditioning.

I just compared the noise spec for the 120VAC AirCon vs a 12VDC AirCon. Two 12V units claimed 22 and 28 db noise levels whereas the Recon below is listed at 65 db .

Note a 40 db difference is 1000 times the noise level on a linear scale. If this is true the 12V units are going to whisper quiet compared to the 120VAC units. It is not really a comparison.


https://www.amazon.com/RecPro-Conditioner-110-120V-Non-Ducted-Installation/dp/B0B237WDG3?th=1


If you figure to run a loud generator anyway, then maybe a loud compressor doesn't matter in the scheme of things. But if you want to sleep at night off shore power or battery power, then the 12/24VDC seems to be the way to go. Not sure why there is much to debate.

 

[Steve Hunt]

I just compared the noise spec for the 120VAC AirCon vs a 12VDC AirCon. Two 12V units claimed 22 and 28 db noise levels whereas the Recon below is listed at 65 db .

Note a 40 db difference is 1000 times the noise level on a linear scale. If this is true the 12V units are going to whisper quiet compared to the 120VAC units. It is not really a comparison.


https://www.amazon.com/RecPro-Conditioner-110-120V-Non-Ducted-Installation/dp/B0B237WDG3?th=1


If you figure to run a loud generator anyway, then maybe a loud compressor doesn't matter in the scheme of things. But if you want to sleep at night off shore power or battery power, then the 12/24VDC seems to be the way to go. Not sure why there is much to debate.

Just trying to uncover as much as possible...don't know what i don't know...I get tired of being disappointed by some functionality or lack of that is never told in spec sheets or general research but found out after you spend $thousands. I'm headed over to a distributor of it today, we'll see what I learn. Hopefully they have a functioning unit and a knowledgeable person. 22-28 db is highly unlikely, not to mention ambient db will be lucky to be 50ish

 

[posplayr]

Just trying to uncover as much as possible...don't know what i don't know...I get tired of being disappointed by some functionality or lack of that is never told in spec sheets or general research but found out after you spend $thousands. I'm headed over to a distributor of it today, we'll see what I learn. Hopefully they have a functioning unit and a knowledgeable person. 22-28 db is highly unlikely, not to mention ambient db will be lucky to be 50ish

If you can find a working demo that is always best.

Please confirm whether or not this is the new variable frequency scroll type compressor.

Here is a video doing a review of various 12VDC AirCons. The US name-branded ones are double ($1600 to $4300) the Chinese offerings and they probably come from the same place.

Based on specs, this is going to be more efficient than the 120VAC units and with the inverter you have you will not be suffering an (12V to 120VAC conversion loss). So you could be up to 30% ahead of the game with the 12VDC units in terms of battery Amp-hr utilization efficiency. If the units have an actual "low" mode and can 1/2 the current draw then they are potentially even more efficient. You might consider taking a kilowatt meter to measure the AC draw (if that is the source) or a DC Current Amp. They are not too expensive if you don't have one.

So based on noise level and efficiency, the 12VDC unit (on paper) is a no-brainer.

The benefit of the Chinese units is that there are multiple vendors and even manufacturers of very similar if not the same basic unit. It would appear as if there was government support to produce a highly efficient unit that multiple manufacturers produce. In the US you would tend to have much more diversity until the marketplace gets very mature.

Of course, dropping $1300 for one warrants all due diligence.

 

[posplayr]

Here is another Treeligo unit rated at 15000 BTU 30-70 amps 3 speeds with variable frequency (does not mention scroll type) compressor only $850 .

Prices are obviously all over the map. I just heard on a related topic, that a dual zone mini split costs about $2100 at the local Home Depot but 5 hours below the border in Mexico they are about $500.




https://www.ebay.com/itm/3945068316...iayb0kXQxcI3Yg%3D%3D|ampid:PL_CLK|clp:2047675

 

[landcruisin-SMB]

I'm just not a fan of adding these to the roof. I'd much rather do a split system and hang the condenser somewhere out of the way. The issue is that anywhere under the van is going to plug up the coil with mud/dirt/etc. Been thinking about hanging one on the back of the high top, open to any other creative ideas too though.

Also pretty wild that some of these in this price bracket seem to be heat pumps too. Neat stuff.

 

[posplayr]

I'm just not a fan of adding these to the roof. I'd much rather do a split system and hang the condenser somewhere out of the way.

I agree with a Class C proper RV especially if you have a rear bedroom suite. You also have a lot more room for boosting solar to 600+ watts. On the other hand, in a van, separating the condenser from the head units just seems to take up too much room. Adding 75 lbs to the roof is not my favorite thing either, but it would seem to take up the least real estate in a space-challenged van application.

I have a raised fiberglass top with a 1"x3" steel support structure also including a reinforcement around the 14"x14" rear opening. So the weight is not much concern for me. In my mind, this is much better than drip rail-mounted racks and some type of oversized rooftop carrier.

Of course, rooftop air on a pop-to would not work very well, and the mini-split might be a better option. There are 12VDC A/C units that are separated (as a mini-split) and usually even cheaper than the integrated rooftop units

https://www.ebay.com/itm/255133990729

 

[landcruisin-SMB]

I missed the part where they are 75 lbs. That's definitely a no go on top of an already high roof.

I bet you could do a hinged sealed box somewhere bolted to the frame/underbody. Pop open the hinge when it's running, close it when it's not. Add some rubber or spring isolators, and away you go.

Hmmm, this might be viable. And unlike the handheld ones that seem to be meant for tents, it'd actually provide cooling.

 

[posplayr]

I missed the part where they are 75 lbs. That's definitely a no go on top of an already high roof.

I was doing a quick comparison of specs of 120VAC vs 12VDC AirCon units in the 13500 BTU range and they all seemed to be about 75 lbs.

If you are running oversized tires and have moved the spare to the rear bumper you do have quite a bit of space to play with.

There is another member here that did a Chinese Aircon where he mounted the condenser unit underneath so it has been done. I don't think he enclosed the unit but may not be doing too much off-road mudding either.

https://www.sportsmobileforum.com/f...-12v-split-unit-ac-air-conditioner-30418.html

 

[posplayr]

Here is another Treeligo unit rated at 15000 BTU 30-70 amps 3 speeds with variable frequency (does not mention scroll type) compressor only $850 .

Prices are obviously all over the map. I just heard on a related topic, that a dual zone mini split costs about $2100 at the local Home Depot but 5 hours below the border in Mexico they are about $500.




https://www.ebay.com/itm/3945068316...iayb0kXQxcI3Yg%3D%3D|ampid:PL_CLK|clp:2047675

The add lists this unit to have a height of only 6.25" (159mm). Some of the pictures show an additional gap so there may be a couple more inches.

 

[Wowbagger]

My condenser is on the bottom of the van, and I've never had issues with it getting plugged up with dirt. True, I don't drive through deep mud, but I don't shy away from dirt roads either.