Help!! AC for a cargo trailer- still confused.. Ecoflow delta pro?

[gooby]

I have a 16' cargo trailer. I would like to run a 6000 BTU window AC on eco mode. Presumably this is gonna be around 500 watts. I was going to buy an Ecoflow Delta Pro + spare battery (7.2kwh) for a total of about $5000. Plus the solar panels. Not cheap.. to say the least.

I do not need anything more than a few lights, chargers, and a fridge powered, besides the option to have air conditioning. Maybe an occasional hair trimmer or such. I plan on driving cross country and want to make sure I have the option for AC if I get caught in hot weather and can't find shore power. I have a medical condition that makes too much heat intolerable.

Should I be investing all this money just for the option of having AC? Or am I crazy. I genuinely could get by with a sub $1500 setup if it weren't for the AC debacle. Any tips would be appreciated. Should I be looking at other cooling methods instead of a really big battery/solar system? I would want the option to have AC running throughout the night, so like 12 hours. Thanks.

 

[NGNERD]

I think 500 [watts] per hour on the AC would require 500/12= 41.66 amps on the DC side, that is per hour, at 12 hours that should be 499.2 amp hours. The delta pro is 7200 watt hours or 600 amp hours, that is cutting it close and not counting effeceincy of the delta pro.
I would consider a generator if possible, if not, build my own bank, Will has good videos on this. Just my opinion, not a pro at this.
Also, consider a Max Air fan on the roof of that trailer, it would draw a lot of that heat out, these can be ran in the rain with the cover. Thanks

 

[Al D]

Remember that the AC isn't probably going to run all 12 hours straight. How well insulated is the trailer?

 

[gooby]

Remember that the AC isn't probably going to run all 12 hours straight. How well insulated is the trailer?

Not very. Insulation job is not great and it's only 1" thick walls. I could redo all of it to be done better and zero gaps and XPS, but it's really not thick enough imo. I should have ordered thicker walls.

 

[Al D]

If you're going to spend money on conditioning the air, it's best placed in insulation first.

Your trailer looks fairly straight edged so it shouldn't be too difficult. My van, on the other hand, was a bit trickier to do with all the rounded sides and roof. I've got R-5 for just about everywhere in the van. If I do another van conversion, I think I'll go for R-10. You lose a couple inches on floor space (which is significant in a van), but I think it's worth it to be comfortable.

 

[gooby]

If you're going to spend money on conditioning the air, it's best placed in insulation first.

Your trailer looks fairly straight edged so it shouldn't be too difficult. My van, on the other hand, was a bit trickier to do with all the rounded sides and roof. I've got R-5 for just about everywhere in the van. If I do another van conversion, I think I'll go for R-10. You lose a couple inches on floor space (which is significant in a van), but I think it's worth it to be comfortable.

Yep, one big box. It's not too hard, but the manufacturer added some silicone caulk between the panel seams so I have to get that taken off, hopefully not too much damage done. Maybe a hair dryer will help there?

 

[NGNERD]

Not very. Insulation job is not great and it's only 1" thick walls. I could redo all of it to be done better and zero gaps and XPS, but it's really not thick enough imo. I should have ordered thicker walls.
View attachment 120577

Nice looking rig!! Did you build or who is manufacturer? As al noted, that a/c wouldn't roll continuously like I calculated, he made a good point

 

[gooby]

Nice looking rig!! Did you build or who is manufacturer? As al noted, that a/c wouldn't roll continuously like I calculated, he made a good point

Also, even my basic 6k btu unit has a "eco" mode. No clue how much better that is, but it's worth noting.

It's a manufacturer named Weeroll in FL. Wicked cool trailer, but I can't suggest them because the company is very scammy/shady in their practices. It's a shame because they are super cool products, and 100% aluminum. It's a 16 ft trailer from back to front and the entire frame is custom welded. I love it, but I wish the company were more straight. They forgot to do some things at the factory, I had to pay to have them fixed locally, and then they never paid me the money they promised for the repairs(that I paid for from the factory that they forgot!). I.e. the roof was unsealed and there was a hole in the rear left panel causing water intrusion.

At least it's 100% aluminum and thus some water isn't a problem.

 

[NGNERD]

Also, even my basic 6k btu unit has a "eco" mode. No clue how much better that is, but it's worth noting.

It's a manufacturer named Weeroll in FL. Wicked cool trailer, but I can't suggest them because the company is very scammy/shady in their practices. It's a shame because they are super cool products, and 100% aluminum. It's a 16 ft trailer from back to front and the entire frame is custom welded. I love it, but I wish the company were more straight. They forgot to do some things at the factory, I had to pay to have them fixed locally, and then they never paid me the money they promised for the repairs(that I paid for from the factory that they forgot!). I.e. the roof was unsealed and there was a hole in the rear left panel causing water intrusion.

At least it's 100% aluminum and thus some water isn't a problem.

Thanks for the heads up, will steer clear. Sounds like your gonna make it great though

 

[gooby]

$3k for 6072Wh https://www.bluettipower.com/products/ac300-b300
Might be worth considering this setup.

EDIT: nmd, I misinerpreteted, this is only 3Wh. Ecoflow is better.

 

[12VoltInstalls]

buy an Ecoflow Delta Pro + spare battery (7.2kwh) for a total of about $5000.

You could spend $5000 on components or aio and buy more panels than you fit for about twice the power as the egoflow

Remember that the AC isn't probably going to run all 12 hours straight. How well insulated is the trailer?

You should insulate with 2” or 1.5” polyiso imho

Ecoflow is better.

it is expensive for merely a convenience

 

[missingegg]

Chiming in late on this thread: The way to evaluate AC needs ahead of time is with an HVAC "Manual J" calculation. This is the standardized way to calculate the BTUs of cooling or heating needed by a building, taking into account the outdoor temperature and the amount of insulation in the walls. It's really intended for fixed buildings, but one can use it to get a reasonable estimate of the BTUs needed for an insulated trailer. There are some complexities in doing this calculation right, but for a simple rectangular "building", you can find free online calculators that will give you a reasonable result. This will let you see how the BTUs of cooling will change if you have better insulation, and assist in seeing the tradeoffs one can make with higher powered AC versus more insulation.

All that said, I've done this calculation for my cargo trailer, and it led me to install 3" R15 insulation everywhere, including ceiling and floor.

 

[12VoltInstalls]

I've done this calculation for my cargo trailer, and it led me to install 3" R15 insulation everywhere, including ceiling and floor

That’s an interesting observation.

More of a wildhat conclusion from observations, but I’ve said for years there’s a remarkable and noticeable difference from “R1” to R4 (think insulated glass low-E windows for example). However, I also think “the magic” starts about R10+ but seems more like magic over R13. R15 isn’t “fantastic” by the numbers pundits bandy about; though the difference from R15 to R30 is not nearly as remarkable imho

 

[missingegg]

That’s an interesting observation.

More of a wildhat conclusion from observations, but I’ve said for years there’s a remarkable and noticeable difference from “R1” to R4 (think insulated glass low-E windows for example). However, I also think “the magic” starts about R10+ but seems more like magic over R13. R15 isn’t “fantastic” by the numbers pundits bandy about; though the difference from R15 to R30 is not nearly as remarkable imho

Absolutely right, the heat transfer reduction at high R values starts to make incrementally smaller and smaller efficiency gains. When you're talking about a house, and the heating/cooling bills you might incur, very high R values can nevertheless make sense, as you're amortizing the cost of a highly insulated building across many years, and so even small reductions in energy bills can pay off.

For a trailer/RV, I think higher R values are worth it if you're trying to power AC with solar. Most people will be either very constrained on roof space for solar, so generating more power isn't easy. Or they'll use the trailer for a relatively small number of days each year, and the cost of an expensive solar system is relatively high per day of use.

 

[12VoltInstalls]

I think higher R values are worth it if you're trying to power AC with solar.

Yes. R15-R20 isn’t probably ’felt’ in the insulated environment but is noticeable in energy consumption. Often- at least with heating in cold weather climates- the difference between R6/7.5 and R13-R15 can be ‘felt’ in the environment with very noticeable reductions in energy requirements.

 

[gooby]

You could spend $5000 on components or aio and buy more panels than you fit for about twice the power as the egoflow

You should insulate with 2” or 1.5” polyiso imho

it is expensive for merely a convenience

Appreciate the input.

They do have the 3.8kw ecoflow delta pro on ebay refurb for $2175. I assume it's still not worth getting and I am better off with a full custom component setup?

Do you mind linking me to a good starting point?

I am going to look into the polyiso stuff, it is the highest R-value it seems. Unfortunately the way the walls are on, I would have to add in spacers for all the windows and doors given that the frame is only 1" thick. So it's going to be hard to go > 1".

BTW, is there any reason i should have a significant 'gap' in the walls or can I put in a full 1" insulation if the aluminum frames are just a hair wider than 1"?

 

[Al D]

The custom build will almost certainly be less expensive. I would go with a 24V system or higher. As for a starting point, I think the guy who started this forum, Will Prowse, has an e-book or something that goes over all this. Someone who knows more about that can chime in. He also has a YouTube channel that is pretty informative.

Leaving a gap between the insulation and the wall will have some insulating effect, but not as much as having more properly installed insulation. The 3/4 inch iso panels are the highest R value per inch due to the manufacturing process. However, the 1 inch panels will probably be better suited for your ~1 inch cavity. Face the foil side of the panels to the outdoors and ensure whatever gap is left over is between the wall and the foil side. This will create a [small] pocket of air that will net you just a little more insulation for no cost or comprise.

 

[12VoltInstalls]

I am better off with a full custom component setup?

Yup

Do you mind linking me to a good starting point

Well first confirm how many watts you need for consumption. Then look up the system plans from Will that suite your needs. That will save three pages of writing.

way the walls are on, I would have to add in spacers for all the windows and doors given that the frame is only 1" thick. So it's going to be hard to go > 1".

Not really. Most HDs and Lowes have 2x2 which is 1-1/2”. Use polyurethane caulking (strong adhesive) and pad all the walls out by screwing to the original structure. Use 1” and 1.5” foam board (or polyiso) and fit panels between the new ‘studs’ with a 3/8” space all the way around their perimeter and fill the gaps with “window and door” spray foam (this insures little to no chance of in-wall condensation from the heated or cooled space). Cover with your choice of wall finish plywood, paneling etc

BTW, is there any reason i should have a significant 'gap' in the walls or can I put in a full 1" insulation if the aluminum frames are just a hair wider than 1"?

Gap as in thickness isn’t an issue except that the double vapor barrier can create moisture against the skin if the envelope is not adequately sealed and the interior isn’t provided with an engineered means of creating planned air exchange to mitigate environmental humidity.

 

[missingegg]

Appreciate the input.

They do have the 3.8kw ecoflow delta pro on ebay refurb for $2175. I assume it's still not worth getting and I am better off with a full custom component setup?

Do you mind linking me to a good starting point?

I am going to look into the polyiso stuff, it is the highest R-value it seems. Unfortunately the way the walls are on, I would have to add in spacers for all the windows and doors given that the frame is only 1" thick. So it's going to be hard to go > 1".

BTW, is there any reason i should have a significant 'gap' in the walls or can I put in a full 1" insulation if the aluminum frames are just a hair wider than 1"?

I'll give you a different suggestion for insulation: spray-in closed cell foam. Take the other advice you've received, and "furr out" the walls and ceiling with 2x2's, to increase the depth by ~1.5". Then have a spray foam contractor put down 2" of closed cell foam insulation. The reason that I suggest this is that closed cell foam is an air barrier, so it'll keep humid interior air away from the metal wall of the cargo trailer. On a cold day, the interior humid air will condense water onto the metal skin of the trailer if it can reach it. Theoretically, you can use other kinds of insulation to keep the humid air away from the skin of the trailer, but the details are tricky to get right, and it's normally considered a bad idea to have more than one vapor barrier layer.

Closed cell foam will give you ~R6 per inch after it's aged, which is about the best you can do per inch of insulation. If you want more insulation, and you've got the space, furr out the wall a little more deeply, and put down 3" of closed cell instead of 2", for about an R18 insulation.

Closed cell can also be done on the floor, but it's easier to lay down rigid foam panels there.

 

[Supervstech]

The issue with using polyiso and spray foam in a trailer is flex.
Spray foam hardens and becomes brittle, it will seperate from the trailer and allow gaps and air and moisture will invade.
There is some spray foam that remains flexible, permatex? Not sure... but that might be an option. Otherwise, butyl sealant for the seams to remain air tight.
The aluminum skin might be a high quality radiant barrier if an air gap is maintained. No point using foil faced foam when it's inside an aluminum wall.