DIY Composite Flatbed Camper Build

[Terra Ops]

1,400W of it...

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Ah, I guess I think of it more in terms of "needing" a large enough battery bank. The solar is not really needed to run the AC as I have run my 12 volt unit all night. The lithium
batteries is what makes this possible. Faster charge and nearly twice the discharge of lead batteries. While the solar is necessary to charge during the day, the batteries can also be charged through a running vehicle or shore power.
The informative part of the videos is the power consumption/efficiency of the entire system, including the rig itself.

 

[shirk]

More food for thought. Plenty of camper units struggle with condensation, the common cue being dry heat with lots of air exchange. A refrigerator dehumidifier will pull moisture out of the air and provide heat. Damp air feels cooler so drier air would help. Lots of the small portable units are 4 in 1, heat, cool, dehumidifier, and fan. The dehumidifier cycle adds heat the space. Might be able to cut down on the amount of air exchange needed and thus less heat required.

 

[rruff]

Ah, I guess I think of it more in terms of "needing" a large enough battery bank.

I think that's even more "insane"... 11.5 KW-hr battery bank. It's a very big solar system for a small camper.


And in the video you linked he's using ~530W average for the AC when it's 88F outside.

 

[Terra Ops]

More food for thought. Plenty of camper units struggle with condensation, the common cue being dry heat with lots of air exchange. A refrigerator dehumidifier will pull moisture out of the air and provide heat. Damp air feels cooler so drier air would help. Lots of the small portable units are 4 in 1, heat, cool, dehumidifier, and fan. The dehumidifier cycle adds heat the space. Might be able to cut down on the amount of air exchange needed and thus less heat required.

I've had other campers where condensation was an issue, but not with this one due to the foam panels and non thermal bridging. However, I do realize the benefits of the mini split system. I will definitely consider this in the next build. You mentioned going all electric,... that too is my goal. I've found the you tuber "gone boondocking" very interesting.

 

[rruff]

How will your next camper differ from the current one in size, construction, etc?

 

[Terra Ops]

I think that's even more "insane"... 11.5 KW-hr battery bank. It's a very big solar system for a small camper.


And in the video you linked he's using ~530W average for the AC when it's 88F outside.

I suppose you do given your past thoughts and opinions. That's cool. Your tag name "rruff" says it all!

 

[rruff]

Your tag name "rruff" says it all!

Yep... mine is a mobile dog house... nothing fancy.

 

[shirk]

I will definitely consider this in the next build. You mentioned going all electric,... that too is my goal. I've found the you tuber "gone boondocking" very interesting.

I have been following this build on Casa Trotter in France.

Adieu Sprinter, bonjour Ford Ranger, Partie 7 - Casa Trotter

It got me thinking of ways to go full electric on a similar sized build.

Our local gov recently put out a program on some rebates for people moving to heat pumps and the combination of two has driven me down the rabbit hole of research on heat pumps.

Here is another video showing what a modern dc based heat pump pulls for power on heat.


A larger system on cooling.


I will have a look at the "gone boondocking" youtube.

 

[skirunman]

If I was to hack an inexpensive AC for a small camper I think the Midea U Inverter 8K BTU Window Unit would be a good start. Modern compressor, only $340, can fairly easily separate as it is basically a mini-split. Obviously does not solve the heating issue. Here is a video of a guy separating one. Otherwise I'd use a Pioneer 22 Seer 9k Mini-split to get both heat and cooling for $870. Still have inverter loss for both these solutions as they are 120V AC.

 

[skirunman]

Here is another video showing what a modern dc based heat pump pulls for power on heat.

A larger system on cooling.

Don't both the marine AC/heat pump units you linked to require sea water for the condenser so would not really work in a camper van?

 

[shirk]

Don't both the marine AC/heat pump units you linked to require sea water for the condenser so would not really work in a camper van?

Correct these use sea water. The main power draw on these is the compressor so the video's show what the power consumption would look like for a unit with a modern dc compressor.

Marbu has a video of one of their units running a glycol mix through a small car rad to show how it could work in a van instead of using sea water. Power draw should be the same as they use a small pump for the sea water and I assume that would be the same on the closed loop system.

 

[skirunman]

Correct these use sea water. The main power draw on these is the compressor so the video's show what the power consumption would look like for a unit with a modern dc compressor.

Marbu has a video of one of their units running a glycol mix through a small car rad to show how it could work in a van instead of using sea water. Power draw should be the same as they use a small pump for the sea water and I assume that would be the same on the closed loop system.

So I guess one could hook it up to an auto type condenser/fan like this one for approximately $700? These can be undermounted, which could be nice. Total cost then about $6k before install for the Mabru unit.

 

[shirk]

So I guess one could hook it up to an auto type condenser/fan like this one for approximately $700? These can be undermounted, which could be nice. Total cost then about $6k before install for the Mabru unit.

No you don't need a condenser as the refrigerant is in it's own closed loop. There is a counter flow heat exchanger tucked in between the compressor and the evaporator on the Mabru units and the sea water runs through this. You just need simple water radiator.

 

[Terra Ops]

You may want to check this out. Vertical Wall Mount Evaporator/Condenser 12V & 24V - KANADA II - DC POWER SOLUTIONS (dcpowersales.com)
I bought my roof top unit from them. I think they also sell a split system. Don't see a combination of heat and air though. One thing I love about the residential
split systems is how quiet they are. My roof unit is loud.

 

[Le-Doctor]

Love your build! I considered something similar, but ended up going with hand layup on 20 psi Foamular, so I could do curved surfaces. I used the cheap foam because I couldn't find anyone willing to get the 60 psi foam locally, and shipping would have doubled the cost.

What are the specs for the skins you are using? Thickness, weight? FG, polyester resin with gelcoat?

How did that work out for you? I am considering a similar build for a demountable camper like this one - but was considering layering the grp with a slow curing epoxy so i might finish it all in one go (cannot find a supplier of finished skins in my area)

any recommendations? How did the cheaper foam attest to time?