straypoet
Active member
one that i will buy when your done lol
the solar is barely enough to Temp control in south florida....and that process has driven alot of my mania with my camping needs.
mini split system would be INTENSE and it will be the most effective
LOL, I sometimes wonder about that myself.
Here is my solar AC plan of attack:
First, I will have a roughly 6x10 camper box. I used an online calculator to figure the needed BTUs to warm, or cool a 60 square foot badly insulated space:
Note, that this particular calculator estimates higher than most.
A commonly used formula is 30 BTU per square foot, so that would be 1800 BTU.... but lets go with the larger number anyway.
(reference: https://www.pickhvac.com/faq/ac-size/)
Looks like I need somewhere around 2,000BTU, so the AC needs of my small space are fairly low.
I am looking at this:
https://truckshop.lv/en/auto-air-co...nditioner-12v-sleeping-well-cube-indel-b.html
The specs are:
Compressor: SECOP single compressor BD350GH
Voltage: DC 12V
Refrigerant Gas: R134A
Refrigerant power: 3250 BTU/h (950 Watt) max*
Max consumption 12 Volt: 36 Amp/h max*
Maximum ventilating power: 6 speeds (450 m3)
External dimensions (HxWxD): 400 x 360 x 370 mm
Weight: 19,5 kg + 2,8 kg Packing
Heating function: Yes
Remote control: Yes
Battery protection system: Yes
So, since this draws 36 amps @12v, (at maximum cooling) I would need 432 watts of solar to keep it running. keep in mind that this at max draw. assuming that it ran at 2/3cycle, (based on the calculation of needing 2,000BTUs to keep it cooled) that drops to an average of 288 watts. ( I should note that a 2/3 cycle is high, the Ac should really only need to run about half the time, but lets go with the higher estimate.
If I run this at 288 watts for the full 24 hours, I need to have 6.9kwhr of total energy. (288x24=6912)
How much solar will I have available? My plan for 3x380watt panels would be an ideal (not obtainable) 1.14kw array.
Estimates for solar output is that you should only expect 0.75% of rated power, so at that rate I would theoretically be able to generate 0.855kw from this array.
Lets assume 8hrs of sun in the summer, and keep in-mind my roof is a tilting roof, if I park with the solar slanted towards the sun-arc, I think I will have better performance than a flat array. But lets just assume 8 hours @0.855kw that would give me a total of: 6.84kwhr Giving me just under what I need to keep the AC on for 24 hours straight.
Now, I know that there will be losses, there will be rain storms, there will be shade. So I really don't expect to able to generate enough to keep the AC on at all times, and I also realize that I will need power for other things, (mostly the 2 Refrigerators) and that there will be losses in charging my battery array.
But I think some of that will be offset by not being in the camper the whole day, (I don't think I could stay in a 6x10 box all day) by better insulation, by increasing the set temperature ect. ect.
In short I think that the solar array can just barely keep up with solar AC in the summer, and some solar AC is better than none.
If my result is that I can only use the AC for a few hours when the sun isn't shining, I will be happier than if I could only use it when driving.
I would take the 'guts' out of this AC unit, and mount it where the condensate can drain, and the hot air easily vent, and so that I can direct the AC to the cab when driving, and be able to direct it to the camper when camped.
(my current plan is to mount it half-above the cab, just in front of the leading edge of the solar, into the cab roof.
The other option is to buy the compressor used in the Indel cube: (or similar)
https://www.secop.com/fileadmin/use..._r134a_12vdc_101n08xx_06-2013_desd100i402.pdf
And then build my own.
Another option is to use a 120vac mini-split, but if I do this, I will have some additional inverter losses. This might be compensated by a more efficient mini-split, and might be enough efficiency to push me that direction. We will see.
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