Powering a mini split

[Brasher801]

It all depends on average (or steady-state) draw by the mini-split.
PV has to produce all the power consumed. Batteries are mostly to provide power consumed at night.
Hopefully, heat load is less at night and much less power is consumed 8:00 PM to 8:00 AM.

I think I saw spec for one mini-split and power consumption varied 3:1 (900W down to 300W), but BTU varied 8 or 9:1.
That would mean a fraction the efficiency at lower power, and you'd be better off cycling it on and off. Might consume 1/3 as much energy that way.

Yeah I think that’s right. From 900-300. And I would think it would not run near as much at night. I guess the real test will come when I try it! Lol

 

[McCarthy]

Use this calculator, it will tell you how many panels and what battery size you will need.

RV and Camper Van Solar Calculator

Campervan solar calculator to help you decide how many solar panels, batteries, and what size inverter to use for your camping solar system. DIY wiring diagrams for solar panel systems of all sizes.

www.parkedinparadise.com

 

[NMNeil]

I bought the 9000 BTU Pioneer Inverter type. Sheet says 960 Watts Max.

And that would be for the heat pump.

 

[chrisski]

And that would be for the heat pump.

I still think by now, someone has some data that can be used to really plan how much energy is used such as, "During the Maine summer day of 85° I used XXX watts per hour, to maintain a temp of 76°" or in my case, "On a hot summer night in Arizona of 91°, I used XXX watts per hour to maintain a temp of 80°." A couple of examples about the extremes in your area, in my case one for day and one for night, would narrow this down.

We can all read the start up amps, and figure out watt hours from there by guessing, but there has got to be a better way than, "You've got to build it to find out." After all, this is not Congress. I can't afford to buy into the idea of Air Conditioning without knowing what its going to cost, because unlike the federal government, I have to pay my bills.

 

[McCarthy]

I still think by now, someone has some data that can be used to really plan how much energy is used such as, "During the Maine summer day of 85° I used XXX watts per hour, to maintain a temp of 76°" or in my case, "On a hot summer night in Arizona of 91°, I used XXX watts per hour to maintain a temp of 80°." A couple of examples about the extremes in your area, in my case one for day and one for night, would narrow this down.

Will be highly inaccurate because of these issues:

- tolerances of measuring tools
- different vehicles being used
- vastly different insulation being used
- huge difference between vehicle being in sunlight, partial sunlight or shade
- humidity
- elevation (pressure)

In general, I don't think that 500 or 1,000 watts will cool down on a summer day a larger van let alone RV. Most car AC units can pump out up to 40,000 BTU and even they run into limitations on hot days. You do the math what 2,000 or 4,000 BTU unit can do.

 

[McCarthy]

PS: In a modern automobile, the A/C system will use around 4 horsepower. That's 3,000 watts. For a small car.

 

[Freep]

How tall is your toy hauler? I ask this because you could set up a rack over the roof of your hauler and completely cover it with solar. Not only would you maximize your energy harvest you would also shade your roof, making it that much easier to cool.

 

[MisterSandals]

I still think by now, someone has some data that can be used to really plan how much energy is used such as, "During the Maine summer day of 85° I used XXX watts per hour, to maintain a temp of 76°" or in my case,

Someone with one on these Pioneer 9000 BTU Inverter Split-mini’s?

 

[RogerD]

Until you run the AC for 24 hours under different outside temp conditions. You will never know for sure how much power it's going to use. How well your rig is insulated will be key as well. I think you have to at least be close. Also depending on temps at night, maybe you can get away with some decent fans and save power. Can't hurt to have a generator as a backup.

 

[corporate.joe]

Most car AC units can pump out up to 40,000 BTU and even they run into limitations on hot days.

Yeah, cars are like rolling greenhouses.

 

[JoeHam]

One data point here.

At the 3:33 mark, on a portable mini split :

 

[CaseyB]

One data point here.

At the 3:33 mark, on a portable mini split :

The problem with starting it with his inverter leads me to believe it’s not a inverter compressor. Inverter AC’s don’t have the start up current “surge” of a on/off compressor.

 

[McCarthy]

The problem with starting it with his inverter leads me to believe it’s not a inverter compressor. Inverter AC’s don’t have the start up current “surge” of a on/off compressor.

A proper cap should help either way.

 

[CaseyB]

A proper cap should help either way.

True, but that won’t make it as efficient as a inverter supply. The point I didn’t make well enough is that the AC in the video isn’t comparable to the more efficient offerings out there.

 

[CaseyB]

True, but that won’t make it as efficient as a inverter supply. The point I didn’t make well enough is that the AC in the video isn’t comparable to the more efficient offerings out there

I meant Inverter compressor not inverter supply.

 

[corporate.joe]

I've looked into that forrestair unit before. Saw that same video. The wattage of that unit is horrible for what it is. The roof top unit from the early 90's that I have pulls 1,200 watts when the compressor is on and it's 15,500 BTU.

 

[Brasher801]

How tall is your toy hauler? I ask this because you could set up a rack over the roof of your hauler and completely cover it with solar. Not only would you maximize your energy harvest you would also shade your roof, making it that much easier to cool.

I have 8’ x 24’ I can use

 

[iamrich]

6 x 1 of the 72 cell panels or 2 x 4 of the 60 cell panels assuming you don't have any vents or other obstructions. Even with 250w panels, that's 2kw. I think I would go for x6 350w panels. That should leave roof on the roof even if you have a standard vent. That would get you 2100w max. probably under $1000. Run them 2S3P (~80v at ~27a)

Any idea what controller and inverter you plan on using?

 

[Brasher801]

6 x 1 of the 72 cell panels or 2 x 4 of the 60 cell panels assuming you don't have any vents or other obstructions. Even with 250w panels, that's 2kw. I think I would go for x6 350w panels. That should leave roof on the roof even if you have a standard vent. That would get you 2100w max. probably under $1000. Run them 2S3P (~80v at ~27a)

Any idea what controller and inverter you plan on using?

I literally have no idea what inverter to use. But I do like the 6x350w style panels! And all I have on the roof is a standard vent. Nothing else.

 

[mrdavvv]

If money its not much of a problem, consider checking on higher SEER units.

For example, a 12K BTU inverter with 16 Seer would take around .75Kwh, for 8 hours, that's almost 6Kwh, so in my case 3 or 4 400W panels could make it.

There is 30 Seer inverters, so 3.2Kwh for the same 8 hours, almost half of energy and panels!, but around 500 - 800USD extra or more depending of the size.

Disclaimer: Maybe im wrong since i havent done this numbers in a while.