AC question in regards to inverter

[Choc Lesnar]

I'm consider purchasing a small air conditioner for the bus, it runs at 5400 BTUs. I currently have 8 solar panels at 260 watts each (a total of 2,080 watts) what size inverter do you think I should purchase? I haven't bought the batteries yet, I just wanted an idea. I was thinking if getting a 3000 watt inverter. Any ideas or suggestions would be greatly appreciated. Thank you!

[john61ct]

From a quality company like Magnum or Victron, whose ratings are more reality-based than cheap Chinese gear

1000W might be enough

3000W might be OK from the latter.

A soft-start unit will help, the continuous draw is a small fraction of the peak load from the compressor spinning up.

True sine wave is also important.

With such a small solar rig, relative to the aircon load if the ambient is hot

even if your "cool space" is a small **very** well/tightly insulated section

you will be able to run the aircon in good insolation conditions (no parking in the shade allowed!)

directly off the solar incoming

**but** you won't be able to also fully recharge your battery bank at the same time,

if you plan to run the aircon between say 4pm and 10am (depending on weather and latitude) for more than an hour or two.

All this assumes no other significant loads, solar pretty much dedicated to that one small aircon unit.

A small quiet inverter genset will help a lot, and a LFP bank is IMO a must.

Bad news is 2000+Ah would be about the right bank size (conservtively) if you want to significantly reduce the genset runtime.

In summary, running aircon off grid from "mostly solar" is pretty impractical.

Run it from the genset, and then strive to redce its runtime with the solar.

Best off all, relocate to higher altitudes and latitudes, "follow the 60's" when the weather gets uncomfortably hot.

[dzl_]

Originally Posted by Choc Lesnar

I'm consider purchasing a small air conditioner for the bus, it runs at 5400 BTUs. I currently have 8 solar panels at 260 watts each (a total of 2,080 watts) what size inverter do you think I should purchase? I haven't bought the batteries yet, I just wanted an idea. I was thinking if getting a 3000 watt inverter. Any ideas or suggestions would be greatly appreciated. Thank you!

A couple questions that will help define an answer:


1. Is the AC a minisplit (inverter AC)?



2. How efficient (SEER or EER)?


3. Will you have other large AC loads that might occasionally run simultaneously?




I would also second John's point that there is a substantial difference between a cheap Amazon/Aliexpress HF inverter and a robust high quality LF inverter from a reputable brand.

[bus-bro]

What voltage is your battery bank?

I would be curious to see pictures of inverter input cabling for a 12 volt 3000 watt inverter that runs anywhere close to that power output. I say this because I recently wired up a 2800 watt inverter to a 12 volt bank. Manufacturer's recommendation is 4/0 cable at 5 foot cable length. What I am trying to say is you got a lot of copper in a 12 volt system. Though when you up the battery bank voltage you up the hazard of a slip-shod installation.

That being said, I might consider running the AC on a dedicated 12 volt sin-wave inverter.