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Words of Wisdom: “It's not a lost cause.. we just seem to be at that frustrating cusp where it's technically possible with current technology, just not easy or cheap.” – thatswhatsup1)

Running AC on [an inverter] is rich man's game – HaldorEE2)

I want to run A/C off solar

Understood, we all would like to do that. We wish it were simple and inexpensive enough to be common. It's not common. Some folks do have A/C but the great majority of them are getting power from a generator or shore power.

Unfortunately, if you are reading this you probably haven't done the math. Prepare for some unpleasant news, because at this point you may not be familiar with:

  • how much power it takes to run the A/C unit continuously
  • how much power it takes to start the A/C unit (usually much more than running it)
  • how much solar panels are derated in actual use. If it's hot enough to run A/C it's hot enough that you are already losing 25% of your solar panels' rated output due to voltage depression. That is before wiring and charge controller losses.
  • how much space those panels will require
  • how much money those panels will cost to acquire
  • how much money big solar charge controllers cost

And that's just considering running the unit in optimum solar conditions in the daytime. Running A/C at night requires a magnitude increase in battery bank. That is either $$$, heavy, or both.

There is a reason people snowbird (follow good weather) and use roof vents to control humidity and temperature.

One exception to this dilemma is available if you live in the desert; swamp coolers do a good job of cooling in areas of low humidity. They use very little electricity but a great deal of water.

But some people are doing it!

That's right. People also make 200mph Pintos and 20ft tall bicycles.

There are people with an in-depth understanding of the issues, and the money and space to make it happen. It does not stand to reason that the average person with average resources and commitment will make the trip from idea to implementation.

If you would like to learn more about how it's been done before, start with this post by trebor then check out posts by people who have done it:

Also see

but RVs are doing it

RVs and travel trailers typically power their single A/C off 30A (3,600W) shore power, and sometimes can't run that and a MW at the same time depending on other loads. Dual A/C typically runs off 50A (12,000W) shore power.

When away from shore power they run generator power into the shore power port.

hvac/solar_ac.txt · Last modified: 2023/03/02 12:03 by frater_secessus