an air conditioner running on solar without batteries

[pianotuna]

Hi all,

Interesting idea!

http://www.hotspotenergy.com/solar-air-conditioner/

It can be used for heating, too!

[Chum_lee]

drsteve wrote:

pianotuna wrote:
Hi 2oldman,

It is rated at 12,000 btus.

Footnote from the spec sheet:

*BTU capacity may be reduced when solar power is limited. An AC backup connection is recommended for full & uninterrupted operation.

Yep. That's the FIRST thing that I noticed in the specs. So you have an AC that's UP TO 12,000 BTU's. The devil is ALWAYS in the details, not the large print! No news/free lunch here.

Chum lee

[time2roll]

deleted

[drsteve]

pianotuna wrote:
Hi 2oldman,

It is rated at 12,000 btus.

Footnote from the spec sheet:

*BTU capacity may be reduced when solar power is limited. An AC backup connection is recommended for full & uninterrupted operation.

[Ralph_Cramden]

MEXICOWANDERER wrote:
theoldwizard1

Under the heading of Gyro Gearloose high quackery check out the number of "revolutionary deigns" worthy of a Jack Nicolson, Nurse Ratchett cast. National Enquirer first page coverage...

A pure solar 1500 sq ft. home would cost me 120,000 - 150,000 dollars because of tropical weather. Three thousand watts of AC going 24 hours a day eats 57.6 kWh of power. Then there is another 10 kWh of dehumidifier. Refrigerators freezers yadda dadda. How many 24 volt panels does it take do replenish 57.6 kWh in an EIGHT HOUR DAY? Then add in the other stuff. A lot of panels, and you forgot to include the popcorn machine which could pull at least 1200 watts LOL



There's nothing wrong in dreaming until you start believing it. One thousand cycles every three years means one set of batteries every nine years. Wanna put Rolls & Surrette on speed dial?

Gyro Gearloose high quackery worthy of a Jack Nicolson, Nurse Ratchett cast. ROFLMAO, that's funny!

[valhalla360]

pianotuna wrote:
Hi 2oldman,

It is rated at 12,000 btus.

You are confusing the theoretical maximum output with the realistic output.

You might be able to run max output for a couple hours mid-day if it's a clear sunny day.

Morning/Late afternoon...not so much.
Night time...not at all.

There is a reason, no one recommends solar systems without a sink to absorb excess power and to boost when there is a deficit. That sink could be batteries or the grid (though the grid rarely benefits since peak demand is usually early evening).

[MEXICOWANDERER]

theoldwizard1

Under the heading of Gyro Gearloose high quackery check out the number of "revolutionary deigns" worthy of a Jack Nicolson, Nurse Ratchett cast. National Enquirer first page coverage...

A pure solar 1500 sq ft. home would cost me 120,000 - 150,000 dollars because of tropical weather. Three thousand watts of AC going 24 hours a day eats 57.6 kWh of power. Then there is another 10 kWh of dehumidifier. Refrigerators freezers yadda dadda. How many 24 volt panels does it take do replenish 57.6 kWh in an EIGHT HOUR DAY? Then add in the other stuff.

There's nothing wrong in dreaming until you start believing it. One thousand cycles every three years means one set of batteries every nine years. Wanna put Rolls & Surrette on speed dial?

[theoldwizard1]

Check out the YouTube channel Engineer775. He has installed a few of these.

You will need a lot of panels (900W minimum).

No batteries is ridiculous. One cloud and your AC shuts off. How many batteries is debatable.

[MEXICOWANDERER]

Where I live, daytime is for swimming and night time is for sleeping.

Lunar panels?

I did workup on this (including batteries for 24 hour AC, and the total was frightening. More than a hundred grand. And that was with lead acid batteries and a small split A/C.

[KD4UPL]

This unit isn't intended for RVs but for stationary homes. It's very similar to any other mini-split heat pump these days. They are all remarkable efficient.
I recently completed a solar/battery/generator system on an off grid house. He had 2 mini-split systems. I asked the HVAC technician to run them both simultaneously at maximum load so I could see how much power they would draw. I was truly surprised how low it was. I think both units together at maximum cooling were using around 1,000 watts. Both units on maximum heating I think were using around 2,000 watts. There was no starting surge as the compressors start at a slow speed and ramp up to whatever speed they deem necessary for the heating or cooling load.
Putting a unit like this on an RV would be a huge step up in efficiency from the traditional roof mounted AC unit. It would also be much quieter. However, I don't see it happening for the majority of RVs due to the size of the equipment and the cost.
As for the solar panels, they're a nice gimmick I guess. They would, when it's really sunny, reduce your power consumption. However, even the add posted states that the system is not designed for off grid use. The problem with the solar panels being hooked to the HVAC equipment is that they don't do you any good when it's not operating. So, during the typically mild spring and fall when sunshine is often plentiful the panels might spend lots of time doing nothing. If they were hooked to a traditional grid-tied system on a house they would always be producing and lowering your electric bill whenever light was available.

[Gulfcoast]

What happens if you need A/C at night, early mornings, late afternoons, when it's cloudy or raining? I'll pass for now...

[SidecarFlip]

Besides it's a mini-split and not really suited for RV application.

[2oldman]

Interesting specs.. minimum DC voltage is 100, so the panels will be in series, as they say. Maybe it's there in the specs, but I don't know how they deal with startup surge.

What I mean by free lunch is that they're trying to sell the idea that, with a few panels, you can have 'free' air conditioning. Maybe, if conditions are just right, for a short time. Now, if you had a bank of batteries with high enough voltage, yeah, that could work, but they don't want to talk about that.

It's like these ads for a 'solar battery.' No, don't think that's right.

[time2roll]

I like that it can run on less than full 960 watts. Or supplement from utility power. For those with monthly electric bill this will reduce power when the sun is out for both heating and cooling. No net metering agreement needed. For those running a generator it will reduce fuel consumption significantly. I assume start surge is minimal so maybe a Honda 1000 would work with the solar. Endless good possibilities in many situations.

We all know it would take 2000+ watts of solar to really run the A/C and this unit lets you operate right at the fringe.

[pianotuna]

20ldman,

1795 usd is hardly a free lunch--and then 3 ~400 watt panels are required. Then there is the installation cost.

If I were still full time, I'd be looking at it carefully.

The spec sheet says a maximum of 1046 watts is required. I wonder how they get around the start up surge?