Run AC with solar panel?????

[Carol H]

Originally Posted by RogerDat

My own inclination is to go with the 12v fan approach such as fantastic fan you mention. 12 volt fan is usable even in rustic without 110 from gennie. There are parts of the country where that might not be comfortable but I'm not going to be in those places often enough to make it a major concern.

adding the Fantastic Fan was the best thing I have done to my trailer. I often camp without power and the Fan does not draw a great deal of power little (I have a small solar that only gets hooked in every couple of days). Have been in areas with temps in the high 90's low 100's with only the Fantastic fan and got along just fine. Normally not in the trailer during the day so its not a big issue & in the evenings the fan does a good job of cooling the trailer down enough to sleep. Not sure if it is due to the extra foil that Scamp has up on the walls or not but the combo works.

[Byron Kinnaman]

A couple notes from the beginning.
1. Power = Power. That is number of watts remains the number of watts no matter what the voltage. If you have an A/C unit is rated at 1000 Watts at 120 Volts it will still be rated at 1000 Watts when run through an inverter with the inverter running with 12 volts in. The 12 volt system makes the math pretty easy. When looking at a 120 volt item you want run using 12volts a multiply the rated current time 10. Example above 8.3 amps at 120 volts = 83 amps at 12 volts. (Note to Jim, drop the hours that's, in the case of trailers, for batteries).

2. Except in extreme cases I've found a "Constant Breeze" made by Fantastic Fan, works great. Even when I got stuck in lows of 75° the air moving across us kept us cool enough to sleep.

[RogerDat]

Originally Posted by Byron Kinnaman

.....Example above 8.3 amps at 120 volts = 83 amps at 12 volts. (Note to Jim, drop the hours that's, in the case of trailers, for batteries).......

Good info on that conversion.

Considering an 85 watt solar panel might be 5 amps and... well that won't work. Always going to be running off of battery, drawing more than solar can provide.

Real question then is how long will it take to drain the amp hours off the batteries at the AC amp draw with the solar amperage input.

Just a ballpark but... one 85 watt panel at 5 amp might be 30 ah a day (using charge at 100% for 4 hrs, 50% for 4 hrs) so three panels would "add" enough to run AC for approx one hour. Running into negative for daily power after that. Dual 200 ah batteries give you approx another 2 hrs of power for AC before batteries hit 50% charge. But it would take 2 days of no AC to replace that battery power from solar.

So if you had good sun and about 48" x 65" of solar panels.... Sounds like the fan is the waaay better option. There are parts of the country where not having AC would probably be a pretty poor option. But need shore power or gennie to run it. Or go during cooler season. Only reason to go to Fla in summer is to time how long it takes CD collection to melt without AC.

[Victor Benz]

I am no solar expert, but I am willing to learn. I have discovered that most RV solar experts aren't. that led me to this blog, which has some interesting perspectives, but well worth the read if you are planning an off-the-grid existence.

HandyBob's Blog

Vic

[Frederick L. Simson]

Stay Cool with TurboKOOL - Advanced RV Evaporative Air (Swamp) Coolers

Originally Posted by P. Raz

... hence the name evaporative cooler and as such only work well in low humidity locations. The name "swamp cooler" seems erroneous. Perhaps someone who has some experience with one can give some insight.

In the United States, the use of the term swamp cooler may be due to the odor of algae produced by early units. - from Wikipedia

In the 1960's my grandparents cooled just the living room of their farmhouse west of Oklahoma City with a side-draft "swamp cooler" mounted at a window. In the 1970' and 1980's I lived in a 10' x 50' mobilehome with a down-draft cooler on the roof. When I first bought my Fiber Stream it had an old RV evaporative cooler that I tried to revive, and gave up on before I replaced it with a Fantastic-fan.

I can attest to the "odor of algae" produced by a stationary unit. The trade-off is while (110 volt ac) electric power usage is low, water consumption is high, and it needs to be constantly replenished during use, especially when the humidity is below 20%. When the humidity was above 80% I just used the fan, as on "cool" it caused condensation to form on the wall paneling without improving the temperature. I was constantly on the roof maintaining the thing, mostly adjusting the float valve, and cleaning calcium from the spray tubes... With a roof mount you have to remember to switch to fan only 1/2 hour before you turn it off completely, or the water draining from the excelsior pads will overflow the reservoir. You also have to keep just 1 window cracked open slightly (preferably at the opposite end of the trailer from the cooler's location) to exhaust air. I gave up on the old RV cooler because I could not stop the leaking into the trailer.

[Raz]

Thanks Frederick.