Hi,I'm Dachia.. in the market for a Scamp or Burro, I think

[Bob Miller]

Not to be sour grapes here but.....


Those are all interesting ideas, but have you done what's suggested and can you report actual results???
What's being suggested sounds not only like a lot of theory, but a lot of $$$ as well.


BTW: There aren't many FGRV's with roofs physically big and strong enough to support as much solar power as it would take to run even the smallest a/c and running an unattended generator is a no-no anyway.

[David Tilston]

Ummm. Well Bob Since 100 w of solar, on a flexible panel weighs 4 lbs.
100W Watt 12V Volt Semi Flexible Bendable Efficiency PV Cell Mono Solar Panel | eBay
"While this solar panel packs 100W of power, it only weighs a mere 4lbs"

500W would only weigh 20 lbs. Given a large enough inverter and battery bank to provide the start-up current, this could possibly run a 5000 btu air conditioner. Six panels are probably required though.

[Bob Miller]

The example given was for panels that look like they will weigh a lot more than 4 lbs. each and, at 22"x47" 4 will be a crowd on a small FGRV's roof.


In checking specs for 5000 BTU room a/c's it looks like an average current draw is about 4.5 to 5 amps, that's about 550 to 600 watts meaning, in reality that even 6 panels would not be able to keep up unless you could somehow assure 100% output.


My point was that these are ideas that might work out on paper but, unless someone actually proves the example, it's still just theory and can only add false hope to the needs of the o.p. In some past posts they often read like someone wishing that their idea would get tried at someone else's expense.


And in the op's example, suggesting adding about $1000+ in extra expenses for something that "might" work, without an existing example, just isn't fair.....


This topic is oft visited and, despite all of the knowledge and hype, I've yet to see anyone build such as system on an FGRV. These are vacation trailers, not space shuttles, simplicity and cost are usually paramount.

[Dachia]

Thanks Bob and David.... I appreciate your input and advice.

[David Tilston]

Originally Posted by Bob Miller

The example given was for panels that look like they will weigh a lot more than 4 lbs. each and, at 22"x47" 4 will be a crowd on a small FGRV's roof.

Hmmm... not sure where you are getting your dimensions. From the linked page:
Dimensions: 41.3 X 21.3 X 0.12 In

I realize we are only talking a 5.7 x 0.7 difference.

Four on the roof would be a crowed, but one on a rock guard, on each end, and two on the roof is not out of line.

Assuming that the numbers are accurate, (it is likely that they are optimistic) these solar cells have an energy density of 0.114 W / square inch. Lets assume that the roof of a trailer is 72" x 120". This is room for 982 Watts. Enough for a 5000 BTU air conditioner, with some left over. Using the established 4 lbs for 100 watts, that would be about 40 lbs spread over the whole roof. Not unreasonable.

The cost would be high. The solar panels would have to be custom made. Several solar controllers would be required. A large battery bank, and large inverter would also be necessary. Hey, maybe even a tongue jack, with a motorized wheel, to keep the trailer pointing the right way. But, it is possible.

[papa-t]

If you have one with a fantastic fan where you can set the air to be drawn out or in. In the out position it keeps the camper cooler by drawing the heat out.

[Donna D.]

I've been following Chris and Cherie of Technomadia for a number of years. If they say it's next to impossible to get enough solar to run an A/C, I'm very inclined to believe them. Read the entire story here: The (Almost) Fantasy of Solar-Powered RV Air Conditioning | Technomadia

[Dachia]

Have heard/read about that Fantastic Fan... on the list. ;-)

[Bbbabs]

Hi!

I came across this link for keeping cool in your RV at Burning Man. I especially liked the tip about evaporative coolers! Hope it helps!
Keeping Cool In Extreme Heat - Ideas From Burning Man

Barbara

[Bob Miller]

Evaporative coolers only work when the relative humidity is 50% or a lot lower. Easy-Peasy at Burning Man on the Playa (Nevada high desert), but not so easy to find in the middle of the country.


They have been offered for vehicles since the 30's and for RV's since at least the early 60's, and still don't really work except under very limited conditions. Basically, it's not something you can count on from day to day.

[David B.]

Originally Posted by Dachia

Have heard/read about that Fantastic Fan... on the list. ;-)

I have had both the Fantastic Fan and the MaxxAir fan, and prefer the MaxxAir fan, as it has more fan speed selections, and can be left open in the rain.
Dave & Paula

[David Tilston]

Originally Posted by Donna D.

I've been following Chris and Cherie of Technomadia for a number of years. If they say it's next to impossible to get enough solar to run an A/C, I'm very inclined to believe them. Read the entire story here: The (Almost) Fantasy of Solar-Powered RV Air Conditioning | Technomadia

From the linked article:
100% Solar RV AC Can Be Done – If You Design For It

If I read it correctly, it seems to say that for a small RV, like an egg, and remote solar panels, (so you can keep your RV in the shade), using an efficient home style A/C, it should work.

[Jon in AZ]

It can be an expensive journey from "possible" to "practical"!

[Dachia]

David B, thanks for the fan suggestion. I'm still following the AC discussion, thanks everybody.