efficiency and BTU performance of the current AC’s

[daniel_gtall]

I have a 1998 Holiday Rambler Endeavor with the 5.7 liter Cummins on a Freightleiner chassis..* We are going to be driving through southern Arizona this July (115-120 degree temps) and I am trying to figure out what to do in order to achieve cabin temps down to 80 degrees, which the 2 rooftop AC's barely do right now in 105 ambient temps.* I have serviced AC's, cleaned coils, filters, made sure no cold air is escaping or mixing with return air, etc.
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I have also painted 3-4 coats of Henry’s Solarflex on the aluminum roof (and extending to the fiberglass sides near the top of the roof) to reflect about 90% of the sun’s rays off the roof (that’s what the product says it will do).* I have also put “solar” window film on all the windows to decrease heat gain through the sides.
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During our driving through 115-degree Arizona days, I am thinking of running a 110V portable AC (that I bought at Costco but haven’t opened yet) inside the cabin (exhaust pipe to the outside via window) and run that along with the rooftop AC's but I'm not sure my 7.5 KW Onan and my power panels can handle the load.
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Is there anything else I can do to improve the efficiency and BTU performance of the current AC’s so that the RV can stay under 80 degrees inside (75 would be better) while the outdoor ambient is 115 degrees?
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Other option is to replace the original 13,500 BTU AC's with a pair of high-efficiency, low-profile 15,000 BTU AC's (that pull the same amperage) and that may help take care of my issue (albeit at a much higher cost than the $399 cost of the portable AC I bought)
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Finally, I am considering adding more solar panels on the roof, which will lower heat gain and provide more charge to the 4 house batts when we are dry camping.* Has anyone put close to 1000 watts of panels on their RV roof and if so, can you describe your system and wiring?* I have four 6-volt Interstate house batteries in my rig.

[MSHappyCampers]

Hi ! Welcome to IRV2! We're sure glad you joined the gang!

I think the 15K units would be a good long-term investment!

Good luck, happy trails, and God bless!

[Skip426]

Welcome to iRV2.

Your existing roof A/C units combined with the dash A/C' s output may do OK given the coaches movement, verses stationary , baking in the sun.

To aid your current set up , avoid travel in the afternoon , particularly driving south or west.
When in an RV park , get a site so you can face the windshield NE or due East, , to keep the windshield out of the direct sun, and have the awning out when ever possible , to keep the sun off the side of the coach.

When I leave my snowbird site in Parker , temps are sometime in the high 90's and I'll get on the road at 7 AM to cross the Mojave before noon , and get turned north ASAP on my route home.

[Gary RVRoamer]

Skip gives good advice. More btus is always helpful, but the main problem in any RV is sun-loading on the body and the un-insulated, gaping solar hole called a windshield. Do all you can to shade the rig and to insulate windshield, roof vents, etc. while parked. Extend awning(s) to reduce sun loading on the sides. Add window awnings if you can.

[Bob_C]

Insulate upper cupboards with Reflectix...I also painted the outside of the bathroom skylight with white Krylon Fusion paint....lets plenty of light in, but sure keeps the heat out...

[twinboat]

The 7.5 generator will give you 62 amps, or 31 amps per 120 volt leg.

You should be able to easily run the 3 ACs.

One leg is going to have 1 AC and the water heater on it. Plug the portable into the leg with only the other AC and low amp things.

If you can find a good deal on less effecent 15000 BTU ACs, the generator should handle them as well.

[McRod]

Originally Posted by daniel_gtall

... Has anyone put close to 1000 watts of panels on their RV roof and if so, can you describe your system and wiring?*

Pretty much the same thing you do for winterizing....insulate, insulate, insulate.

Check out the "Going Green" forum below for information on different solar options. I wouldnt invest in solar to try to run your ACs.

We added plexiglass to each fixed portion of every window, which are already dual pane insulated windows. Now they are tripl"ish" pane.

This is what 1k panels looks like, barely covered 1/2 our roof. Not setup to run ACs. Altough, I did just order a micro air easy start for our 15k unit. Should have it installed next week.

If you have the flexibilty of time, like we do, we stay out of hot areas try to move to higher, cooler ground. Even in AZ, you can travel through coconino NF and its probably 20 degrees cooler.

[beenthere]

check out the new Atwood ac's.. they draw way less amp on start and running. and also the quietest on the market///check it out...probably only need to replace the front unit..

[ThePowells]

Welcome to the forum.