YES: RV Solar/ Li/ and AC running full time

[RogerD]

@aangel

Here is a video worth watching.

 

[RogerD]

If I go by EER, I'm using more energy than I produce with the assumptions I've made (7748 W•hr > 6206 W•hr). Since the OP has his working fine, that indicates to me I may be too conservative in my assumptions.

Your power usage isn't going to be static with a mini-split. Once your set temp is reached it should use much less. However, the size of your rig, how well it's insulated, and the outside temp will all affect it. EER if I recall correctly is based on 95F / 50% humidity test conditions.

 

[aangel]

Your conclusions look good with the exception of the 9000btuh units heating demand.
If you look at the specks on the above 9000btuh senville unit it states a 200 watt increase in demand while heating, something to note for 24/7 usage calculations. the 12,000btuh unit doesn't. This is very interesting to me, is it really that much more efficient?

Thanks for the feedback. Good to hear I'm on track.

I'm not too concerned with heating, though I'll add those to the spreadsheet on the next revision. I have a Webasto heater already installed and it gets its fuel directly from the main 55 gal gasoline fuel tank.

 

[aangel]

Your power usage isn't going to be static with a mini-split. Once your set temp is reached it should use much less. However, the size of your rig, how well it's insulated, and the outside temp will all affect it. EER if I recall correctly is based on 95F / 50% humidity test conditions.

Thanks for the feedback.

I've seen that video and it's very good. They, too, detest the sound of these loud a/c units! It's driving me insane.

 

[aangel]

Just discovered a hybrid mini-split unit. It runs on DC and AC:

"This is the 5th generation of our ACDC12x solar air conditioner series with a new key feature we've had so many requests for - our new "C" model ACDC12C solar air conditioning technology requires no grid connection. Like previous versions, it also needs no batteries, no inverter, no charge controller - just plug in the solar panels and start saving up to 100% on daytime cooling or heating costs. A grid connection can be added to automatically allow operation at night, as well as to provide higher daytime capacity & uninterrupted operation during cloudy or low sunlight conditions. See ACDC12C Spec Sheet

During the day the ACDC12C can run exclusively on solar power with no AC power or grid connection when solar is strong enough. The maximum speed/capacity will be based on the level of available solar power available. If also connected to AC power source, the unit can run at full speed whenever needed, and will add in just enough AC power, if/as needed, while still primarily using available solar DC power."

DC Solar Air Conditioner Heat Pump | Solar Air Conditioning | Solar Heating | Manufacturers

 

[Lt.Dan]

That has been posted a couple of times. I always blew it off because I couldn't find a price and assumed it was very high.

They also make a 48v DC only model that looks very promising. Any idea on price?

 

[aangel]

Sorry, I must have missed that.

$1895 for the 12k BTU model.

 

[curiouscarbon]

i visited someone recently who had a

whynter elite 12000 BTU dual hose digital portable air conditioner

in a very small apartment. they used it to cool off the apartment while we were in it. it worked really well, had two hoses that went to the window. it rejects condensation by evaporating it using the condenser coil heat

right now i’m using a midea U 8000 BTU device, and it’s ok but the dual hose whynter one seems even easier to integrate

anyone have any experience with dual hose units?

single hose is junk of course, but dual units are legitimate design to me

 

[AHUSAIN]

Can anybody tell me if a 9,000 BTU mini-split would be enough to cool a 35 ft motorhome in the heat of the desert? I've already got it half installed and I have to hit the road in 3 weeks. After watching this video and reading this discussion, I'm starting to doubt my choice. Is it necessary for me to go up to 12,000 BTU?

 

[K8MEJ]

Can anybody tell me if a 9,000 BTU mini-split would be enough to cool a 35 ft motorhome in the heat of the desert? I've already got it half installed and I have to hit the road in 3 weeks. After watching this video and reading this discussion, I'm starting to doubt my choice. Is it necessary for me to go up to 12,000 BTU?

In my experience, probably not. I have a brand new LG 12,000 BTU 115v mini-split installed in the front bedroom of my 28 foot travel trailer. Even if I leave the bedroom door wide open, I have to use a Vornado fan to push cold air to the rear of the camper. I only have single pane windows so that hurts quite a bit. It was 90 degrees with 70% humidity this past weekend and it barely kept the rig at 74 degrees. I have a single 15K BTU roof-top unit that I have to kick on, too, to do the initial cool so that it doesn't take 8 hours to cool the camper down. This was the biggest 115v unit I could find anywhere. If I could have installed it near the middle of the camper it might be more effective.

You're going to want to look into Magne Curtains to help block the heat, if you don't already have something in place.

If you have 240v in your trailer look at getting an 18k BTU unit. Maybe my situation is an anomaly. Hopefully others can discuss a better scenario.

 

[Partimewages]

Can anybody tell me if a 9,000 BTU mini-split would be enough to cool a 35 ft motorhome in the heat of the desert? I've already got it half installed and I have to hit the road in 3 weeks. After watching this video and reading this discussion, I'm starting to doubt my choice. Is it necessary for me to go up to 12,000 BTU?

Depending on your layout even the 12000 might not be enough. We have a 38' 5th wheel and I am figuring 18000 to 24000 to do it. I do HVAC and Electrical for a living.

 

[Groscout]

Can anybody tell me if a 9,000 BTU mini-split would be enough to cool a 35 ft motorhome in the heat of the desert? I've already got it half installed and I have to hit the road in 3 weeks. After watching this video and reading this discussion, I'm starting to doubt my choice. Is it necessary for me to go up to 12,000 BTU?

Good after noon, I'm currently running a 12,000 btu mini split in a 35' bus. It is 103F outside with humidity of 16% and about 77F inside. I would not expect this to work at all w/o window coverings and a fan, especially if i were to try to cool it down mid day in full sun. In other words of you like it at 68F and fast(er) do two 9000s one in front one in back. I still have to make a few insulation improvements and fill some holes so my extreme temp performance should go up

 

[AHUSAIN]

Good after noon, I'm currently running a 12,000 btu mini split in a 35' bus. It is 103F outside with humidity of 16% and about 77F inside. I would not expect this to work at all w/o window coverings and a fan, especially if i were to try to cool it down mid day in full sun. In other words of you like it at 68F and fast(er) do two 9000s one in front one in back. I still have to make a few insulation improvements and fill some holes so my extreme temp performance should go up

Thanks a lot. I really appreciate that information.

 

[AHUSAIN]

Depending on your layout even the 12000 might not be enough. We have a 38' 5th wheel and I am figuring 18000 to 24000 to do it. I do HVAC and Electrical for a living.

Thank you. I guess I misjudged big time. I have to scramble for a solution now.

 

[AHUSAIN]

In my experience, probably not. I have a brand new LG 12,000 BTU 115v mini-split installed in the front bedroom of my 28 foot travel trailer. Even if I leave the bedroom door wide open, I have to use a Vornado fan to push cold air to the rear of the camper. I only have single pane windows so that hurts quite a bit. It was 90 degrees with 70% humidity this past weekend and it barely kept the rig at 74 degrees. I have a single 15K BTU roof-top unit that I have to kick on, too, to do the initial cool so that it doesn't take 8 hours to cool the camper down. This was the biggest 115v unit I could find anywhere. If I could have installed it near the middle of the camper it might be more effective.

You're going to want to look into Magne Curtains to help block the heat, if you don't already have something in place.

If you have 240v in your trailer look at getting an 18k BTU unit. Maybe my situation is an anomaly. Hopefully others can discuss a better scenario.

Thank you for that detailed information. I am checking out those curtains.

 

[richard cabesa]

Thank you. I guess I misjudged big time. I have to scramble for a solution now.

I like every reply in this thread no matter if it is “works great!” - “doesn’t work”

it lets me evaluate my systems vs. uses

Yesterday it hit 105* outside of Sonora, Ca from 3-6PM. We ran the 4000w Onan for most of those hours to provide 1400 -1500 watts (plus surge) to the typical Dometic 13,500 btu rooftop unit.

that’s great. except for the noise of both the gen and the Dometic
We cannot stand that noise any longer
so we have decided to head down this mini-split path and see what happens

 

[Generis]

Thanks to all for the constant updates and questions. Really good info coming here.
A small update on my stuff, from the first post:

We had 3 days of solid rain. Very odd here. I noticed a few hours each day with lighter broken clouds, but really no good sun at all to speak of. And Hot.
The day temps were around 93 and down to 75 at night. And little regeneration. High humidity.

Oddly, the AC never gave in nor did the power systems, and after the 3 days the battery level was down only 240ah out of my capacity. That's interesting, as it was likely creating enough solar in the rain to keep up with the load... Very interesting.
I haven't had multiple long raining days such as these yet, at these temperatures. I'm glad for the test.

With that said, after the rain ended I got a full 800w+ power down for a hard long day. The controller managed a 47c internal temperature, and all the wiring to the battery got a noticeable but safe heat rise. It was working hard for maybe 5hrs. No reason to doubt the system reliability.

We are back to 80deg here now, and that's easily managed with my system in rain or shine.

I will say, you all in the 100+ deg heat have some more thought to put in... compared to our northern temps of rarely over 90. Our 9k Senville has no issues at all with our heat load. It's barely trying.
Best of luck! But it CAN work!

 

[K8MEJ]

I like every reply in this thread no matter if it is “works great!” - “doesn’t work”

it lets me evaluate my systems vs. uses

Yesterday it hit 105* outside of Sonora, Ca from 3-6PM. We ran the 4000w Onan for most of those hours to provide 1400 -1500 watts (plus surge) to the typical Dometic 13,500 btu rooftop unit.

that’s great. except for the noise of both the gen and the Dometic
We cannot stand that noise any longer
so we have decided to head down this mini-split path and see what happens

I have a Dometic 15K rooftop unit. It's so loud we can hardly stand it, too, when we're trying to sit at the table and talk or watch the news on TV. For now it remains on the roof. Why? Because my 12K LG mini-split is installed in the front bedroom on the only wall in the camper with enough room that isn't in a slide. So, I need a fan to circulate the air toward the rear. Also, even on it's supposedly turbo setting, it takes a while to cool the camper down. The other day when it was 91 degrees with 70 percent humidity I ran both A/Cs to quickly cool the unit down. The 3KVA Victron Multi-Plus handled the load but the batteries got quite a workout.

Once the RV is cooled down, the mini-split does fine, but still needs the fan to get air to the back of the camper because of my installation location. Yesterday it was about 93 and 65% humidity (just awful) and I had to plug the camper in because it was cloudy. I can't go a full day on 560Ah with the fridge running (DC compressor), AC (pulls 500-600 watts in this weather), and the fan running full time. I had to plug in yesterday because I was at 13% SoC. In milder weather or full sun I can make it. I have more battery cells on order and if I remove the rooftop AC I can put at least 400 watts more solar on the roof to get me to an even 2,000 watts.

My windows aren't insulated on the RV but higher-end units often have dual pane windows. I think that would help a lot. Ray on the Love your RV YouTube channel recently showed a woven mesh screen material he puts on the outside of his camper to cut down on the heat entering the RV. I'm going to look into that.

P.S. If you have 240 volts in your RV then I strongly recommend you go with a 240v mini-split. There are far more options available than there are 120v mini splits.

 

[bigguy6907]

Thanks, you're right, it's $900:

LG - 12k BTU Cooling + Heating - Mega 115V Wall Mounted Air Conditioning System - 19.0 SEER

LG LS120HXV2 - 12k Cooling + Heating - 115V Wall Mounted - Air Conditioning System - 19.0 SEER2

Buy LG LS120HXV2 Today. Free Shipping. Check the LG - 12k Cooling + Heating - 115V Wall Mounted - Air Conditioning System - 19.0 SEER2 ratings before checking out.

www.ecomfort.com

Just found another 12k at 120V ($768):
Klimaire 12,000 BTU KSIV 19 SEER Ductless Mini-Split Inverter Air Conditioner Heat Pump System with 15-ft Installation Kit and Wall Bracket 115V

https://www.amazon.com/Klimaire-Ductless-Mini-Split-Conditioner-Installation/dp/B07TDR51BW/

And another one ($798):
PIONEER® DIAMANTE SERIES 12,000 BTU 20 SEER 115V DUCTLESS MINI-SPLIT AIR CONDITIONER HEAT PUMP FULL SET WITH 16 FT. KIT

Pioneer® Diamante Pro Series 12,000 BTU 19 SEER2 Ductless Mini-Split Air Conditioner Inverter+ Heat Pump Full Set 115V with 16 Ft. Kit

Pioneer® Diamante Pro series. Extremely quiet, highly efficient. Finally, an affordable 12,000 BTU 115V Ductless Mini Split Air Conditioner Inverter Heat Pump!

www.pioneerminisplit.com

The space I have to condition is just 8' by 20' = 160 sq. ft. The 9k BTU units claim up to 400 sq. ft or even 500 sq. ft so I can't see needing to go to the 12k unit.

It also depends on other factors, like climate, direct sunlight, insulations, # of people in the space, cooking appliances used, including coffee pot.

 

[bigguy6907]

Just discovered a hybrid mini-split unit. It runs on DC and AC:

"This is the 5th generation of our ACDC12x solar air conditioner series with a new key feature we've had so many requests for - our new "C" model ACDC12C solar air conditioning technology requires no grid connection. Like previous versions, it also needs no batteries, no inverter, no charge controller - just plug in the solar panels and start saving up to 100% on daytime cooling or heating costs. A grid connection can be added to automatically allow operation at night, as well as to provide higher daytime capacity & uninterrupted operation during cloudy or low sunlight conditions. See ACDC12C Spec Sheet

During the day the ACDC12C can run exclusively on solar power with no AC power or grid connection when solar is strong enough. The maximum speed/capacity will be based on the level of available solar power available. If also connected to AC power source, the unit can run at full speed whenever needed, and will add in just enough AC power, if/as needed, while still primarily using available solar DC power."

DC Solar Air Conditioner Heat Pump | Solar Air Conditioning | Solar Heating | Manufacturers

The problem with these unit is that they require 100-300vdc. They are heading in the right direction, but not there yet. Thanks. We need 24 or 48 vdc and 110vac as options.