diy solar

diy solar

Cinergi's 28 kWh / 4 kW Solar / 10 kW inverter RV build

David S said:
This is exactly what I'm doing, removing the genset (a 6kW Onan Diesel) and replacing it with an ODU driving 2x 9k BTU wall mounts. My biggest challenge with the cassettes is that I'd have to enlarge the existing A/C holes from 14x14" to 24x24". I'm trying real, real hard not to mess with the roof structure if I can. It's all aluminum trusses and cutting it feels like a bad idea. Oh, I'm working on a super C motorhome, not a 5er, so that could be affecting my perspective too.
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Yeah I'm worried about the same, but I have already reinforced the entire roof with unistrut, so im thinking if i cut one roof strut to get the unit in place, it won't be the end of the world. Rv manufactures are notorious for having very uneven stud placement, sometimes from 32-44" apart.

Do they make ceiling cassettes smaller than 24"?
 
Lt.Dan said:
Yeah I'm worried about the same, but I have already reinforced the entire roof with unistrut, so im thinking if i cut one roof strut to get the unit in place, it won't be the end of the world. Rv manufactures are notorious for having very uneven stud placement, sometimes from 32-44" apart.

Do they make ceiling cassettes smaller than 24"?
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In my limited internet search, I've never seen anything other than 24x24". But who knows?
 
I've been spec'ing/installing these for a decade and have never seen a ceiling mount indoor unit less than 24"x24"... but plenty larger.

Also OP, that factory install is impressive... *Very* nicely integrated ODU. Thanks for posting those pics!

Edit: I sit corrected, Mitsu makes one marketed to fit between 16" OC joints, but it's quite a long rectangle. Still perhaps helpful for some here?

Ceiling Cassette Mini Split AC & Heat Units | Mitsubishi Electric HVAC

Choose between sleek recessed ceiling cassettes and suspended units with ceiling HVAC options from Mitsubishi Electric. Manage air flow with individual vent controls.
www.mitsubishicomfort.com www.mitsubishicomfort.com

Looks like they got away from their original "EZ Fit" marketing nomenclature. They're about 3.5' long, and applicable models start with MLZ-KP*
hvacdirect.com

12,000 BTU Ceiling Cassette Mitsubishi Mini-Split Multi Zone KP Series - Air Handler

With its enhanced operation features, the Mitsubishi MLZ-KP12NA ceiling cassette air handler provides superior heating and cooling to your room when paired with a compatible condenser, living up to Mitsubishi’s industry-leading comfort standards.
hvacdirect.com hvacdirect.com
 
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Euro 230V single phase is indeed different than our 240V split phase, but the ODU’s don’t know the difference. They see the 240V RMS L-L differential. Most brands give a pretty generous ~20% allowable voltage range. Sadly very few units can take 120V though, meaning we’d need two of most brand’s inverters to have be able to retrofit in a ductless mini solution. Otherwise, I’m a big fan of the 38-SEER (no typo) single zone model Gree offers.
 
cinergi said:
So it's about 82F outside, full afternoon sun (good heat load on the side of the RV), and I just set both cassettes to max and I'm drawing 700 watts. I can't wait to see what a 90+ degree day is like cuz that's awesome!
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Damn that's cool!!!
 
Only 700W?! Nice!!! If you can measure inside supply/return temps and RH, could also calculate output for ya.
 
I wanted to see how much solar I can produce ... I haven't been able to because my battery goes full on sunny days ... so I wasted a lot of power last night and today and ... drumroll ... 24 kWh of solar production on a sunny day in Connecticut in June. That's over 7 solar hours at rated output with flat-mounted panels. WOW!
 
cinergi said:
I wanted to see how much solar I can produce ... I haven't been able to because my battery goes full on sunny days ... so I wasted a lot of power last night and today and ... drumroll ... 24 kWh of solar production on a sunny day in Connecticut in June. That's over 7 solar hours at rated output with flat-mounted panels. WOW!
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The Victron shunt reading must be wrong ..... ;) ..... Just kidding.

You put your system together in a very meticulous fashion and it seems to be paying off even better than expected. (y)
 
And that's why I decided to basically repro his system, living vicariously through his research and methodically well executed plan.


.
 
The system is getting a workout here in Indiana! It's been 95 and humid for several days with partly sunny skies. I'm slowly running out of juice - but I have yet to plug in. I woke up with 48% this morning, got to 63% (it only got up to ~85 degrees & humid today, partly sunny and rainy).. now at 57% and will probably wake up with 30% ... but tomorrow is 100% rain all day and I may need to plug in for the first time ever :cry::cry::cry:

So, in light of that, I finally installed the Progressive Industries EMS-LCHW50 electrical management system to protect my Victron's from Bad Stuff at the Campground... I tested that I can plug into 50a or 30a no problems and it passes through properly to the Victron and they do the right thing whether on 50 (split phase) or 30 (single phase). So I'm ready. I'm gonna try not to plug in. I'm at almost 3 months now without plugging in.

I'm on my way to Kanas (where New Horizons - the 5th wheel manufacturer - is headquartered)... I'll be there the week of July 13th ... a few things on my list will be done, including upgrading my LR AC from 9k to 12k ... it definitely needs it. I'm not even convinced 12k is enough if you're gonna camp in temps over 95 degrees but a 33% increase in BTU should help a lot. The LR got up to 77 when I closed off and shut down the bedroom ... I have to use the bedroom + a fan in order to get the LR down to the low 70's when it's in the 90s right now.

And speaking of all that, the AC was running the hardest I've run it ... both 9k units running at max, consuming about 1000 watts of AC power. Right now I have the BR turned off and the LR set to 64 and I'm consuming about 200 watts of power for the AC (430 watts total for everything in the rig right now). It's now an hour after sunset and it's been raining and it's quickly dropped to 73 degrees outside. 68 and dry and QUIET inside :love:
The BR is 80 degrees haha but it will cool off quickly when I go to bed and turn on the AC there.

I leave the AC in the LR set to 74 when I go to bed. I typically use about 25% of my battery between sunset and sunrise (or about 30% from peak high to peak low). You can see all the graph/data here: https://vrm.victronenergy.com/installation/76892/share/d5bbdd04 -- go to advanced and you can see some really nice information about my power consumption etc ... and yes, my battery is getting too hot (due to outside temps, not due to charge/discharge). I just received the parts I need to pull the cool air from inside to the battery area.

Last two days if you're too lazy to hit the VRM URL :)

2021-06-30.png
 
What is your average R value on this unit? Typical 2" sidewalls? Single pane windows? I am going through the feasibility calcs for a off grid trailer/camper, and a used 5th wheel may be a good starting place.

Thanks for keeping us updated.
 
2 inch foam in aluminum frame. I think roof is same. There is "real” insulation below. The unit is guaranteed not to freeze above -10F

9k would be enough for this SQ FT living room but the insulation and windows (single pane) requires more. High ceilings too. And the slide outs have even more insulation gaps. The FLIR image in the winter was interesting. I’ll try to get one when it’s hot out. I may eventually try to improve the insulation.
 
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