Interesting video about RV solar air conditioning

[wrybread]

I stumbled on this guy's videos, he says he's running an air conditioner 24/7/365 in his RV from solar:

There's a part 2 with slightly more details:

Actually at one point he says he turns it off if he has too many cloudy days in a row, which is of course fair enough, but he's running it most of the time.

An interesting detail is that he's using a "mini split" style air conditioner, which I gather is a lot more efficient than window bangers and especially than rooftop air conditioners, and probably a lot easier to install in an RV than a window banger. It pulls about 400 watts and is 9000 to 12000 BTU's. It also has a heater function, and can act as a dehumidifier. Here's Pioneer's version.

From another one of his videos I found that his RV has 8 180-watt panels = 1440 watts of panels (I'd probably reduce the number of panels and increase their wattage to at least 300 watt, but I guess it's a game of Tetris to find panels that fit well), 6 Battle Born 12v/100ah lithium iron phosphate batteries = 7200 watt hours (I'd probably use something cheaper than Battle Borne but they're certainly great batteries). I figure 1440 watts of panels and a 7200 watt hour battery bank is easily attainable for most RVs, especially larger ones, and especially when the rooftop air conditioner is gone. And the BTU's of that air conditioner are similar to roof mount AC's, as is the price (about $750).

He's running it from a 3000 watt inverter, and says it could be run off a 1000 watt inverter, but I'm curious if that's true without a "soft start" module.

I wonder if there's a roof mount air conditioner that's as efficient as a mini split? Or if a mini split could be mounted vertically using the hole from the stock rooftop AC? So much potential here for RVs.

 

[silversport]

He's running it from a 3000 watt inverter, and says it could be run off a 1000 watt inverter, but I'm curious if that's true without a "soft start" module.

I wonder if there's a roof mount air conditioner that's as efficient as a mini split? Or if a mini split could be mounted vertically using the hole from the stock rooftop AC? So much potential here for RVs.

I installed a 9000 Pioneer mini split in our bedroom, it pulls 5 amps even at start up, so yes you could get a way with a 1000 watt inverter (2800 watt Magna for us). Our front roof top rattle box I did install a soft start, our inverter will run it but barely (will be replacing in the near future with another split air). I thought out side the box on the installation, the condenser is on a lazy Susan to get the best air flow. The added bonus is the heat pump, it's so quiet we can sleep with it running.

 

[Lou Schneider]

Many inexpensive window air conditioners have soft start. The Mideas sold in Walmart and Home Depot do. A couple of years ago I bought a Fridgidare 5000 btu window unit for my shed that will start and run from a Sportsman 1000 watt inverter generator. Power draw after startup is about 400 watts.

One interesting alternative is a window mount a/c made for a double hung window, which has a U shape channel between the compressor and the inside unit for the window to lower into. Back in the 1980s I bought one of these second hand and since my mobile home had side sliding windows I cut down a solid core door to fill in the rest of the space. Now I'd probably use a solid foam insulating panel. 90% of a minisplit's advantages at about half the cost.

Here's one example that's Energy Star efficient and has a soft start. A friend installed the 10k btu model with an insulated panel replacing the rear window of his motorhome and he successfully runs it from his solar. Click on the picture for side and diagonal views.

Midea 8,000 BTU U-Shaped Inverter Window Air Conditioner WiFi, 9X Quieter, Over 35% Energy Savings ENERGY STAR MOST EFFICIENT MAW08V1QWT

 

[Lou Schneider]

I wonder if there's a roof mount air conditioner that's as efficient as a mini split? Or if a mini split could be mounted vertically using the hole from the stock rooftop AC? So much potential here for RVs.

Most of the inefficiency of a roof mount air conditioner comes from the large blower needed to force air in and out of the RV through the small 14" square roof opening. So anything else that uses that same opening would be equally inefficient.

 

[wrybread]

I thought out side the box on the installation, the condenser is on a lazy Susan to get the best air flow.

That's AWESOME! What a nice installation. I don't know much about mini splits, but looking at your install it looks like the two halves can be far apart and at different levels? Any disadvantages to that?

Many inexpensive window air conditioners have soft start.

I know, but they're a bit tricky to install in an RV. A mini-split just has a small hole (if I understand correctly). A window air conditioner requires cutting a giant hole in the side of an RV, or sacrificing some precious window space. And any hole you cut might need to be recut for the next air conditioner. I like the idea of window AC's, they're better than nothing, and better than trying to run a rooftop RV AC from battery, but they seem inferior to mini splits for RVs. And it sounds like mini splits don't require soft start at all (some at least).

Most of the inefficiency of a roof mount air conditioner comes from the large blower needed to force air in and out of the RV through the small 14" square roof opening. So anything else that uses that same opening would be equally inefficient.

But mini-splits use a much smaller hole than 14" square. If I understand them correctly that is.

 

[wrybread]

And check out this guy's sliding solar panel installation:

I found him when searching YouTube for "RV mini split air conditioner", which he has. He's got 8 300-watt solar panels on a tiny little roof! I hope this kind of installation becomes more common, it's a great solution for RV air conditioning (though large RVs with lots of roof space wouldn't need to do this). I don't think it needs the motorized system to deploy the panels, but that sure is nice. But making it manual would make it pretty cheap and a whole lot easier to build.

 

[silversport]

That's AWESOME! What a nice installation. I don't know much about mini splits, but looking at your install it looks like the two halves can be far apart and at different levels? Any disadvantages to that?

Yes two parts condenser and evaporator with two refrigerant lines and one electrical. the unit I installed, no more then 12 feet height differences (not a problem in a coach), came with 16 feet(?) of lines. A little challenging to hide lines but having the compressor in the bay big help in noise reduction.