Ask Dave: Using Solar With Your Mini-Split

Hey guys, Dave with Airspool here, and we have new Todd. Todd 2, not the Todd, but a Todd with Airspool LLC, and he's the Todd when it comes to sales and marketing. We're going to try something new: he's going to ask some questions, and we'll make videos based on your questions. Todd, without further ado, what do you got for me?

Todd: Hey, any questions you guys have, let me know, and Dave's going to answer them for you. Today we're talking about solar. So the question is: do I need solar panels connected and ready to go on my roof when I buy an Airspool mini split?

Dave: No. Next question. No.

Todd: Whoa.

Dave: It'll work just fine on normal grid power. We're talking about the 12,000 BTU units here, because that's our bread-and-butter unit; we also do 24,000 and multi-split, but let's first get a conceptual handle on things based on the MS12. It'll run 22.5 SEER on grid, which is super high efficiency, if you just plug it into a normal wall outlet. It'll run off-grid if you only have solar panels plugged into it. And if you have both plugged in, solar always gets prioritized. The unit has the smarts inside it to know what it needs. Say it needs 800 watts to run and there's only 300 watts of solar available at the time; 500 watts will come from the grid, but it will always take whatever solar is available and prioritize it.

Todd: So do people ever buy an Airspool mini split with the future intention of doing solar, and just use grid power for now?

Dave: Yeah. There are what's called MC4 connections on the outdoor unit. All solar, you love them or hate them, MC4 connectors are how solar panels connect to things, and it's boy, girl, click in. So if you never click in the panels, the unit is just a high-efficiency unit. But three years from now, it's your option, if you end up wanting to add solar and get a deal on panels. Right now, as of fall 2025, panels run around $400 to $600, plus any mounting hardware. It's not a huge investment. That's why we're doing this, to be able to run your air conditioning for free whenever it's sunny, your heating for free whenever it's sunny. The friction isn't really the cost of the panels, it's the cost of putting them up on your roof, the mounting. But if you can't get to that task right away, it's your option to add them whenever you want. If you want to add them, add them. If not, don't.

Todd: So do I need batteries in this whole setup? I know batteries are a big part of solar.

Dave: Yeah. The magic of this system is you just plug the panels in, click them onto the outdoor unit. The outdoor unit has an internal voltage controller, also known as an MPPT, maximum power point tracking. That's all internal to the unit, so you don't need any batteries. Why don't you need batteries? Because the grid is your battery. Batteries are expensive, and this unit will run off maybe one kilowatt-hour per hour, a little less than that, but at peak times, when it's super hot or super cold out, you'll need around one kilowatt, maybe a little more, and batteries would drain down in a hurry. The usable solar, even in summer on the longest days of the year, is maybe nine hours; come fall, we're getting into more like four hours being normal. So if you have grid power, use it. People who are off-grid still like these units, because they don't need to upgrade their batteries, their MPPT, or their inverter. So yes, nothing needed except the panels themselves, and probably some mounting, because if you just throw them on the ground, the wind will carry them away and you'll have a problem. But click them on and the unit will run.

Todd: So do the panels need to be close by the outdoor unit, like right on the roof above it, or can they be out in the yard? Is there a limit to how far away they can go?

Dave: There's not much of a limit. A wonderful tool for this is something you may have heard of called ChatGPT: you can say I'm 100 feet away, here's the voltage of my panels, and it'll answer you in five seconds. By the way, you connect panels in series, so the voltage is additive, which is actually a good thing, versus wiring in parallel where the current is additive. When the voltage is additive you're probably at least around 150 volts, so your current through the system at 1,000 watts is less than 10 amps. Say your panels are 100 feet away and you have 14-gauge wire, which sounds pretty thin for this; because the voltage is high, it'll still run just fine on that gauge. Your losses over that distance might be around 7 to 8 percent; at 30 feet it might only be 3 to 4 percent, and that's still some loss, but one $50 or $100 solar panel probably more than pays for running a thicker gauge wire instead. Really, most people are within 50 feet of where their solar arrays are. But if you live in the woods with tall trees around you, put the panels out in a field 100 feet away and it'll still work great for you.

Todd: Okay, so as far as buying them, where do you recommend people get panels?

Dave: What's happened in the last couple of years is the solar industry is changing. Up to this point, most of the people you've probably known, if you're a city slicker or suburb slicker, who went solar did so with a net-metered system, meaning they sell their extra power back to the grid and get a credit at night. But look at California, for example: starting in April 2023, you have to push up four kilowatt-hours to get about one kilowatt-hour credit back, and that's just a lousy rate of return.

Todd: So in that case you're basically giving three-quarters to the grid and getting a quarter back.

Dave: Right, and by the way, your power rates in California have also gone up over the last two years. So in a state like that, you're either taking it on the chin every year as PG&E's or Southern California Edison's rate keeps going up, or you get yourself some solar going. If you can get whole-house solar with a battery array, that's fine, but this system isn't meant to run your whole house. If you're in Bakersfield, the Inland Empire, or somewhere like Palm Springs where it's up to 100 degrees for many summer days and you're paying 50 cents or more a kilowatt-hour in the late afternoon, this is your low-hanging fruit for savings. Do whole-house solar, get yourself some batteries if you want, but this is a way to get set up. So, Todd, what was your original question before I started riffing?

Todd: I don't know, we lost it. That was my biggest thing that drew me to this: we have a 3,700 square foot house with a bunch of different bedrooms and everything else, too big, and you could probably walk by and tell me what units they are, two big central AC units. We spend here in Vegas the majority of our time in an 800 square foot kitchen and living room area, and the idea, like you were saying, is having it be supplementary to whole-home cooling, taking care of the majority of the bill in the part of the house you actually live in during the summer.

Dave: We have clients who have 12 units, and we have clients where the majority just have one. One guy in Costa Mesa, which isn't super hot there, but his wife likes it super cold upstairs where she's most of the time, they were having to run their whole 3.5-ton unit at 71 degrees and the bills were astronomical. By placing just one one-ton solar unit up where she runs it the hardest, and setting the other unit to 76 or 77, he's saving $150 a month off of that one unit. That's kind of an extreme California example based on his setup, but you get the idea: even one of these in your house in Arizona or California, and every degree you can raise your thermostat, say from 75 to 76, saves you a couple percent in energy. His situation had even bigger savings than that because of how things worked out for him.

Todd: So are there companies you'd recommend for getting solar panels, or other places to buy them?

Dave: Right, that was the original question. We're working on maybe doing panels ourselves in the future, probably flexible panels, we've introduced FeatherVolt and test-marketed some of that. The problem right now is we ship mostly via UPS, and you can't ship solar panels via UPS; they have to be palletized. Panels are just too heavy, big, glass, and can't ship via UPS. So we refer people to local places: Santan Solar in Gilbert, Arizona, and Green Tech Renewables, which is national. We also point people to Facebook Marketplace; a lot of times people order a pallet, because that's how panels have to ship, and they only needed eight panels, so they have six left over that they put on Facebook Marketplace. Of course they try to sell them for more than they paid, figuring they're in the solar business now, but realistically that's pretty negotiable. Even so, as of fall 2025 you're probably looking at around 30 cents a watt.

Todd: And how many watts do you recommend for the one-ton unit? I don't think we've talked about that yet.

Dave: For the one-ton unit, we recommend 1,500 watts. So 1,500 times 30 cents a watt works out to $450. If you're patient you can probably find it for even less than that, but it's a nice option to add solar for not quite nothing, but these days $450 doesn't go real far, and if it can cool at least 500 square feet of your home for free whenever it's sunny out for the next 25 years, that's not a bad opportunity.

Todd: So if I buy the panels, mounting hardware, and everything else on Facebook Marketplace, do I need to separately buy the MC4 cables that connect the panels to the outdoor unit or the isolator?

Dave: Every solar panel I've ever seen has a male and a female MC4 connector, so those daisy-chain together, boy to girl. We provide you with 10 meters, which is 32 feet 8 inches, of solar wire. One run is black and red, marked girl-boy on one side and boy-girl on the other, and that hooks right onto your solar array. We also provide an isolator, which is basically just an on-off switch for the solar; you always keep it on unless you're doing work on your unit. And we provide 54-inch whips that run from the outdoor unit to the bottom of the isolator. So we provide everything else besides the solar panels themselves and the mounting hardware for them.

Todd: Cool, I love it, dude. Is there anything else?

Dave: At your one-year work anniversary, I'll probably come up with a nice opportunity for you to get one at maybe 20 percent off. How's that sound?

Todd: I love it. Yep, I'm excited, start the countdown. Is there anything else, Dave, you want to share about solar?

Dave: Yeah, sort of. Whether you're interested in this or not, we see this as the future. Why? This is turning the alternating current in your home into direct current, and too many things now run on DC power. Edison was right, he was just 140 years too early. Your electric vehicle ultimately runs on DC power, your computer, your phone, your TV all run on DC power. This heat pump, the motors in this unit, run on DC power. Long term, there's probably going to be a DC node to plug all these different things into. As of now, it looks like that would be 350-volt DC, and there'd have to be some voltage conversion going on. So for anyone looking to make a career in the next five years, the future is DC-to-DC conversion. Plastics was the thing back in the 1960s; right now, I think it's DC-to-DC conversion.

A normal mini split runs on alternating current. Inverter mini splits run direct current internally, but if you plug one into a normal wall outlet, you're rectifying that alternating current to direct current, and there's a little bit of loss there. But solar panels are DC, the motors in this unit are DC, and so there's no conversion loss. That's going to be the future. At least here in the Southwest, there's plenty of sun to capture to run things for free. On the local level, you don't have the same overhead. The California utilities, for instance, are only allowed to make something like 10 to 12 percent profit, so if they're charging you 40 or 50 cents a kilowatt-hour, that means their actual cost is more like 25 to 40 cents a kilowatt-hour, just to stay within the California Public Utilities Commission threshold where they're only making that 12 percent. And that's because they have so much overhead, from past lawsuits, from grid maintenance, from a $14 million a year CEO's pay, and so on. But by just putting a few panels up on your roof, it's the least expensive form of power you can have to run these devices in the future. Right now, with 1,500 watts, you can run this all day long for free for the next 25 years.

Todd: We got an email, or a comment, from someone who likes to unplug their unit from the grid just for fun during the day and then plug it back in at night, just because it's so novel that it's pumping AC for free and the electronics are lit up.

Dave: This is new technology. In the old systems, everything was 48 volts, so they ran off four batteries, and you needed to charge those. There was a voltage controller and an inverter, but they used a special type of compressor to run on 48 volts, so that compressor was more expensive. What we're really doing here is taking off-the-shelf inverter compressor technology and doing some special electronics that allow this blending of AC and DC. The heat, by the way, isn't what produces solar power; it's the photons hitting the solar panels, the light, not the heat. In fact, heat is bad for panels; when it gets hot out, they actually become less efficient. But the first time you see this running totally unconnected from the grid, it's pretty magical, cold air coming out with nothing plugged in.

Todd: Yeah, that's pretty wild, having it all lit up and pumping cold air with nothing plugged in.

Todd: Well, cool, Dave. All right, man, thank you, this is good. For everyone else, if you have questions you want Dave to answer about anything in this space, he's happy to.

Dave: This is a new industry, so we're going to work to answer the questions we probably get the most of, but shoot us your questions, and if they seem like something others might want answered too, we will work to address it. Thanks for your time.

Todd: Love it. All right, till next time. Thanks.