You might remember that we previously reviewed the EG4 Hybrid Solar Mini-Split. When we first got our hands on it, we were pretty impressed with its performance and the promise of a ductless air conditioner and heat pump that could run directly off solar.
Since that first review, we’ve been using the EG4 Mini-Split every single day to heat and cool our garage. This space also doubles as one of our primary filming and testing spaces, so temperature control is really important to us.
With this review, we’re going to revisit EG4’s Hybrid Mini Split. We’ll break down how it’s been working for us over the past year, how it has saved us a ton of money on utility bills, and how you can set up a similar system, regardless of if you're fully off-grid, or you're just looking to cut down on your electricity bills.
Before installing the EG4 Mini-Split, we relied on a 15 kW electric heater in the winter and a combination of portable air conditioners and fans in the summer. It was loud, inefficient, expensive to run, and definitely not ideal for filming our review videos.
Since installing our mini-split, our garage is now comfortable during every season. The best part? We don’t pay a dime to run it. The system is tied into the solar panels in our backyard, as well as a dedicated off-grid battery bank and inverter setup inside the garage.
Basically, we can run our EG4 Mini-Split entirely on solar, either directly from the panels, or with solar power stored in our batteries. Since it runs entirely on free electricity, there’s no impact on our monthly utility bills.
We recognize that not everyone is going to have a full backyard solar panel setup, but even if you don’t have the same solar capacity that we do, you could still build a smaller, more affordable solar panel array that would deliver similar results. That’s really the beauty of going with something like a mini split air conditioner and heat pump.
A mini-split is essentially a high-efficiency, ductless heat pump. Instead of running ducts throughout a home or business, you install an indoor air handler (which circulates warm or cool air) and an outdoor condenser (which manages the refrigerant cycle).
Here’s what makes the EG4 Mini-Split stand out:
Unlike a standard mini-split, the EG4 Mini-Split can directly run on DC power. This means you can connect solar panels straight into the unit. There’s no need for an inverter, so it is far more efficient than a traditional air conditioner or heater.
Not only can it run on solar power directly, you can even set the system up to prioritize solar power when it is available, then automatically switch to grid power as a backup. Again, you save money by prioritizing free solar power, but you don’t have to worry about your indoor space heating up or cooling down if your solar panels are not generating enough power, or your solar batteries are fully drained.
Speaking of setting up the solar mode, you can adjust all of these settings directly with the included remote control or through the EG4 App on your phone or tablet.
Being able to easily adjust temperatures, fan speeds, and all of the other modes from anywhere is really convenient. The monitoring features also allow you to track the system’s solar usage, as well as pre-cool or pre-heat spaces before you step into them
For us, this is amazing. If we know we’re going to be filming a review or testing a power station in the garage, we can bring the temperature up or down to a comfortable level ahead of time. We save power, and we don’t have to worry about Tiny Baby sweating or shivering while we’re trying to work — it’s a win-win.
EG4 also offers a few different versions of the system, allowing you to choose the right size based on your space and needs. We use the 24,000 BTU version to cover our three-car garage, but those with a smaller space (or smaller solar panel setup) could choose something like their 12,000 BTU Mini Split.
These smaller units use less power, take up less space, and they’re quite a bit cheaper. EG4 giving buyers the option to pick a unit that meets their exact needs is a level of flexibility that we haven’t really noticed from other mini-split brands.
Unlike a traditional HVAC system that is either fully on or fully off, this EG4 Mini Split has a built-in inverter compressor that can throttle power up or down depending on the temperature and your preferred settings. That makes it both quiet and extremely efficient.
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We’ve built out a dedicated off-grid system in the garage to run the EG4 Mini-Split and power any gear that we’re testing. Here’s what it looks like today:
This relatively simple setup means all of our backyard solar power feeds into the batteries, and their first job is to keep the garage climate controlled through the EG4 Mini-Split.
Since we generate more power than we use, our batteries rarely dip below 90% state of charge, so we could easily run this same setup with fewer solar panels and server rack batteries.
Yes, it’s oversized and not “perfectly optimized”, but this entire off-grid power system was originally designed for testing solar equipment and power stations. The point is, whether it’s summer or winter, the garage stays comfortable and we don’t have to pay for power, or worry about grid outages.
After running our EG4 24K Hybrid Mini-Split day in and day out for more than a year, here’s what we’ve noticed:
Mini-splits don’t instantly blast hot or cold air into an environment. They’re far better at maintaining comfortable temperatures when left running consistently. We tend to let ours run in the background, even if we don’t plan on using the garage. Fortunately, we don’t have to pay to use it, so there’s really no harm in letting it run day and night.
Once the garage is up (or down) to our desired temperature, the EG4 Mini-Split automatically throttles back and uses very little power to keep it there. For those with smaller battery banks or solar panel setups, this would be really beneficial.
Unlike our old heater or the portable ACs we were using, the unit is practically whisper-quiet. When it’s running, all we really hear is the fan noise, which is very mild compared to a traditional air conditioner or space heater. This is perfect for filming in the garage.
It also works perfectly, and we have never even noticed as much as a hiccup in the performance.
With solar + battery storage, we haven’t paid a dime to heat or cool the garage. Keep in mind this was a major expense before we installed the EG4 Mini-Split.
Not everyone needs (or has the budget for) a massive 15kW solar array. Luckily, the EG4 Mini-Split is efficient enough to run on much smaller systems.
If you’re looking to build out a system on a budget, we’d definitely recommend starting with the EG4 Mini-Split itself. Even plugged into the grid, it’s far more efficient than a space heater or window AC. Buying this first piece of euqipment also gets you started on the right path.
From there, add solar power gradually. About 2,500W of solar panels would be enough to handle daytime loads. You can also mount your solar panels on cheap ground mounts or solar panel racks if you’re not prepared for a full rooftop setup.
We recently reviewed the dirt-cheap PowerField PowerRacks and the new IntegraRack Solar Panel Ground Mounts, which would both be affordable options. You can also watch our Top 5 DIY Solar Panel Mounts Video for more information on affordable, beginner-friendly alternatives.
Once you have your solar panels installed, you can wire them directly to your EG4 Mini-Split. It will then automatically run on solar power when it’s available, and switch back to grid power when it isn’t.
The next step would be investing in a cheap battery bank. Even a modest set of wall-mounted or server rack batteries would allow you to store solar power, so you could run your mini-split on solar electricity at night and during cloudy days.
Not only can you pick these components up over time, so you space out the expenses, it’s really easy to build and doing so allows you to start efficiently cooling and heating your indoor space right away.
If you’re interested in buying one of these, we’d highly recommend checking out Signature Solar. They carry the EG4 Mini-Splits, and also offer mini-split homesteading bundles, which package the unit with solar panels and all of the wires and connectors you’d need.
On top of that, Signature Solar has genuinely helpful customer support. We’ve mystery-shopped them before, and their team was great at walking us through sizing and troubleshooting questions.
Pro Tip: Make sure you get the version with solar input plugs and solar-first mode so it can automatically switch between solar, batteries, and grid without extra management. If you’re unsure what this means, just call them. They’ll walk you through what you need, as well as answer any other question you may have.
Absolutely! The EG4 Mini-Split has been one of the most impactful solar upgrades we’ve made to The Solar Lab. We use a lot of the products we test here (the good ones), but few have actually ended up being as adopted into our daily routine.
This mini-split is efficient, reliable, practical, quiet, and most importantly, it saves us a ton of money. Whether you’re trying to heat a garage, cabin, workshop, or off-grid home, this ductless heat pump is a fantastic option.
If you want the flexibility of solar-first operation and the peace of mind of affordable year-round comfort, we can say with confidence that the EG4 Mini-Split is tough to beat.
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