The correct line set size depends on your mini split system. Always refer to the manufacturer’s specifications to ensure compatibility.
Measure the distance between your indoor and outdoor units
When in doubt, choose a longer line set. Most systems require a minimum length of 15 feet to function correctly, while exceeding the manufacturer’s maximum limit can cause performance issues.
For more information, check out our complete guide to line sets for mini splits
What voltage do I need?
The voltage you need depends on your home’s electrical supply and the requirements of your mini split system.
Before installation, make sure your home’s available voltage matches the voltage listed for the unit.
Most mini split systems require either 115V or 208–230V power. Using the wrong voltage can cause performance issues or damage the unit.
If you are unsure, consult a licensed electrician before installation.
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Local rebates
Enter the ZIP code where this system will be installed to see current utility and government incentives.
Secure your year-round comfort for larger living spaces with this Optima Series Mini Split AC. Its high-performance heat pump provides dependable warmth in frigid conditions down to -13°F, while its powerful 12000 BTU cooling tames the summer heat with remarkable 23 SEER2 efficiency. This unit utilizes modern, eco-friendly R-454B refrigerant. As an Energy Star certified system, it may qualify for local rebates and is backed by our lifetime warranty for ultimate peace of mind.
How Long Will It Take for My Order to Ship? It normally takes us 1 business day to arrange the shipment. During peak seasons, it will take 2-4 business days to arrange the shipment. We provide free ground shipping, so there are no additional charges for shipping and handling.
How Do I Track My Order? Log into YOUR ACCOUNT, and you may see each individual order that you’ve placed with us. Select one that you want and you’ll be provided with all the details you need about the order.
Once your order is on the way you will receive a notification email.
What Should I Do If I Haven’t Received My Order? Please contact us immediately.
For the full shipping policy, click here to view our shipping policy. Return
We offer return guarantees to ensure your satisfaction with every DELLA purchase.
DELLA provides comprehensive assistance for all orders within 30 days of purchase. If you're not satisfied with your product within 30 days of purchase from dellahome.com, you can return the product for a full refund.Products must be returned in their original operating condition, including all accessories and packaging.The customer is responsible for return shipping costs.
If a product defect is confirmed, DELLA will, at its discretion, provide the necessary replacement parts free of charge. DELLA will also cover all shipping expenses for the delivery of replacement parts.
Need to Start a Return? To initiate a return, call us at (800) 863-4143 or contact our live chat team.
For full return terms, click here to view our return policy.
Standard Warranty (1 Year): Products are covered by a 1-year limited warranty from the date of purchase.
Extended Warranty Program: Customers whoregister their mini split unit within 100 days of purchase will receive complimentary lifetime parts coverage.
Registered Product and Non-professional Install: If a product defect is confirmed, DELLA will, at its discretion, provide the necessary replacement parts free of charge. The customer is responsible for all shipping costs.
Registered Product and Professional Install: If a product defect is confirmed, DELLA will, at its discretion, provide the necessary replacement parts free of charge. If, after parts are replaced, the customer’s unit is still malfunctioning and the customer has a licensed HVAC tech's defective report, Della will take care of the customer at its discretion. In any event, the customer is responsible for all shipping costs.
Unregistered Product: If a product defect is confirmed, DELLA will, at its discretion, provide the necessary replacement parts. The customer is responsible for the costs of all parts and shipping.
Optima: Cold Weather’s Greatest Rival. Efficiency’s New Standard.
Engineered with cutting-edge Hyper Heat technology, the Optima mini-split delivers reliable, high-performance heating even when temperatures plummet to -13°F. With an industry-leading 23-24 SEER2 rating and ENERGY STAR® certification, it’s designed to slash your utility bills while keeping your sanctuary cozy year-round. Whisper-quiet, smart-connected, and built for the extreme—Optima ensures your comfort (and savings) never freeze, no matter what’s happening outside.
Powered by MightAir X
Top performance, energy smart design
65% more efficient energy savings
Cleaner air, healthier living
Durable design, lasting comfort
Reliable Performance in Extreme Weather
Engineered to deliver dependable heating and cooling through intense summer heat and freezing winter conditions, helping maintain consistent comfort when outdoor temperatures become more demanding.
6 modes for max comfort
Auto mode
Maintain a comfortable indoor temperature by automatically switching between heating and cooling as needed
Auto mode
Maintain a comfortable indoor temperature by automatically switching between heating and cooling as needed
Wherever you are
Control your comfort, your way
Set schedules and timers through the Della+ app to match your daily routine.
Take control your way through the app, remote, or voice. Award-winning remote design makes every interaction seamless.
Your comfort adjusts automatically as you come and go.
Get help anytime with live chat or call, directly in the app.
Control your AC hands-free with Alexa.
Which series is right for me?
Model
Efficiency
HSPF2 Rating (Region IV)
Refrigerant
Climate Range
Energy Rebate
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DELLA Optima Series 12000 BTU 23 SEER2 Ultra Heat Mini Split AC (R-454B) - Up to 550 Sq.Ft.
SEER2 23
10
R454B
-13°F - 131°F
DELLA Vario Series 12000 BTU 20.5 SEER2 Mini Split Heat Pump AC - Up to 550 Sq.Ft.
This unit uses R454B refrigerant. This unit comes pre-charged with R454B refrigerant for up to 24.5 feet of lineset. If your installation does not exceed this length, no additional refrigerant is needed.
R454B is a new-generation eco-friendly refrigerant that complies with EPA regulations. It can replace the original R410A models, offering better performance and greater energy efficiency.
Yes, you can purchase a longer lineset separately. If you buy it together with the Single Zone Mini split system, you’ll receive a 10% bundle discount. Please note, if the extended lineset is longer than 25 feet, additional refrigerant will be required. Make sure to consult a professional HVAC technician for proper installation.
In auto mode, the unit automatically switches between cooling and heating to maintain the set temperature. You can adjust the target temperature manually—typically between 60°F and 86°F —depending on your comfort.
The mini split condenser and lines are not pre-vacuumed. You will need to vacuum the system during installation to remove air and moisture before releasing the refrigerant—this is essential for proper operation and longevity. You can use our Rental Kit Service, which includes all the necessary tools for vacuuming and installing your mini split.
Talk to an HVAC expert
Not sure which system is right for your home? Our experts can help with sizing, installation, and product selection.
Technical support: Mon - Fri, 8 AM - 3 PM (PST)
24/7 live chat for general question
An Excellent DIY Mini-Split: Quiet, Powerful, and User-Friendly ?. As a first-time DIY installer, I am incredibly impressed with this mini-split system. The performance is outstanding, and the unit is exceptionally quiet. ?Installation: The included kit is comprehensive, providing almost everything needed for installation. However, for a clean and professional-looking result, you will need to purchase the following items separately: ?a drill and appropriate masonry, drywall, and wood bit, ?line set wall sleeve/guard ?Outdoor condenser wall mount. A vacuum pump and gauge set (essential for proper installation) ?. I highly recommend watching instructional videos on YouTube before starting. Ensure all connectors are securely tightened, the refrigerant lines are not kinked, and you perform a thorough leak check to avoid common installation errors and the need to add refrigerant. ?Performance: The unit operates at a whisper-quiet level, both the indoor air handler (even on its turbo setting) and the outdoor condenser. It is a significant improvement over my previous portable floor AC, which was disruptively loud. This unit effectively cools my room, which has a west-facing window and would previously reach temperatures as high as 98F. Now, the room temperature can comfortably be lowered to 63F. ?Features: The accompanying mobile app has a clean, user-friendly interface that is simple to navigate. ?Overall, I highly recommend this unit for its exceptional performance, quiet operation, and affordable, manageable DIY installation process
I do not write reviews much, but this mini split is worth it. I purchased my Della 12k BTU unit a few months ago. I'm a DIY guy but was a little nervous installing this unit, as some of the information online made it seem difficult. Once I received our mini-split and unpacked everything, installation was easier than expected. I do want to note that you will need a vacuum pump and a set of A/C gauges. Once the unit was installed and running, my spouse and I were amazed at how quickly it cools off the 3 floor of our house. We do have central heating and air, but the 3 floor is constantly warm in the summer. After the first month of the unit running, we received our electric bill, and I was surprised that we saved 4 kilowatt-hours per day and our bill was $37.00 cheaper than the previous month. We just received our bill for July, and it's $43.00 cheaper than June, and we kept the house at 70 degrees both months. I would definitely recommend the Della 12,000 BTU mini-split unit to friends and family!
Not disappointed. Installs easily and works per design. This heat pump puts out a large volume of heat quickly. I'm delighted to say I have a heated garage! This is my second DELLA heat pump I've installed for myself.
So far this has been great. The app is what really makes it great. We've installed this on the food truck, and I can see the ambient temperature and perform a self-clean while at the office. We haven't used it through summer yet, but it has done great as a heater and for keeping the truck cool after a shift.
We have a back sun room with lots of windows. I was either blistering hot in there or freezing cold. We had this unit installed, and now we can enjoy this sun room all year round!
I have now installed 4 of these units. With a vacuum pump and a set of gauges, you can easily install these for much cheaper than hiring someone to do it.
The installation was super easy and the instructions were very clear. It took my son and I around 5 hours to install and that was taking our time. Neither of us have any HVAC experience. I wish that you could make the instructions for using the remote a little clearer.
My second Della and I will continue to buy Della mini splits for the simple reason - customer service, they truly stand by you. I brought my first Della two years ago, had to call Della for help, they were there. Two year later same service person helped me. Incredible, they remembered me, I remembered them. Because of the retention and energy and sincerity of the service people of Della, I am convinced that they kind of energy and commitment is translated into their products. So far I am absolutely correct!
System was easy to install and works fantastic! The indoor and outdoor unit are both super quiet. Only wish that the unit was shipped together and not from two different locations. Had a 3-4 day wait from receiving the indoor unit and then the outdoor unit.
I was replacing a ten year old Mitsubishi unit. Everything went well. My only thing is the bracket for the inside unit. I would like it to span wider to allow easier securing to studs. Now, I am considering one for my shop.