Della Mini Split vs MRCOOL: Which Is Better? (November 2026)
The DELLA Vario Series 36000 BTU Mini Split is the better overall pick for most large rooms, with 19 SEER2 efficiency and coverage up to 2,500 sq ft. Choose the 12,000 BTU Vario instead when you're cooling a smaller 550 sq ft space and want the higher 23 SEER2 rating.
On this page (7 sections)
The DELLA Vario Series 36000 BTU Mini Split is the better overall pick for most large rooms. It covers up to 2,500 sq ft, runs at 19 SEER2 and heats down to -4 F.
The 12,000 BTU Vario is the stronger fit for a smaller 550 sq ft room, where its 23 SEER2 rating pays off.
If you're weighing a della mini split vs mr cool system, the real question is what your room needs. Capacity, efficiency and installation rules decide more than the brand name on the box.
This comparison walks through both Della Vario units so you can see which one matches your space.
MRCOOL is a known name in ductless systems, and its lineup spans several efficiency tiers. The Della Vario series sits in the same conversation for anyone shopping mid-range inverter units.
Here, we focus on the two Vario models and the choices that separate them.
How do the two Della Vario systems compare side by side?
The 36,000 BTU Vario is the bigger, whole-floor system; the 12,000 BTU model is the compact room unit. Both use inverter compressors, run on 208–230V power and include a heat pump rated to -4 F.
| Feature | DELLA Vario 36000 BTU | DELLA Vario 12000 BTU |
|---|---|---|
| Cooling capacity | 36,000 BTU/h | 12,000 BTU/h |
| Efficiency | 19 SEER2 | 23 SEER2 |
| Heating | Heat pump to -4 F | Heat pump to -4 F, 9.5 HSPF |
| Coverage | Up to 2,500 sq ft | Up to 550 sq ft |
| Noise | As low as 36 dBa | As low as 28 dBa |
| Fuse size | 30A | 15A |
| Smart control | WiFi 2.4 GHz, Alexa | WiFi 2.4 GHz, Alexa, app |
| Installation | Professional required | Professional required |
The table shows the core gap: one unit is built for a large open space and the other for a single room. The smaller model wins on raw efficiency, while the larger one wins on reach.
Neither is a DIY install, and both carry Della's lifetime parts coverage when registered within 100 days.
A 12,000 BTU system handles a typical bedroom or small living room. The 36,000 BTU system steps up to a large great room or an open-plan floor.
Choosing between them is mostly about square footage, not brand.
One spec worth reading closely is the noise figure. The larger unit lists a low of 36 dBa and a maximum of 52 db, so it is quiet at its lowest fan setting but audible when pushed.
The smaller unit lists 28 dBa as its low end, which is the quieter of the two for a room you sleep or work in. That gap tracks with the size difference: more air moved means more sound at the top end.
Which one fits your room size?
Match BTU to square footage first, because oversizing wastes energy and undersizing leaves hot spots. Della's own guidance makes the math simple.
Della pairs a 400 sq ft room with a 9,000 BTU mini split, a 550 sq ft room with 12,000 BTU and a 1,000 sq ft room with 18,000 BTU. The 36,000 BTU Vario is rated for up to 2,500 sq ft.
The 12,000 BTU model tops out at 550 sq ft.
That leaves a big middle ground. A 1,500 sq ft open-plan area sits closer to the 36,000 BTU unit, while a studio or spare bedroom belongs with the 12,000 BTU system.
If your room lands between the two, size up when ceilings are high or the space gets strong afternoon sun.
Our Della Vario 12000 BTU Mini Split review digs into how the smaller unit handles a single room. For sizing rules beyond these two models, pair the square footage with a quick load check before you order.
When the 36,000 BTU model makes sense
A large living area, a converted garage or an open-plan kitchen and family room fits the 36,000 BTU Vario. It moves enough air to reach corners that a single small head would miss.
The 36,000 BTU unit also suits a home that needs one system to cover a whole floor rather than one room. That's where its 2,500 sq ft ceiling and 30A fuse requirement come into play.
The indoor head measures 46.94 in wide by 14.19 in high by 10.25 in deep, so measure the wall you plan to mount it on before ordering. It weighs 39.7 pounds, so the mounting hardware and wall need to carry that weight safely.
When the 12,000 BTU model makes sense
A bedroom, office or small den under 550 sq ft is the natural home for the 12,000 BTU Vario. Its 15A fuse size also fits more household panels without a major upgrade.
The smaller unit runs quieter, at a listed 28 dBa, which matters in a bedroom. Its 23 SEER2 rating is the best efficiency figure between the two.
The indoor head is 31.92 in wide by 11.49 in high by 8.07 in deep and weighs 61 pounds. That footprint fits tighter walls, which helps in a room with limited clear space.
Which is more efficient, and does it matter?
The 12,000 BTU Vario is more efficient at 23 SEER2, but the 36,000 BTU unit still hits a strong 19 SEER2 for its size. SEER2 measures seasonal efficiency, so a higher number means less power for the same cooling.
Della says the inverter plus system and DC inverter technology deliver up to 30% power savings on the 36,000 BTU model. That's a maker claim, but the 19 SEER2 rating is the number that matters for comparison.
The 12,000 BTU unit lists 23 SEER2 and 9.5 HSPF for heating.
Higher SEER2 ratings usually cost more up front and pay back over years of use. In a room that runs most of the summer, the 23 SEER2 edge adds up.
In a large space that needs 36,000 BTU, there's no small unit that can do the job, so the 19 SEER2 figure is the practical benchmark.
What the two efficiency figures really mean
SEER2 is measured over a season of varying temperatures, not one fixed test point. A 23 SEER2 rating means the 12,000 BTU unit squeezes more cooling out of each unit of electricity across the year.
A 19 SEER2 rating on a 36,000 BTU system means each hour of running still costs more power in absolute terms, because the unit is three times the capacity.
That is why the efficiency comparison only makes sense within a size class. You would not swap a 12,000 BTU unit into a 2,000 sq ft room to chase 23 SEER2; it would run flat out and never keep up.
The right way to read the numbers is this: pick the capacity your room needs, then compare SEER2 among units of that size.
Check your local utility for rebate programs tied to SEER2. The efficiency gap between these two models is real, but capacity comes first.
How do they handle heating in cold weather?
Both Vario units heat down to -4 F (-20 C), so either works as a year-round system in most climates. The heat pump reverses the cooling cycle instead of relying on electric resistance strips.
The 12,000 BTU model lists 9.5 HSPF, a heating efficiency figure. The 36,000 BTU model uses the same heat pump approach and is rated to the same -4 F low.
Neither unit is a cold-climate specialty model, so in places that regularly drop below zero, plan a backup heat source.
A heat pump at -4 F still runs, but its capacity and efficiency taper as temperatures fall. For a mild-winter region, either unit covers heating and cooling in one box.
That dual function is a big part of the value, since you don't buy a separate heater.
If you're comparing against a brand like MRCOOL, check its exact cold-weather rating too. The -4 F figure is the number to hold both brands to.
A heat pump that stops at 5 F leaves you without heat on the coldest nights, so the low-end rating is one of the first specs to verify on any unit you shortlist.
What smart features come with each unit?
Both Vario models connect over 2.4 GHz WiFi and work with Alexa; the larger unit adds 4D airflow and turbo, while the smaller adds app control and self-cleaning. Smart features are close, but not identical.
The 36,000 BTU Vario includes 4D airflow that moves air up-down and left-right, an I Feel mode, a 24-hour programmable timer, sleep mode, eco energy-saving mode, multiple fan speeds and turbo. It also runs dedicated heating, cooling, drying and dehumidification modes.
Its smart sensor reads temperature at the remote instead of the indoor unit during cooling.
The 12,000 BTU Vario covers auto defrost, self-diagnosis and cleaning, I Feel mode, dehumidifying, a 24-hour timer, sleep mode, eco mode, multiple fan speeds and intelligent compressor pre-heating. It supports app and remote control.
How the smart sensor and app control work in practice
The I Feel mode is the feature that changes daily use the most. Instead of reading the air at the wall-mounted head, the system reads temperature at the remote, so the room feels right where you actually sit.
That matters in a large room where the head is far from the sofa, and it matters even more in a bedroom where the head is high on the wall and the bed sits lower.
App control adds scheduling from your phone, which is handy for turning the unit on before you get home. Both units need a 2.4 GHz connection; if your router runs a separate 5 GHz network, connect the unit to the 2.4 GHz one during setup.
For more on smart mini split features, see our Senville LETO vs Della Vario comparison.
Which is easier to install and live with?
Neither Vario unit is a DIY mini split, so budget for a licensed HVAC installer on either one. Della states both systems require professional installation.
The 36,000 BTU model needs a 30A maximum fuse, so check your electrical panel before you buy. The 12,000 BTU unit uses a 15A fuse, which is easier to accommodate in most homes.
Both run on 208–230V power.
Line-set length matters for refrigerant. Della says no refrigerant adjustment is needed if the tube run stays under 25 ft; longer runs require adjustment per the manual.
The 12,000 BTU unit includes a 16.4 ft installation kit with 1/4 in and 3/8 in copper pipes. The 36,000 BTU unit includes standard 1/4 in and 5/8 in pipes.
Both include a 78.7 in drain pipe. Line-set vacuuming is required during installation, so the installer needs a vacuum pump and gauges on site.
Coverage, registration and upkeep
Installation isn't the only living cost. Register within 100 days for Della's lifetime parts coverage.
HVAC-licensed installs get enhanced lifetime parts coverage; non-licensed installs get limited lifetime parts coverage. Coverage is for parts only and excludes labor.
For maintenance, clean the reusable dust filters seasonally, inspect the indoor and outdoor units and keep the condenser area clear. These steps keep airflow and efficiency steady.
A clogged filter is the most common cause of weak cooling on a ductless unit, and it costs nothing to fix.
Which should you buy?
Buy the DELLA Vario Series 36000 BTU Mini Split for a large room or open floor plan, and the 12,000 BTU Vario for a single room under 550 sq ft. The 36,000 BTU model takes the overall win because it covers far more space while still delivering strong 19 SEER2 efficiency.
The della mini split vs mr cool decision comes down to matching the system to your room. If your space needs 2,500 sq ft of reach and a 30A circuit, the larger Vario is the pick.
If you're cooling one bedroom or office and want the highest efficiency figure here, the 12,000 BTU unit fits better.
Either way, plan for professional installation and check the fuse size against your panel. For buyers still comparing brands, our Senville vs Pioneer Mini Split comparison and our Cooper & Hunter vs Pioneer Mini Split comparison cover the same choices for other systems.
Frequently asked questions
Is Della better than MRCOOL for a mini split?
Della is the stronger choice when you want a high-efficiency large-capacity system like the 36,000 BTU Vario, which covers up to 2,500 sq ft at 19 SEER2. MRCOOL is a well-known brand with many models, so match the exact SEER2, capacity and cold-weather rating to your room before deciding.
What size mini split do I need for my room?
Della's own guidance pairs 400 sq ft with a 9,000 BTU unit, 550 sq ft with 12,000 BTU and 1,000 sq ft with 18,000 BTU. The 36,000 BTU Vario is rated for up to 2,500 sq ft.
For open floor plans or hot climates, size slightly upward.
Can I install a Della mini split myself?
No. Della says both Vario systems require professional installation, and neither is a DIY mini split.
A licensed HVAC tech handles the line-set vacuuming and refrigerant checks.
Della offers lifetime parts coverage when you register within 100 days, with enhanced terms for licensed installs.
Does a Della mini split work in cold weather?
Both Vario models use a heat pump rated to work in temperatures as low as -4 F (-20 C). That covers most winters in mild to moderate climates.
In extreme cold, pair the heat pump with a backup heat source for the coldest nights.
What smart features do Della mini splits include?
Both Vario units connect over 2.4 GHz WiFi and work with Alexa. The 36,000 BTU model adds 4D airflow that moves air up-down and left-right, plus turbo, eco, sleep and a 24-hour timer.
The 12,000 BTU unit includes I Feel, self-cleaning and a 24-hour timer.
How do I maintain a Della mini split?
Clean the reusable dust filters seasonally, inspect the indoor and outdoor units and keep the area around the condenser clear. Register the unit within 100 days for lifetime parts coverage.
Della's coverage is for parts only and does not include labor.
