Della 18K BTU 2-Zone Cassette Review (2026): A Spec-Based Look

What stands out

• 24 SEER2 efficiency rating for reduced energy consumption
• Dual-zone design with two 9,000 BTU indoor units
• 360-degree surround airflow for even room distribution
• Heat pump operation down to -13°F (-25°C)
• Quiet operation at just 32 dB(A)

Who it fits

Key specs explained for this unit

Cooling Capacity: 18,000 BTU/h

This value indicates the total cooling power of the system. You get two indoor units, each providing 9,000 BTU. This capacity is suitable for spaces up to 800 square feet combined. If your rooms are larger, you may need a higher capacity model. It ensures the air feels cool without overworking the compressor during typical summer days.

Efficiency Rating: 24 SEER2

SEER2 measures seasonal energy efficiency for cooling. A 24 rating is high, meaning the unit uses less electricity to produce the same cooling output. You will likely see lower monthly energy bills compared to older or lower-rated units. This metric helps you compare running costs against other mini splits in the same capacity range.

Number of Zones: 2 Zone

This system controls two separate areas independently. You can set different temperatures for each room using individual controllers. This is useful if one room is sunny and the other is shaded. You avoid wasting energy cooling unoccupied spaces. It offers more comfort flexibility than single-zone systems that treat the whole house as one area.

Heat Pump: Heat Pump

The unit provides both cooling and heating. It moves heat from outside to inside during winter. The listing notes operation down to -13°F. This allows year-round comfort without a separate heater. You get a single system for all seasons. Check if your local climate requires backup heat for extreme cold beyond this rated limit.

Design and build overview

The indoor cassette units measure 22.5 inches by 22.5 inches with a height of 9.63 inches. They are white and weigh 32 pounds each. The compact square form fits into standard ceiling plenums. This layout keeps the unit hidden from view while allowing air to circulate evenly. You get two separate indoor units, each rated for 9,000 BTU. This split design helps you target specific rooms without wasting energy on unoccupied spaces.

The system includes a refrigerant leak sensor for added safety. You can control each zone independently using the included separate controllers. The listing also notes compatibility with the DELLA App and multiple voice assistants. This connectivity lets you adjust temperatures remotely. The outdoor unit features a bottom heating element to prevent ice buildup during winter. This design choice supports reliable defrosting and consistent heating performance in cold conditions.

According to the listing, the unit operates at 32 dB(A). This low noise level ensures it runs quietly. The sleek white finish blends into most interior designs. You must ensure proper installation, including vacuuming the line set. Professional installation is mandatory for this model. The physical design prioritizes space efficiency and discreet operation. This makes it suitable for offices, shops, or homes where ceiling space is available. The dual-zone structure allows you to customize comfort levels in different areas.

Installation and daily operation details

This unit requires professional installation. You cannot set this up yourself. The line set must be properly evacuated and vacuumed during the process. The system is designed for ceiling mounting, so you need a compatible plenum space. The indoor units are white and fit into standard ceiling layouts. You get two separate controllers, one for each zone. This allows you to set different temperatures for each room independently. The system supports 208-230 V power. You must ensure your electrical setup can handle the maximum fuse size of 25A. For daily use, you control the unit via the included controllers or the DELLA app. The app also connects with multiple voice assistants. You can adjust settings from anywhere. The system offers several modes, including cooling, heating, dehumidifying, and auto. You can also use the 24-hour timer for scheduled operation. The unit runs at 32 dB(A), which is quiet enough for offices or shops. It features 360-degree airflow for even distribution. The outdoor unit includes a bottom heating element to prevent ice buildup in winter. This helps with efficient defrosting when temperatures drop to -13°F. You do not need to worry about manual defrosting. The inverter technology adjusts power usage automatically. This helps save energy while maintaining your set temperature. You simply select your preferred fan speed and mode. The system handles the rest.

Before you buy this unit

You need to confirm your electrical panel can handle a 25-amp maximum fuse size. The unit requires 208-230 V power, so verify your home’s voltage matches these specifications. Since this is a dual-zone system, you must ensure you have space for two indoor cassettes and one outdoor compressor. The indoor units measure 22.5 inches square, so check your ceiling plenum dimensions carefully. You should also plan for professional installation, as the system mandates proper evacuation and vacuuming of the line set. This setup is ideal if you need independent temperature control for two separate rooms, each up to 400 square feet. Unlike single-zone models, this option covers up to 800 square feet total. It fits well alongside other commercial-grade units if you need strong heating down to -13 degrees Fahrenheit. Check that your smart home ecosystem supports the DELLA app and voice assistants if remote control is important to you.

Check before you buy

• Verify your electrical panel supports 208-230 V and a 25-amp fuse.
• Measure your ceiling plenum to ensure it fits the 22.5-inch square units.
• Confirm you have space for two indoor cassettes and one outdoor unit.
• Check if your smart home supports the DELLA app or voice assistants.

The product at a glance

1

DELLA 18K BTU 2-Zone Cassette

Best for: Two-zone commercial or residential ceiling installations

Cooling Capacity

18,000 BTU

Efficiency Rating

24 SEER2

Voltage

208-230V

Coverage Area

Up to 800 sq ft

Number of Zones

2 Zone

Heat Pump

Heat Pump

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This Della mini split delivers 18,000 BTU of cooling across two 9,000 BTU zones. It features a 24 SEER2 efficiency rating and operates down to -13°F. The ceiling cassette design offers 360-degree airflow and runs quietly at 32 dB. You get independent control for each room via separate controllers. It includes a refrigerant leak sensor and smart app connectivity. This unit is built for commercial or residential spaces up to 800 square feet.

Pros

• 24 SEER2 efficiency rating for strong performance
• Dual-zone design with independent temperature control
• Quiet operation at 32 dB(A)
• Operates in temperatures as low as -13°F
• Includes refrigerant leak sensor for safety

Cons

• Requires professional installation; not a DIY unit
• Line set not included in the base package
• Maximum fuse size is limited to 25A

Good fit if

• You need independent climate control for two separate rooms
• You want a ceiling-mounted unit for a clean look
• You require heating performance in cold climates down to -13°F

Skip if

• You are looking for a DIY-friendly installation
• You need a single-zone system for one room
• You want the line set included in the box

Verdict: Della 18K BTU 2-Zone Cassette AC is a high-efficiency, dual-zone solution for spaces up to 800 square feet. It fits buyers who need quiet, independent zone control and professional-grade commercial features.

Specifications side by side

Frequently asked questions

See also

• della 18k btu 2 zone cassette alternatives
• best della mini splits under 2500
• della 18k btu 2 zone review
• gasland 18k btu propane heater review