Della 12,000 BTU Smart Window AC Review: Alexa, App, 550 Sq Ft
A 12,000 BTU Wi-Fi window air conditioner for rooms up to 550 sq. ft. with Della+ app and Alexa control, a remote, Auto, Cool, Fan and Dry modes, eco and sleep modes and a listed CEER of 10.9.
By Daniel Brooks
Updated October 8, 2026
The Della 12,000 BTU Smart Window AC is a Wi-Fi unit for large rooms up to 550 square feet that runs on standard 115V power. It works with the Della+ app and Alexa, and the product title also highlights a GEO location feature. Among smart conventional window air conditioners, it offers a broad feature set with a stated CEER.
It suits a living room, a large bedroom, an office or an apartment. The main considerations are its weight and a 16 inch minimum window height. We evaluated it based on the manufacturer’s specifications.
Our Verdict
This Della is a well-equipped smart unit for larger rooms. Its strongest points are the Della+ app with Alexa voice control, a remote, an LED control panel, four modes (Auto, Cool, Fan and Dry), 3 fan speeds, sleep and eco modes, a 24-hour timer, a temperature range of 61°F to 88°F, a listed CEER of 10.9 and a UL listing.
The trade-offs are weight and noise. At 63.7 pounds, installation needs two people, and the listed noise level is 56 dB. The specification sheet lists an inverter, but the feature list does not mention one, so confirm this with Della if it matters to you. If you want smart cooling for a room up to 550 square feet on a standard outlet, it is worth considering.
Della 12000 BTU Smart Window Air Conditioner
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Key Specifications
| Feature | Specification |
|---|---|
| Brand | Della |
| Type | Smart window air conditioner |
| Cooling Capacity | 12,000 BTU |
| Room Size (listed) | Up to 550 sq. ft. |
| Efficiency | CEER 10.9 |
| Noise Level | As low as 56 dB |
| Voltage / Power | 115V, 60Hz, 991W, UL Listed |
| Window Fit | 26″ to 36″ wide, 16″ minimum height |
| Dimensions | 21.5″D x 19.76″W x 15.16″H |
| Weight | 63.7 pounds |
| Modes | Auto, Cool, Fan, Dry, plus Eco and Sleep |
| Fan Speeds | 3 |
| Temperature Range | 61°F to 88°F |
| Smart Controls | Della+ app, Alexa, remote, LED panel |
| Timer | 24-hour |
| Refrigerant | R-32 |
Cooling Capacity and Room Size
Della rates the unit at 12,000 BTU for rooms up to 550 square feet and suggests large living rooms, homes, offices and apartments. That covers most apartment living rooms and a large primary bedroom.
As always, the listed maximum is the upper limit. A room near 550 square feet with heavy sun or an open kitchen will push the unit harder. If your room is well under 450 square feet, a smaller unit may be a better match.
An oversized unit cools quickly and then shuts off before removing much moisture, which can leave a bedroom feeling cool but clammy. Dry mode helps on muggy days, but matching capacity to the room gives the best comfort.
ENERGY STAR publishes this general guide for sizing a room air conditioner by floor area:
| Room Size (sq ft) | Cooling Capacity (BTU/hr) |
|---|---|
| 100 to 150 | 5,000 |
| 150 to 250 | 6,000 |
| 250 to 300 | 7,000 |
| 300 to 350 | 8,000 |
| 350 to 400 | 9,000 |
| 400 to 450 | 10,000 |
| 450 to 550 | 12,000 |
| 550 to 700 | 14,000 |
| 700 to 1,000 | 18,000 |
Adjust for your room: reduce capacity by 10 percent for a heavily shaded room, increase it by 10 percent for a very sunny room, add 600 BTU for each regular occupant beyond two, and add 4,000 BTU if the unit cools a kitchen. Source: ENERGY STAR.
At its listed 12,000 BTU, it lines up with rooms of about 450 to 550 square feet, which matches Della’s coverage claim.
Installation and Fit
Della lists a fit for windows from 26 to 36 inches wide with a minimum height of 16 inches. Complete installation accessories are included, and Della says no major changes to the window frame are needed.
The cabinet measures 21.5 inches deep, 19.76 inches wide and 15.16 inches tall, and weighs 63.7 pounds. Plan on two people: one to hold the unit and one to lower the sash and fasten the hardware. Follow the manual and plug it into a standard 115V outlet.
Noise, Energy Use and Efficiency
Della lists sound levels as low as 56 dB. That is reasonable for a 12,000 BTU unit in a living room, though light sleepers should use sleep mode and the lowest fan speed in a bedroom.
The listed CEER of 10.9 is the standard rating for room air conditioners and is useful for comparison. The power draw is 991 watts. Eco mode, sleep mode and the 24-hour timer help reduce running time.
Controls and Smart Features
The redesigned Della+ app lets you control the unit anytime, anywhere, and it works with Alexa for voice commands. The app lets you adjust temperature, fan speed and mode from your phone, and the GEO location feature named in the title can help automate cooling around when you come and go.
The included remote and LED control panel cover all settings in the room. You get four modes (Auto, Cool, Fan and Dry), 3 fan speeds, sleep and eco modes, a 24-hour timer and a temperature range of 61°F to 88°F.
Voice control is handy in a living room where the remote is easy to misplace. A quick command to change the temperature or switch to eco mode works from anywhere in the room, and others in the household can use the app on their own phones.
Maintenance and Drainage
The title lists a reusable filter. Remove and rinse it regularly during the cooling season to keep airflow and efficiency steady.
Dry mode reduces humidity and, as Della notes, helps prevent mold growth in humid months. The listing does not describe condensate drainage, so check the manual for how water is handled.
Pros and Cons
| Pros | Cons |
|---|---|
| Della+ app and Alexa support | Heavy at 63.7 pounds |
| Remote and LED panel | Listed noise level of 56 dB |
| Auto, Cool, Fan and Dry modes | Needs a window at least 26″ wide and 16″ high |
| Listed CEER of 10.9 | Inverter status unclear in the listing |
| Eco, sleep and 24-hour timer |
Who Should Buy It
| Who Should Buy It? | Who Should Look Elsewhere? |
|---|---|
| Living rooms and large bedrooms up to 550 sq. ft. | Small bedrooms that need less capacity |
| Smart home users with Alexa | Light sleepers who need a quieter unit |
| Buyers who want app and remote control | Windows narrower than 26″ |
| Humid rooms that benefit from Dry mode | Anyone installing alone |
| Homes with a standard 115V outlet | Casement or sliding window owners |
Final Verdict
The Della 12000 BTU Smart Window Air Conditioner combines Della+ app and Alexa control, a remote, four modes, eco and sleep modes and a listed CEER of 10.9 for rooms up to 550 square feet. The compromises are a 63.7 pound weight, a listed 56 dB and a larger window requirement. You can check the current price and details for the Della 12000 BTU Smart Window Air Conditioner, or compare other WiFi window air conditioners.
Frequently Asked Questions
Does the Della 12000 BTU unit work with Alexa?
Yes. It works with Alexa voice control and the Della+ app, and a remote is included.
What window size does it fit?
Della lists windows from 26 to 36 inches wide with a minimum height of 16 inches.
Does it need a special outlet?
No. Della lists it as a 115V, 60Hz unit, so it uses a standard household outlet.
Does it dehumidify?
Yes. Dry mode reduces humidity levels in the room.
About the author
Daniel Brooks is a home cooling editor at WikiCooling, covering window, portable, through-the-wall and mini-split air conditioners, fans, and dehumidifiers. He researches cooling capacity, energy efficiency, noise levels, installation requirements, and buyer feedback to help homeowners choose the right unit for their room size, climate, and budget.