Antarctic Star 12,000 BTU U-Shaped Window AC Review: 41 dB
A 12,000 BTU U-shaped window air conditioner listed at 41 dB, with a Mytemp sensor, dehumidifier function and 24-hour timer. A fit for larger rooms where simple controls are enough.
By Daniel Brooks
Updated October 11, 2026
The Antarctic Star 12,000 BTU U-Shaped Window AC is a large-capacity window unit with a U-shaped body that keeps the window usable and your view clear. It is one of the longer-established U-shaped window air conditioners, with a conventional compressor, a Mytemp temperature sensor and a dehumidifier function.
It has 3.7 stars from 92 ratings. The main questions are which room size to trust, since the listing gives two different figures, and whether a non-inverter unit at 41 dB suits your space. We evaluated it based on the manufacturer’s specifications.
Our Verdict
The Antarctic Star is a straightforward pick for a larger room when you want 12,000 BTU, a dehumidifier function and simple controls. It is listed at 41 dB, includes foam sealers and a mounting block, and adds a Mytemp sensor and a 24-hour timer.
The trade-offs are a conventional compressor rather than an inverter, an efficiency figure of 6.1 that is low for its class, and no app control. Its room size claim varies between 400 and 550 square feet. If you want a basic, capable unit with the open-window advantage, it covers the essentials.
Prime Antarctic Star 12,000 BTU U-Shaped Window Air
As an Amazon Associate we earn from qualifying purchases. Product prices and availability are accurate as of the date/time indicated.
Key Specifications
| Feature | Specification |
|---|---|
| Brand | Antarctic Star |
| Type | U-shaped window air conditioner |
| Cooling Capacity | 12,000 BTU |
| Room Size (listed) | Up to 400 square feet (features), 550 sq. ft. (title) |
| Compressor | No inverter (listed in specifications) |
| Efficiency | 6.1 (listed as SEER) |
| Noise Level | 41 dB |
| Voltage | 115 volts |
| Window Fit | 24″ to 48″ wide, 24″ to 36″ opening height |
| Dimensions | 28.94″D x 18.7″W x 14.88″H |
| Weight | 66.8 pounds |
| Modes | Cooling, fan, dehumidifier, energy saving |
| Controls | Digital display, remote, Mytemp sensor, 24-hour timer |
| Refrigerant | R-32 |
| Included | Remote, foam sealer, top foam sealer, mounting block |
| Warranty | 1 year manufacturer |
Cooling Capacity and Room Size
Antarctic Star rates the unit at 12,000 BTU. The title says it cools up to 550 square feet, but the feature text says up to 400 square feet for a living room, bedroom, dorm or office. That is a wide gap, so treat the smaller figure as the safer guide.
It uses R32 refrigerant, and its dehumidifier function helps on muggy days when the air feels damp more than hot.
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 on the ENERGY STAR chart. The maker’s own feature text points lower, at 400 square feet, so a room between 400 and 550 square feet is the realistic target.
Good fits include a living room, a large primary bedroom or an open office. If the room gets strong afternoon sun or regularly holds more than two people, ENERGY STAR suggests adding capacity, which pushes this unit toward the lower end of that range.
Installation and Fit
The specifications give a window width of 24 to 48 inches and an opening height between 24 and 36 inches. That height requirement is taller than many U-shaped units need, so measure the open sash before ordering.
The box includes a foam sealer, a top foam sealer and a mounting block for a sealed fit. The listing describes the unit as easy to install and lightweight enough to move between windows, but at 66.8 pounds it is still a two-person job. It runs on 115 volts; check the manual for the outlet and circuit it needs.
Noise, Energy Use and Efficiency
The specifications list 41 dB, which is reasonable for a 12,000 BTU unit, helped by the U-shaped body that keeps the compressor outside. It does not have an inverter, so the compressor cycles on and off rather than slowing down.
The efficiency figure is 6.1, labeled as SEER, and the specifications list 1725 watts. An energy saving mode is included, and the Mytemp sensor is meant to hold the set temperature while using less energy. The listing does not mention ENERGY STAR certification.
Controls and Smart Features
The unit has a digital display with LED lights that are easy to read at night, and a remote for adjusting the temperature from your seat. The 24-hour timer handles scheduling.
The Mytemp sensor is the most useful control feature. It maintains the set temperature based on its own reading, which helps the unit hold steady comfort. There is no Wi-Fi, app or voice control.
The six functions cover cooling, fan and dehumidifier operation along with an energy saving mode, which is enough for most rooms that do not need smart home integration.
Use the timer to switch the unit off after you fall asleep or to start it before you get home. Because the unit cycles its compressor rather than slowing it down, a timer and the energy saving mode are the main tools for keeping running costs in check.
Maintenance and Drainage
The listing does not describe the filter or condensate drainage. Check the manual for how to remove and clean the filter, and plan to clean it regularly during heavy use.
Keep the foam sealers and mounting block with the unit when you take it down, since a good seal matters for both cooling and noise. Follow the manual for seasonal storage.
Before reinstalling it next season, check the foam for compression or tears and replace it if it no longer fills the gaps. Leaks around a U-shaped unit let in both warm air and outdoor noise.
Pros and Cons
| Pros | Cons |
|---|---|
| 12,000 BTU with a dehumidifier function | No inverter, cycles on and off |
| Listed at 41 dB | Efficiency figure of 6.1 is low |
| Mytemp sensor and 24-hour timer | Room size claims range from 400 to 550 sq. ft. |
| Foam sealers and mounting block included | Needs a 24 inch opening height |
| Window stays usable with the unit installed | No app or voice control |
Who Should Buy It
| Who Should Buy It? | Who Should Look Elsewhere? |
|---|---|
| Larger rooms between 400 and 550 sq. ft. | Buyers focused on energy efficiency |
| Buyers who want simple remote control | Smart home users who want app control |
| Damp rooms that need a dehumidifier mode | Windows that open less than 24 inches |
| Windows 24 to 48 inches wide | Anyone needing heating |
Final Verdict
The Antarctic Star 12,000 BTU U-Shaped Window AC gives larger rooms 12,000 BTU of cooling, a dehumidifier function, a Mytemp sensor and a 24-hour timer, with sealing hardware in the box and a listed 41 dB. It suits a buyer who wants a capable, simple unit with the open-window benefit. The compromise is a conventional compressor, a low listed efficiency figure and room size claims that do not agree. You can check the current price and details for the Antarctic Star 12,000 BTU U-Shaped Window Air Conditioner.
Frequently Asked Questions
What size room does the Antarctic Star 12,000 BTU cool?
The title says up to 550 square feet, but the feature text says up to 400 square feet. Plan for a room between those figures, toward the lower end if it is sunny.
Does it have an inverter?
No. The specifications list no inverter, so the compressor cycles on and off.
What comes in the box?
The listing includes a remote control, a foam sealer, a top foam sealer and a mounting block.
What windows does it fit?
The specifications give a width of 24 to 48 inches and an opening height between 24 and 36 inches.
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.