Della 5,000 BTU Mechanical Window AC Review: Simple, CEER 11.0
A 5,000 BTU mechanical window air conditioner for small rooms up to 150 sq. ft. with a listed CEER of 11.0, 51 to 55 dB noise, rotary switches, horizontal manual swing and a reusable filter.
By Daniel Brooks
Updated October 8, 2026
The Della 5,000 BTU Mechanical Window AC is a mechanically controlled small-room unit with a listed CEER of 11.0. Della rates it for rooms up to 150 square feet, such as a small bedroom or home office. Among basic conventional window air conditioners, it stands out for listing both its efficiency and a noise range.
It uses simple rotary switches rather than a digital panel or remote. The question is whether that simplicity suits you. We evaluated it based on the manufacturer’s specifications.
Our Verdict
This Della is a straightforward small-room unit. Its strongest points are the listed CEER of 11.0, a noise range of 51 to 55 dB, rotary switches for temperature and fan speed, a cooling range of 61°F to 88°F, horizontal manual swing, a reusable filter, a compact cabinet, a complete installation kit and a UL listing. It holds 4.0 stars from 465 ratings.
The trade-offs are control and fit. There is no remote, timer or eco mode, and the unit needs a window opening at least 14.5 inches high. If you want a simple, efficient unit for a room up to 150 square feet, it is worth considering.
Della 5,000 BTU Window Air Conditioner
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Key Specifications
| Feature | Specification |
|---|---|
| Brand | Della |
| Type | Window air conditioner, mechanical controls |
| Cooling Capacity | 5,000 BTU |
| Room Size (listed) | Up to 150 sq. ft. |
| Efficiency | CEER 11.0, 341 kWh per year |
| Noise Level | 51 to 55 dB |
| Voltage / Power | 115V, 60Hz, 460W, UL Listed |
| Window Fit | 23″ to 34″ wide, 14.5″ minimum height |
| Dimensions | 13.66″D x 15.98″W x 12″H |
| Weight | 36.4 pounds |
| Controls | Rotary switches for temperature and fan |
| Temperature Range | 61°F to 88°F |
| Fan | 2 fan-only speeds |
| Airflow | Horizontal manual swing |
| Filter | Reusable |
| Compressor | No inverter |
| Refrigerant | R-32 |
| Warranty | 1 year |
Cooling Capacity and Room Size
Della rates the unit at 5,000 BTU for rooms up to 150 square feet and suggests living rooms and home offices. In practice, a small bedroom, study or home office is the best match, since most living rooms are larger than 150 square feet.
At this size, there is little spare capacity. A room right at 150 square feet with strong sun or several people will push the unit hard. For a shaded small room, it is a good fit.
It also works well in rooms that are used only part of the time, such as a guest room or a craft room. Simple rotary controls mean anyone can switch it on without instructions, and there is no display or remote to lose.
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 5,000 BTU, it lines up with rooms of about 100 to 150 square feet, which matches Della’s coverage claim.
Installation and Fit
Della lists a fit for windows from 23 to 34 inches wide with a minimum height of 14.5 inches. Complete installation accessories are included, and Della says no major changes to the window frame are needed.
The compact cabinet measures 13.66 inches deep, 15.98 inches wide and 12 inches tall, and weighs 36.4 pounds. One person can lift it, but a helper makes installation safer. Follow the manual and plug it into a standard 115V outlet.
The 14.5 inch minimum height is a little more than some small units need, so measure your window opening with the sash fully raised.
Noise, Energy Use and Efficiency
Della lists a noise range of 51 to 55 dB and describes the unit as quieter than a household refrigerator. That is reasonable for a small bedroom, especially on the lower fan setting.
The listed CEER of 11.0 is a useful figure, since CEER is the standard efficiency rating for room air conditioners. Annual energy use is listed at 341 kWh and the power draw at 460 watts. There is no eco mode, and the compressor has no inverter.
Controls and Smart Features
Two rotary switches adjust the temperature and fan speed. The cooling range runs from 61°F to 88°F, and there are 2 fan-only speeds for air circulation without cooling. Horizontal manual swing lets you direct airflow by hand.
There is no remote, no timer and no Wi-Fi. In a small room the unit is usually within reach, so this matters less than in a larger space, and simple rotary controls are easy for anyone to use.
The horizontal manual swing lets you set the airflow direction once and leave it, aiming air away from a bed or desk if you prefer indirect cooling.
Maintenance and Drainage
The reusable filter is easy to remove and rinse. Clean it every few weeks during the cooling season to keep airflow and efficiency steady.
The listing does not describe condensate drainage. Check the manual for how water is handled and for steps to remove and store the unit at the end of the season.
Pros and Cons
| Pros | Cons |
|---|---|
| Listed CEER of 11.0 | No remote control or timer |
| Noise range of 51 to 55 dB | No eco or sleep mode |
| Simple rotary controls | Needs a window at least 14.5″ high |
| Compact cabinet at 36.4 pounds | No inverter compressor |
| Reusable filter and full install kit | Only sized for rooms up to 150 sq. ft. |
Who Should Buy It
| Who Should Buy It? | Who Should Look Elsewhere? |
|---|---|
| Small bedrooms and offices up to 150 sq. ft. | Rooms larger than 150 sq. ft. |
| Buyers who prefer simple controls | Anyone who wants a remote or timer |
| Buyers who value a listed CEER | Smart home users wanting app control |
| Renters who want a light, simple unit | Windows under 14.5″ of opening height |
| Occasional-use rooms | Casement or sliding window owners |
Final Verdict
The Della 5,000 BTU Window Air Conditioner is a simple, efficient unit for small rooms, with a listed CEER of 11.0, a noise range of 51 to 55 dB, rotary controls and a compact cabinet. It suits a small bedroom or office up to 150 square feet. The compromises are no remote, timer or eco mode and a 14.5 inch minimum window height. You can check the current price and details for the Della 5,000 BTU Window Air Conditioner, or compare other window air conditioners with reusable filters.
Frequently Asked Questions
What size room is the Della 5,000 BTU unit for?
Della rates it for rooms up to 150 square feet. On the ENERGY STAR chart, 5,000 BTU fits rooms of about 100 to 150 square feet.
Does it have a remote?
No. It uses rotary switches to adjust temperature and fan speed.
How efficient is it?
Della lists a CEER of 11.0 and annual energy use of 341 kWh.
What window size does it fit?
Della lists windows from 23 to 34 inches wide with a minimum height of 14.5 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.