The Windmill AC review

Windmill sells its window unit direct, and the main selling point is setup: the install kit comes pre-assembled, and Windmill offers a flat $99 professional installation through Taskrabbit. The 6K BTU Original is rated for rooms up to 250 sq ft and was $269 at our check, down from $339. The WhisperTech versions add a dual air intake that Windmill says cools faster and more efficiently; the 8K WhisperTech was $359 and the 12K WhisperTech $449, while the 8K Original and 10K WhisperTech were sold out. Windmill quotes up to 15.0 CEER for the line and noise from 42 dB. Air leaves at a 45 degree angle, the filter combines antimicrobial-protected mesh with activated carbon, and the side panels are double-insulated, which Windmill says is twice the Energy Star insulation requirement. Control comes from the app, voice assistants, a remote or soft on-unit buttons, with three cooling settings and three fan speeds. The 42 dB floor is louder than the inverter picks above it.

Who it is for

renters who want the easiest install

Price

From $269 for the 6K BTU Original on Windmill's store (list $339); 8K WhisperTech $359.

6K BTU Original $339 $269
Quoted from the vendor pricing page on November 14, 2026.

Key features

• Pre-assembled install kit with double-insulating side panels
• 6K BTU Original rated for rooms up to 250 sq ft
• WhisperTech models with dual air intake in 8K and 12K BTU
• Antimicrobial-protected mesh and activated carbon filter
• App and voice control, remote, and an auto-dimming LED display

Strengths and weaknesses

• Strength: Flat $99 Taskrabbit installation available nationwide
• Strength: Windmill rates the line up to 15.0 CEER
• Strength: Air exits at a 45 degree angle for wider airflow
• Weakness: 8K BTU Original and 10K BTU WhisperTech were sold out at our check
• Weakness: The 6K starting model covers only 250 sq ft
• Weakness: Noise starts at 42 dB, higher than the inverter units from Midea and GE

Key facts

• Sizes: 6K Original, 8K Original, 8K, 10K and 12K WhisperTech
• Room size (6K): Up to 250 sq ft
• Efficiency: Up to 15.0 CEER
• Noise: Starts at 42 dB
• Prices at our check: $269 (6K), $359 (8K WhisperTech), $449 (12K WhisperTech)

Where it ranks

The Windmill AC is No. 3 in our Best Window Air Conditioners verdict.