Keystone 12,000 BTU Window Air Conditioner with vs MilleLoom Smart 6000 BTU Window Air Conditioner with WiFi,
Updated July 2026 — Keystone 12,000 BTU Window Air Conditioner with leads on price and room size.
The Keystone 12 is a powerful option for larger spaces with heating capabilities, while the Smart 6000 is a budget-friendly choice for smaller areas with smart features.
Why Keystone 12,000 BTU Window Air Conditioner with is better
Cooling Capacity
12,000 BTU vs 6,000 BTU
Heating Feature
Includes supplemental heating
Room Size
Cools up to 550 sq ft vs 350 sq ft
Why MilleLoom Smart 6000 BTU Window Air Conditioner with WiFi, is better
Price
$170.99 vs $449.99
Smart Features
WiFi control via app
Noise Level
Quieter operation at 50 dB
Overall score
Specifications
| Spec | Keystone 12,000 BTU Window Air Conditioner with | MilleLoom Smart 6000 BTU Window Air Conditioner with WiFi, |
|---|---|---|
| Brand | Keystone | MilleLoom |
| Model | 12,000 BTU | 6,000 BTU |
| WiFi | No | Yes |
| Heating | Yes | No |
| Installation | Kit included | Easy install kit |
Dimension comparison
Overview of Keystone 12 and Smart 6000 BTU Window Air Conditioners
The Keystone 12,000 BTU Window Air Conditioner is designed for larger spaces, while the Smart 6000 BTU Window Air Conditioner targets smaller areas. The Keystone unit offers a robust cooling and heating option for rooms up to 550 square feet, making it ideal for living rooms or medium-sized apartments. In contrast, the Smart unit is suitable for spaces up to 350 square feet, which makes it perfect for bedrooms or smaller environments.
Pricing Comparison
The Keystone 12 is priced at $449.99, while the Smart 6000 is significantly cheaper at $170.99, making it about 62% less expensive. This steep price difference may make the Smart model more appealing for budget-conscious consumers or those needing an air conditioner for smaller areas. However, the higher cost of the Keystone unit reflects its greater capacity and added heating feature, which could justify the investment for larger spaces or year-round use.
Cooling and Heating Capability
The Keystone 12 boasts a cooling capacity of 12,000 BTU and includes an 11,000 BTU supplemental heating feature, making it a versatile choice for year-round comfort. This unit is suitable for medium-sized rooms up to 550 square feet, ensuring it can cool efficiently even in hot conditions. On the other hand, the Smart 6000 has a cooling capacity of 6,000 BTU, meant for rooms up to 350 square feet. While it provides adequate cooling for smaller spaces, it lacks any heating capability, potentially limiting its use during colder months.
Smart Features
The Smart 6000 is equipped with WiFi capabilities, allowing users to control the air conditioner via a smartphone app. This modern feature enables convenient operation from anywhere, making it easier to adjust settings on-the-go. The Keystone 12, however, includes a smart remote control which measures room temperature and sends signals to the unit every three minutes for accurate cooling. While both units offer some form of smart control, the Smart 6000’s WiFi functionality provides a higher level of convenience for tech-savvy users.
Energy Efficiency
Both air conditioners are designed to save energy, but they approach this goal differently. The Keystone 12 includes an 'Energy Saver' mode and 'Sleep' mode, which helps to lower energy usage and costs. This feature is particularly beneficial during extended use, contributing to overall savings on electric bills. Meanwhile, the Smart 6000 also incorporates energy-saving features, including a sleep mode that gradually increases temperature for better relaxation. However, given that the Keystone unit is designed for larger spaces, its efficiency may be more pronounced in practical use when cooling larger areas.
Noise Levels
The Smart 6000 is noted for its ultra-quiet operation, with sound levels as low as 50 dB, making it a suitable choice for bedrooms and quiet spaces. The Keystone 12 does not specify its noise levels, but larger units typically generate more noise during operation. For users who prioritize a peaceful environment, the Smart 6000’s quieter performance could be a critical factor in their decision-making process.
Installation and Maintenance
Both units come with installation kits that facilitate easy setup. The Smart 6000’s quick-snap bracket simplifies the installation process, allowing users to set it up without hassle, while the Keystone 12 also includes a window installation kit. Maintenance is straightforward for both models, but the Smart unit features a slide-out filter for easy cleaning, which enhances user convenience compared to traditional filter setups. The Keystone 12 does not provide specific details on filter maintenance, which could be a consideration for potential buyers.
Which should you buy?
Choosing between the Keystone 12 and Smart 6000 ultimately comes down to your specific needs and preferences. If you require a powerful unit capable of cooling and heating larger spaces, the Keystone 12 is the clear winner, albeit at a higher price point of $449.99. However, if you're looking for a budget-friendly option for smaller spaces, the Smart 6000, priced at $170.99 and boasting smart features, may be the better choice. Consider your room size, budget, and desired features to make the best decision for your comfort needs.

