Best Split Unit Air Conditioner: A Complete 2025 Buying Guide
In the age of smart energy usage and tailored comfort, choosing the best split unit air conditioner for your space can dramatically improve both your quality of life and energy bills. Split unit air conditioners—also known as ductless systems—are quiet, efficient, and ideal for homes, offices, and apartments that lack ductwork.
Whether you’re upgrading your current HVAC system or cooling a new room, this guide will walk you through how split units work, why they’re beneficial, what features to look for, and which models are the best-rated in 2025.
What Is a Split Unit Air Conditioner?
A split unit air conditioner is a two-part air conditioning system that includes:
- Indoor Unit: Mounted inside the space you want to cool or heat. It distributes conditioned air using a blower fan.
- Outdoor Unit: Contains the compressor and condenser. It expels heat collected from the indoor air to the outside.
The two units are connected via refrigerant lines, a power cable, and a drain hose through a small hole in the wall. This setup makes them more flexible and less invasive than central HVAC systems.
Benefits of Split Unit Air Conditioners
✔ High Energy Efficiency
Split units avoid the energy loss that occurs in ducted systems. Many also use inverter compressors, which adjust their speed based on demand and save more power over time.
✔ Quiet Operation
Since the noisy compressor is outside, the indoor environment stays remarkably quiet—ideal for bedrooms, home offices, and libraries.
✔ Easy Installation
Installation is quicker and less disruptive than ducted systems. No need for major home renovations or ductwork construction.
✔ Zoned Cooling
Multi-split systems allow for multiple indoor units, giving you independent control of temperature in each room.
✔ Year-Round Comfort
Many models also include heat pumps, allowing them to provide both cooling in summer and heating in winter.
How to Choose the Best Split Unit Air Conditioner
1. Room Size and BTU Capacity
Choose a unit with the correct BTU (British Thermal Unit) rating for your room size to ensure efficient cooling.
| Room Size (sq ft) | Recommended BTU |
|---|---|
| 100–300 | 9,000 |
| 300–500 | 12,000 |
| 500–800 | 18,000 |
| 800–1,200 | 24,000 |
2. SEER & HSPF Ratings
- SEER (Seasonal Energy Efficiency Ratio): Indicates cooling efficiency. The higher, the better—look for SEER 18+
- HSPF (Heating Seasonal Performance Factor): For heating efficiency. A score of 9+ is considered excellent.
3. Smart Features
Look for models with Wi-Fi, app control, scheduling, sleep mode, and voice assistant integration for added convenience.
4. Installation Method
- DIY-Friendly: Brands like MRCOOL offer pre-charged line sets for easier installation.
- Professional Install: Ideal for multi-zone or high-end systems that require vacuuming and pressure testing.
5. Noise Level
Choose units that run under 25 decibels indoors for whisper-quiet operation—ideal for night-time use.
Top 5 Best Split Unit Air Conditioners in 2025
1. Mitsubishi Electric MUZ-FS Series
- SEER: Up to 33.1
- BTU: 6,000–36,000
- Noise Level: 19 dB
- Ideal For: Premium performance in all seasons
Widely considered the best in class, Mitsubishi’s split units offer extreme energy efficiency, superior filtration, and ultra-quiet indoor operation. Its Hyper-Heating INVERTER® technology ensures consistent warmth even at -13°F.
2. Daikin 17 Series
- SEER: 17
- BTU: 9,000–24,000
- Noise Level: 22 dB
- Ideal For: Value buyers wanting a reliable, quiet solution
Daikin is known for durability and innovation. The 17 Series is compact, efficient, and equipped with advanced filtration. It’s a great fit for single-room applications.
3. Gree Livo+ Series
- SEER: Up to 23
- BTU: 9,000–24,000
- Noise Level: 23 dB
- Ideal For: Budget-conscious users who still want performance
Gree Livo+ is one of the most affordable high-efficiency systems. With features like auto-restart, intelligent defrost, and sleep mode, it delivers excellent value for the price.
4. LG Art Cool Mirror
- SEER: Up to 21.5
- BTU: 9,000–18,000
- Noise Level: 23 dB
- Ideal For: Design-conscious homes with smart integrations
Combining function with style, the LG Art Cool Mirror blends into modern interiors. Its ThinQ app offers remote operation and scheduling, and it works with Alexa and Google Assistant.
5. MRCOOL DIY 4th Gen
- SEER: Up to 22
- BTU: 12,000–36,000
- Noise Level: 24 dB
- Ideal For: Homeowners who want to install it themselves
MRCOOL DIY is pre-charged and designed for easy setup. It includes Wi-Fi, app control, and smart home compatibility. It’s the go-to for anyone wanting to skip installer fees without sacrificing quality.
Cost Breakdown of Split Unit ACs
| Brand | Unit Cost (USD) | Installation | Total Estimate |
|---|---|---|---|
| MRCOOL DIY | $1,200 – $2,500 | DIY | $1,200 – $2,500 |
| Gree Livo+ | $1,000 – $1,800 | $800 – $1,200 | $1,800 – $3,000 |
| Mitsubishi MUZ-FS | $2,800 – $5,000 | $1,200 – $2,000 | $4,000 – $7,000 |
Maintenance Tips
- Clean or replace filters every 4–6 weeks
- Keep the outdoor unit clear of leaves, snow, and debris
- Flush condensate lines annually
- Schedule professional check-ups once per year
Conclusion
The best split unit air conditioner offers unmatched efficiency, comfort, and quiet performance. Whether you’re cooling one room or multiple zones, split systems are the smart choice for modern living—delivering personalized climate control without bulky ducts or noisy machinery.
By understanding your needs and exploring top-rated brands like Mitsubishi, Daikin, LG, MRCOOL, and Gree, you can confidently invest in a system that keeps you comfortable all year—while saving energy and money along the way.