When choosing a mini split 18000 BTU system for backup heating, I focus on two standout options. The Rellytech Mini Split AC/Heating System shines with its affordable energy efficiency and versatile modes, making it suitable for most home environments. Meanwhile, the EXNOS 18000BTU Mini-Split offers superior inverter technology, Wi-Fi control, and generator compatibility, catering to those who need reliable backup power during outages. Both models have their strengths and tradeoffs, especially around installation complexity, energy savings, and remote control features.
Key Takeaways
- The Rellytech system provides a balanced mix of affordability and performance, ideal for typical residential use.
- The EXNOS model excels in energy efficiency and backup power capabilities, suited for remote or emergency backup needs.
- Installation complexity varies significantly, with the EXNOS requiring professional setup due to its advanced features.
- Wi-Fi and remote control features are more comprehensive in the EXNOS system, offering better convenience.
- Both options cover similar space sizes (up to 1250 sq. ft.), but their energy efficiency and backup features differ markedly.
| Rellytech Mini Split Ac/Heating System, 18000 BTU Mini Split Air Conditioner Inverter with Heat Pump, 230V 19 SEER2 Energy Efficient Ac Units Up to 1250 Sq.Ft, 24H Timer, Installation Kit |  | Best Overall Balance of Cost, Efficiency, and Features | Cooling Capacity: 18000 BTU | Heating Capacity: 18400 BTU | SEER2: 19 | VIEW LATEST PRICE | See Our Full Breakdown |
| 18000BTU Mini-Split Air Conditioner – 21 SEER2 208/230V WiFi-Enabled Inverter Ductless System AC, Pre-Charged Condenser, Cools & Heats up to 1250 Sq Ft, Installation Kits |  | Best for Backup Power and Smart Control | Cooling Capacity: 18000 BTU | Heating Capacity: 19000 BTU | SEER2: 21 | VIEW LATEST PRICE | See Our Full Breakdown |
More Details on Our Top Picks
Rellytech Mini Split Ac/Heating System, 18000 BTU Mini Split Air Conditioner Inverter with Heat Pump, 230V 19 SEER2 Energy Efficient Ac Units Up to 1250 Sq.Ft, 24H Timer, Installation Kit
The Rellytech system offers 18,000 BTU cooling and 18,400 BTU heating, making it suitable for spaces up to 1,250 sq. ft. Its 19 SEER2 rating ensures lower energy costs, and the four operating modes give flexibility for year-round comfort. It stands out for its quiet operation—only 42dB—and smart eco mode, which balances performance and energy savings. However, it requires professional installation and 230V power, which could be a hurdle for DIY enthusiasts. Compared with high-tech Wi-Fi models, it’s more straightforward but less feature-rich in remote controls. Its main tradeoff is slightly lower efficiency than premium inverter systems, but it still offers good value for typical backup heating needs.
Pros:- High energy efficiency (19 SEER2)
- Quiet operation at 42dB
- Versatile modes including dry and eco
- Good coverage up to 1250 sq. ft.
Cons:- Requires professional HVAC installation
- Limited remote control features
- 230V power requirement
Best for: Homeowners seeking reliable, energy-efficient backup heat with straightforward installation.
Not ideal for: Users wanting advanced remote controls or Wi-Fi integration without professional setup.
- Cooling Capacity:18000 BTU
- Heating Capacity:18400 BTU
- SEER2:19
- HSPF2:8.5
- Coverage Area:Up to 1250 sq. ft.
- Power Supply:230V
Bottom line: A solid, budget-friendly choice for those who want dependable backup heating with straightforward controls.
18000BTU Mini-Split Air Conditioner – 21 SEER2 208/230V WiFi-Enabled Inverter Ductless System AC, Pre-Charged Condenser, Cools & Heats up to 1250 Sq Ft, Installation Kits
This EXNOS model delivers 18,000 BTU cooling and 19,000 BTU heating with a remarkable 21 SEER2 efficiency, making it one of the most energy-efficient options available. Its inverter technology automatically adjusts operation, providing stable comfort while reducing energy use. The built-in Wi-Fi allows remote control via smartphone, and its compatibility with external generators makes it an excellent choice for backup power during outages. The system is designed for professional installation due to its advanced features and electrical requirements, but it offers the peace of mind of reliable, stable performance in extreme weather conditions from -13°F to 122°F. Its main drawback is higher initial cost and the need for professional setup, but it compensates with superior backup capabilities and remote convenience.
Pros:- Exceptional 21 SEER2 efficiency
- Wi-Fi control and remote operation
- Generator-compatible for backup power
- Reliable in extreme temperatures (-13°F to 122°F)
Cons:- Requires professional installation
- Higher initial cost
- Complex setup for non-experts
Best for: Homeowners needing a high-efficiency, backup power-ready system with remote control features.
Not ideal for: DIYers seeking simple, plug-and-play solutions or those on a tight budget.
- Cooling Capacity:18000 BTU
- Heating Capacity:19000 BTU
- SEER2:21
- HSPF2:N/A
- Coverage Area:Up to 1250 sq. ft.
- Power Supply:208/230V
Bottom line: The ideal choice for tech-savvy users wanting reliable, energy-efficient backup heating with remote management.
How We Picked
My selection process involved evaluating each mini split based on cooling and heating capacity, energy efficiency ratings, backup power compatibility, remote control options, and installation requirements. I prioritized models offering reliable performance in cold weather, ease of integration into backup power systems, and user-friendly controls. Tradeoffs such as higher upfront cost versus long-term savings and installation complexity versus convenience played a key role in creating a balanced lineup.
Factors to Consider When Choosing Best Mini Split 18000 BTU For Backup Heating
Choosing the right mini split 18000 BTU system for backup heating involves balancing efficiency, installation complexity, and backup power features. Here, I highlight key considerations to help you decide which model best fits your needs.Energy Efficiency and Performance
Energy efficiency directly impacts your long-term costs. Higher SEER2 ratings mean less electricity used, which is especially important for backup systems that might run frequently during outages. Both models reviewed deliver sufficient capacity for typical homes, but the EXNOS stands out with its 21 SEER2 rating, making it more cost-effective over time.
Backup Power Compatibility
If reliable backup during power outages is your main priority, the EXNOS system’s generator compatibility makes it a clear winner. It can connect to external power sources, maintaining heating and cooling even when grid power fails. The Rellytech, while efficient, does not include this feature and relies solely on standard electrical supply.
Ease of Installation and Use
Both systems require professional installation, but the Rellytech is somewhat more straightforward, with fewer advanced features. The EXNOS system’s smart Wi-Fi control and compatibility with generators add layers of complexity, making it more suitable for those comfortable with technical setup or with professional help.
Frequently Asked Questions
Can these mini splits be used as a primary heat source?
While both models provide reliable heating, they are primarily designed as supplemental or backup systems. Their capacity is suitable for heating smaller spaces or supplementing existing heating systems, but they may not be ideal as the sole heat source for larger, colder homes.
What is the advantage of the inverter technology in these systems?
Inverter technology allows the compressor to adjust its speed based on the current heating or cooling demand, which reduces energy waste and lowers utility bills. It also provides more stable indoor temperatures and quieter operation, especially noticeable in the EXNOS model, which boasts 21 SEER2 efficiency.
Do I need professional installation for these units?
Yes, both units require professional HVAC installation due to their electrical and refrigerant system complexities. Proper setup ensures optimal performance, safety, and compliance with local codes, especially for the generator-compatible EXNOS system.
How does backup power compatibility influence my choice?
If backup power during outages is a priority, the EXNOS mini split offers a significant advantage by supporting external generators. This feature can keep your heating and cooling running during emergencies, making it a more reliable choice in areas prone to power interruptions.
Are these systems suitable for outdoor installation?
Yes, both models are designed to be installed outdoors, with weather-resistant components. They are suitable for garages, basements, or outdoor wall mounting, provided they are installed according to manufacturer guidelines to ensure durability and performance.
Conclusion
For homeowners seeking a straightforward, energy-efficient backup heating solution without extensive smart features, the Rellytech Mini Split offers excellent value and reliable performance. Conversely, those who prioritize remote control, higher efficiency, and backup power capabilities should consider the EXNOS 18000BTU Mini-Split, especially if professional installation and higher upfront costs are acceptable.
