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This 20 SEER2 vs 17 SEER2 mini split air conditioner comparison looks at two 12,000 BTU units. Both cover 750 square feet and provide year-round cooling and heating. The main difference lies in efficiency and power requirements. The Rellytech model offers 20 SEER2 efficiency and runs on 115V. The COSTWAY unit provides 17 SEER2 efficiency and requires 230V power. You need to check your electrical setup before choosing.
SEER Rating
20 SEER2
17 SEER2
Voltage
115V
230V
Control Method
Wi-Fi, App, Remote
Remote
Heating HSPF2
not listed
8.5
Choose the first if
- You have a 115V outlet and want higher cooling efficiency.
- You prefer smart Wi-Fi control via a smartphone app.
- You need a unit with an included remote and digital display.
Choose the second if
- You have a 230V circuit available for installation.
- You want explicit heating efficiency data listed as 8.5 HSPF2.
- You prioritize a lower indoor noise level of 23 dB.
Verdict
Choose the Rellytech if you need 115V compatibility and smart app features. Pick the COSTWAY if your home has 230V power and you value quiet operation. Both units effectively cool and heat 750 square feet.
20 SEER2 vs 17 SEER2 Mini Split Specs
SEER Rating
Edge: Rellytech 12000 BTU 20 SEER2 Mini Split
The Rellytech model leads with a 20 SEER2 rating, while the COSTWAY unit offers 17 SEER2. Higher SEER2 numbers indicate better energy efficiency during cooling. The Rellytech specifications state that its 20 SEER2 rating is 30% more energy-efficient than standard 17 SEER2 models. This means the Rellytech unit consumes less electricity to produce the same amount of cooling power. For buyers focused on lowering long-term energy usage, the higher rating provides a clear advantage in operational efficiency. The COSTWAY unit remains efficient but trails in this specific metric.
Voltage Requirement
Edge: Rellytech 12000 BTU 20 SEER2 Mini Split
Power requirements differ significantly between these two units. The Rellytech mini split operates on 115V, which is a standard household outlet voltage. In contrast, the COSTWAY model requires 230V, a higher voltage typically found in dedicated circuits. This distinction affects installation complexity and compatibility with your existing electrical setup. If you have a standard 115V outlet available, the Rellytech unit is easier to connect. The COSTWAY unit may require a licensed electrician to install a new 230V circuit, adding to the initial setup requirements.
Control Method
Edge: Rellytech 12000 BTU 20 SEER2 Mini Split
Smart connectivity is a key differentiator for remote management. The Rellytech system includes built-in Wi-Fi, allowing control via a smartphone app or voice commands. It also comes with a remote featuring a digital display for direct operation. The COSTWAY unit relies on a handy remote control with an effective distance of 26 feet. While the COSTWAY remote allows adjustment of modes, speeds, and timers, it lacks the mentioned Wi-Fi app integration. If you prefer managing your climate from anywhere using your phone, the Rellytech option provides that capability.
Coverage Area
Edge: Tie
Both units are designed to condition the same amount of space. The Rellytech specifications indicate it is effective for spaces up to 750 square feet. Similarly, the COSTWAY model covers up to 750 square feet. Both provide 12,000 BTU of cooling capacity, which aligns with this coverage recommendation. Whether you are using the unit in a bedroom, living room, or garage, both products offer the same spatial reach. Neither product holds an advantage in terms of the size of the room they can effectively cool or heat.
Operating Modes
Edge: Tie
Both mini splits offer comprehensive climate control options. The Rellytech integrates cooling, heating, dry, and fan-only modes. It also features auto-defrost, a 24-hour timer, TURBO mode, iFEEL mode, sleep mode, silent mode, and eco mode. The COSTWAY unit provides seven modes: cool, heat, dry, fan, auto, sleep, and ECO, along with five fan speeds. Both include sleep modes and timers for energy saving. While the specific mode names differ slightly, both units provide the essential functions needed for year-round comfort and precise temperature adjustment.
Build and Dimensions
Edge: Tie
Physical specifications vary slightly between the two indoor units. The Rellytech unit measures 31.9 inches in width, 8.7 inches in height, and 11.4 inches in length. The COSTWAY unit is slightly narrower at 31.2 inches wide, 7.91 inches high, and 11.5 inches long. Both are white. The Rellytech indoor unit weighs 75.3 pounds, while the COSTWAY indoor unit is listed at 17.6 pounds. These dimensions will affect how the unit fits on your wall. The height difference may influence visibility and airflow direction in smaller rooms.
Choose the Right Mini Split for You
Homeowners with 115V outlets needing high efficiency
Our pick: Rellytech 12000 BTU 20 SEER2 Mini Split
The Rellytech unit operates on a standard 115V circuit, making installation simpler for many homes. It delivers a 20 SEER2 rating, which the manufacturer states is 30% more efficient than standard 17 SEER2 models. This higher efficiency rating suggests lower energy consumption during cooling cycles compared to less efficient alternatives.
Users in extreme climates requiring robust heating
Our pick: Rellytech 12000 BTU 20 SEER2 Mini Split
This model specifies a working temperature range from -13°F to 122°F. The outdoor unit features chassis electrical heating to handle extreme weather. It uses R454B refrigerant, which ensures better indoor air quality. These specs indicate reliable performance in both freezing winters and hot summers without frequent defrost cycles.
Renters or rooms with 230V power available
Our pick: COSTWAY 12000 BTU Mini Split 17 SEER2
The COSTWAY unit requires a 230V power source, which is common in dedicated circuits. It offers 17 SEER2 cooling efficiency and 8.5 HSPF2 heating efficiency. The indoor unit runs at just 23 dB, providing ultra-quiet operation. This low noise level, combined with a sleep mode, makes it suitable for bedrooms or quiet spaces.
| # | Product | Best for | Price |
|---|---|---|---|
| 1 | Rellytech 12000 BTU 20 SEER2 Mini Split | medium rooms needing efficient smart climate control | |
| 2 | COSTWAY 12000 BTU Mini Split 17 SEER2 | medium rooms needing quiet, efficient cooling |
Rellytech 12000 BTU 20 SEER2 Mini Split
Best for: medium rooms needing efficient smart climate control
- SEER Rating
- 20 SEER2
- Cooling Capacity
- 12,000 BTU
- Coverage Area
- up to 750 sq ft
- SEER2 Rating
- 20
- Voltage
- 110V/115V
- Smart Compatibility
- Wi-Fi, voice commands, remote
This Rellytech mini split delivers 12,000 BTU of cooling and heating for spaces up to 750 square feet. It features a 20 SEER2 rating, making it 30% more energy-efficient than standard 17 SEER2 models. The unit operates on 115V power and includes Wi-Fi app control for remote management. It uses R454B refrigerant and functions in temperatures from -13°F to 122°F. This system suits you if you need efficient year-round climate control for a bedroom or garage.
- 20 SEER2 rating for high energy efficiency
- Wi-Fi and app control for remote operation
- Wide operating temperature range from -13°F to 122°F
- Includes 24-hour timer and multiple operating modes
- ETL and AHRI certified for reliable performance
- Lower SEER2 rating than the 21 SEER2 option available in the same product line
- Heavier indoor unit at 75.3 pounds compared to lighter variants
- Requires professional installation by a licensed HVAC technician
- You want a 12000 BTU unit with high energy efficiency
- You need Wi-Fi control for remote temperature scheduling
- You require a system that works in extreme cold or heat
- You prefer a 230V system for higher power capacity
- You want a unit with a higher 21 SEER2 efficiency rating
- You are looking for a budget-friendly 17 SEER2 model
Verdict: Rellytech 12000 BTU 20 SEER2 Mini Split is a solid choice for you if you prioritize energy efficiency and smart control in a 12000 BTU package. It fits well in medium-sized rooms where you want reliable heating and cooling without the premium cost of the highest SEER2 tier.
COSTWAY 12000 BTU Mini Split 17 SEER2
Best for: medium rooms needing quiet, efficient cooling
- SEER Rating
- 17 SEER2
- Cooling Capacity
- 12000 BTU
- Coverage Area
- 750 sq ft
- SEER2 Rating
- 17 SEER2
- Voltage
- 208-230V
- Smart Compatibility
- Remote control
The COSTWAY 12000 BTU Mini Split offers 17 SEER2 cooling efficiency and 8.5 HSPF2 heating. It covers up to 750 sq ft with 12000 BTU cooling and 12300 BTU heating. The unit operates at 23 dB and includes 7 modes plus 5 fan speeds. You get 4D airflow and a remote with 26 ft range. It fits well if you need quiet, efficient climate control for medium-sized rooms.
- 17 SEER2 cooling rating for energy efficiency
- Ultra-quiet 23 dB operation level
- 4D swing airflow for even distribution
- Covers up to 750 sq ft area
- 17 SEER2 is lower than the 20 SEER2 option on this list
- 12000 BTU capacity is less than larger 18000 or 24000 BTU variants
- You need efficient cooling for a room up to 750 sq ft
- You prioritize quiet operation with 23 dB noise levels
- You want 4D airflow for better room coverage
- You require the highest 20 SEER2 efficiency rating available
- You need to cool a space larger than 750 sq ft
- You prefer higher 18000 BTU or 24000 BTU capacity units
Verdict: COSTWAY 12000 BTU Mini Split AC suits you if you value quiet 23 dB performance and 4D airflow for medium rooms, though you miss out on the top 20 SEER2 efficiency.
Specifications side by side
| Spec | Rellytech 12000 BTU 20 SEER2 Mini Split | COSTWAY 12000 BTU Mini Split 17 SEER2 |
|---|---|---|
| Cooling Capacity | 12,000 BTU | 12000 BTU |
| Coverage Area | up to 750 sq ft | 750 sq ft |
| SEER2 Rating | 20 | 17 SEER2 |
| Voltage | 110V/115V | 208-230V |
| Smart Compatibility | Wi-Fi, voice commands, remote | Remote control |
| Operating Modes | cooling, heat pump, dry, fan-only, eco | Cool, heat, dry, fan, auto, sleep, ECO |
| Features | Inverter, Quiet Operation | Inverter |
| Control Method | Wi-Fi, Wi-Fi App Control, Wi-Fi App | – |
| Color | White | White |
| Operating Mode | Heater | Heater |
| SEER Rating | 20 SEER2 | 17 SEER2 |
| Dimensions | 8.66 × 31.9 × 11.4 inches | 11.5 × 31.2 × 7.91 inches |
| Weight | 75.3 pounds | 17.6 pounds |
| Size | 12000BTU,115V,20 SEER2-WiFi | 12000BTU, 208-230V, 17 SEER2 |
| Model | CE0-1 | 11090-CYFP |
Frequently asked questions
Is a 20 SEER2 mini split worth the upgrade over 17 SEER2?
Yes, if you prioritize energy efficiency. The Rellytech model offers a 20 SEER2 rating, which indicates better cooling efficiency than the COSTWAY unit’s 17 SEER2. This higher rating suggests lower energy consumption for the same cooling output, making it a practical choice for reducing long-term usage costs.
Do both units require a 230V outlet?
No. The Rellytech 12000 BTU unit operates on a standard 115V circuit. The COSTWAY 12000 BTU model requires a 230V connection. You should check your home’s electrical setup before purchase. The 115V option may simplify installation for many existing homes without needing new high-voltage wiring.
Can these mini splits heat a room?
Yes, both units provide heating. The Rellytech and COSTWAY models both list heating as an operating mode. They are designed for year-round climate control. You can use them for cooling in summer and heating in winter, provided your indoor space falls within their specified coverage area of 750 square feet.
Which model is quieter, 20 SEER2 or 17 SEER2?
The COSTWAY 17 SEER2 unit is noted for quiet 23 dB performance. The Rellytech 20 SEER2 model lists quiet operation as a feature but does not specify a decibel level in the provided data. If low noise is your primary concern, the COSTWAY specifications highlight its quiet operation explicitly.
Do I need Wi-Fi for these mini splits?
No, but it helps. The Rellytech model includes Wi-Fi and app control features. The COSTWAY specifications do not mention smart connectivity options. If you want to control your unit remotely via a phone app, the Rellytech model supports this. Otherwise, standard manual controls are sufficient for basic operation.
How much space does each indoor unit take up?
Both units are similar in size. The Rellytech measures 31.9 inches wide by 8.7 inches high. The COSTWAY model is 31.2 inches wide by 7.91 inches high. Both are designed to fit medium-sized rooms. You should ensure your wall space can accommodate a unit roughly 32 inches wide.
Is the Rellytech model heavier than the COSTWAY?
Yes. The Rellytech unit weighs 75.3 pounds. The COSTWAY model weighs 17.6 pounds. This significant weight difference may affect installation requirements. Heavier units often require more robust mounting hardware. You should follow the manufacturer’s mounting guidelines to ensure the wall can support the specific weight of your chosen model.