As Amazon Associates, we earn from qualifying purchases. This means we may receive a small commission at no extra cost to you if you click through and make a purchase.
As an Amazon Associate we earn from qualifying purchases. Links on this page are affiliate links.
You are comparing a 19 SEER2 vs 20 SEER2 mini split air conditioner from Rellytech and COSTWAY. Both units are inverter-driven heat pumps that provide cooling and heating. They share white finishes and ductless wall-mounted designs. The main difference lies in capacity and power requirements. The Rellytech model offers 18,000 BTUs on 230V power for larger spaces. The COSTWAY unit provides 12,000 BTUs on 115V power for smaller rooms.
Cooling Capacity
18,000 BTU
12,000 BTU
Voltage
230V
115V
Coverage Area
1,250 Sq. Ft.
750 Sq. Ft.
Operating Modes
4 Modes
5 Modes
Indoor Unit Weight
112 pounds
68 pounds
Choose the first if
- You need to cool a larger area up to 1,250 square feet
- You have a 230V electrical circuit available for installation
- You prefer a unit with a higher heating capacity of 18,400 BTU
Choose the second if
- You are cooling a smaller room up to 750 square feet
- You only have a standard 115V outlet for power
- You want extra features like iFEEL and turbo function
Verdict
Choose the Rellytech unit if you need more power for a larger space and have the necessary 230V wiring. Pick the COSTWAY model for smaller rooms where a standard 115V outlet is available. Both are efficient inverter systems, but their capacity and voltage requirements dictate their best use cases.
19 vs 20 SEER2 Mini Split Specs
Coverage Area
Edge: Rellytech 18000 BTU 230V Mini Split
The Rellytech unit covers up to 1,250 square feet, making it suitable for larger spaces like living rooms or open-concept areas. The COSTWAY model is rated for 750 square feet, which fits smaller bedrooms or offices. You should choose the Rellytech if your space exceeds 750 square feet. The COSTWAY is better for compact rooms where excessive cooling power is unnecessary. Both units use inverter technology to maintain steady temperatures, but the capacity difference dictates where each fits best in your home.
Voltage Requirements
Edge: COSTWAY 12000 BTU 115V Mini Split
Power compatibility is a major deciding factor for installation. The Rellytech requires a 230V circuit, which is standard for larger mini splits and often requires dedicated heavy-duty wiring. The COSTWAY operates on 115V, allowing it to plug into standard household outlets in many cases. If you already have 230V lines installed, the Rellytech is ready to go. For easier retrofitting into existing rooms with standard outlets, the COSTWAY offers a simpler electrical setup without needing major upgrades.
Operating Modes
Edge: COSTWAY 12000 BTU 115V Mini Split
Both units provide essential climate control, but the feature set differs slightly. The Rellytech offers four modes: cooling, heating, fan, and dry. It also includes a Smart Eco function to optimize energy use. The COSTWAY provides five modes, adding an auto mode to the mix. It also lists specific functions like sleep mode, iFEEL, and turbo. If you prefer more granular control over fan behavior and automated adjustments, the COSTWAY offers a slightly richer set of operational modes for daily use.
Control Method
Edge: COSTWAY 12000 BTU 115V Mini Split
User interface preferences vary between these two models. The COSTWAY features a remote control with a display screen that automatically turns off after ten seconds of inactivity to reduce light disturbance during sleep. It also includes a timer function ranging from 0.5 to 24 hours. The Rellytech specifications do not explicitly detail remote display features or timer specifics in the provided data. If quiet operation and visible feedback from your remote are priorities, the COSTWAY design addresses these needs more clearly.
Physical Dimensions
Edge: Tie
Installation space and aesthetics matter when mounting the indoor unit. The Rellytech indoor unit measures 39.6 inches in width and 9.5 inches in height, weighing 112 pounds. The COSTWAY unit is wider at 44.5 inches but shorter at 13 inches in height, weighing only 68 pounds. The Rellytech is more compact horizontally but heavier. The COSTWAY is lighter but takes up more horizontal wall space. You should measure your wall area to ensure the chosen unit fits comfortably without obstructing furniture or windows.
Which Mini Split Fits Your Space
Large room owners needing high capacity
Our pick: Rellytech 18000 BTU 230V Mini Split
The Rellytech unit covers 1,250 square feet. Its 18,000 BTU cooling capacity handles larger areas effectively. You get 18,400 BTU of heating power. The 19 SEER2 rating offers solid efficiency for bigger spaces. This model suits open layouts or larger bedrooms where coverage matters most.
Small space users wanting quiet operation
Our pick: COSTWAY 12000 BTU 115V Mini Split
The COSTWAY model covers 750 square feet. It fits smaller rooms like bedrooms or offices. You get a 20 SEER2 rating for higher efficiency. The unit features a self-cleaning function and auto-defrost. Quiet operation and a remote with a dimming display support peaceful sleep in compact areas.
Buyers with standard 115V electrical outlets
Our pick: COSTWAY 12000 BTU 115V Mini Split
The COSTWAY unit operates on 115V power. This matches standard household outlets, simplifying installation. You do not need a dedicated 230V circuit. The 12,000 BTU capacity is sufficient for smaller zones. This voltage requirement makes it a practical choice for existing electrical setups in smaller homes.
| # | Product | Best for | Price |
|---|---|---|---|
| 1 | Rellytech 18000 BTU 230V Mini Split | Medium rooms needing strong heating and 230V power | |
| 2 | COSTWAY 12000 BTU 115V Mini Split | medium rooms on standard 115V circuits |
Rellytech 18000 BTU 230V Mini Split
Best for: Medium rooms needing strong heating and 230V power
- SEER Rating
- 19 SEER2
- Cooling Capacity
- 18,000 BTU
- Coverage Area
- up to 1,250 sq. ft.
- SEER2 Rating
- 19
- Voltage
- 208-230V
- Operating Modes
- cooling, heating, fan, dry, ECO
This Rellytech unit delivers 18,000 BTU of cooling and 18,400 BTU of heating for spaces up to 1,250 square feet. It operates on 230V power with a 19 SEER2 rating and an HSPF2 of 8.5. The system includes four fan speeds, a 90-degree vertical swing, and an ECO mode for efficient temperature control. It suits homeowners needing reliable year-round climate management for medium-sized rooms or offices.
- 18,000 BTU cooling capacity covers up to 1,250 sq. ft.
- 19 SEER2 energy efficiency rating reduces electricity use.
- Includes ECO mode for optimized temperature control.
- Four fan speeds and 90-degree vertical swing for airflow customization.
- 19 SEER2 is lower than the 20 SEER2 option available from other brands.
- Weighs 112 pounds, making installation more physically demanding.
- You need strong heating output of 18,400 BTU.
- You prefer a 230V electrical connection.
- You want a unit with an ECO mode for energy savings.
- You require the highest 20 SEER2 efficiency rating.
- You are installing in a space smaller than 1,250 sq. ft.
- You prefer a lighter unit for easier mounting.
Verdict: Rellytech 18000 BTU 19 SEER2 Mini Split is a solid choice for users who prioritize high heating output and 230V compatibility over maximum efficiency ratings.
COSTWAY 12000 BTU 115V Mini Split
Best for: medium rooms on standard 115V circuits
- SEER Rating
- 20 SEER2
- Cooling Capacity
- 12000 BTU
- Coverage Area
- up to 750 Sq. Ft
- SEER2 Rating
- 20 SEER2
- Voltage
- 115V
- Smart Compatibility
- remote control
This COSTWAY unit offers 12,000 BTU cooling and heating with a 20 SEER2 rating on a standard 115V circuit. It covers up to 750 square feet using inverter technology to adjust power without frequent compressor cycling. The system includes five modes, four fan speeds, and remote control with a timer. It weighs 68 pounds and mounts to the wall. You get AHRI certification and a 5-year parts warranty.
- 20 SEER2 energy efficiency rating
- 12,000 BTU capacity for 750 sq ft
- Standard 115V electrical connection
- Inverter technology for stable operation
- 5-year parts and 8-year compressor warranty
- Lower SEER2 rating than the 19 SEER2 208-230V option on the list
- Smaller 12,000 BTU capacity compared to larger units
- Heavier 68-pound build for wall mounting
- You need a standard 115V outlet for installation
- You want to cool a room up to 750 square feet
- You prefer a unit with a 20 SEER2 efficiency rating
- You require a 208-230V high-voltage connection
- You need to cool a space larger than 750 square feet
- You want the highest SEER2 rating available on the list
Verdict: COSTWAY 12000 BTU 115V 20 SEER2 Mini Split fits homes with standard 115V circuits that need efficient cooling for medium-sized rooms up to 750 square feet.
Specifications side by side
| Spec | Rellytech 18000 BTU 230V Mini Split | COSTWAY 12000 BTU 115V Mini Split |
|---|---|---|
| Cooling Capacity | 18,000 BTU | 12000 BTU |
| Coverage Area | up to 1,250 sq. ft. | up to 750 Sq. Ft |
| SEER2 Rating | 19 | 20 SEER2 |
| Voltage | 208-230V | 115V |
| Smart Compatibility | – | remote control |
| Operating Modes | cooling, heating, fan, dry, ECO | auto, cool, dry, heat, fan |
| Features | Inverter | Inverter |
| Color | White | White |
| Operating Mode | – | Heater |
| SEER Rating | 19 SEER2 | 20 SEER2 |
| Mounting Type | – | Wall-Mounted |
| Dimensions | 9.02 × 40.4 × 12.6 inches | 9 × 44.5 × 13 inches |
| Weight | 112 pounds | 68 pounds |
| Size | 18000BTU,230V,19 SEER2 | 12000BTU, 115V, 20 SEER |
| Model | CE0-1 | 10153-CYJV |
Frequently asked questions
Does a higher SEER2 rating always mean better performance?
A higher SEER2 rating indicates greater energy efficiency, not necessarily superior cooling speed. The 20 SEER2 COSTWAY model uses less electricity per unit of cooling than the 19 SEER2 Rellytech unit. You should choose based on your local electricity rates and usage patterns rather than assuming higher numbers equal faster temperature changes.
Can I install a 230V mini split on a standard outlet?
No, a 230V unit requires a dedicated circuit and specific wiring. The Rellytech 18000 BTU model operates on 230V and will not work with standard 115V household outlets. You must verify your home’s electrical capacity before purchasing. The COSTWAY 12000 BTU model uses 115V, making it compatible with standard circuits.
What is the weight difference between these two units?
The Rellytech unit weighs 112 pounds, while the COSTWAY model weighs 68 pounds. This 44-pound difference affects installation difficulty and mounting requirements. You need a stronger wall bracket and more support for the heavier Rellytech system. The lighter COSTWAY unit is easier to handle during the mounting process.
How do the physical dimensions compare for wall mounting?
The Rellytech unit is 39.6 inches wide and 9.5 inches tall. The COSTWAY unit is wider at 44.5 inches but taller at 13 inches. Both are designed for wall mounting. You should measure your available wall space carefully. The Rellytech model is more compact vertically, while the COSTWAY model has a broader horizontal footprint.
Do both models provide heating as well as cooling?
Yes, both units are heat pumps that provide heating and cooling. The Rellytech 19 SEER2 model lists heating as its primary operating mode. The COSTWAY 20 SEER2 model also supports heating operations. You can use both systems year-round for temperature control in your designated room or space.
Which unit is better for a small bedroom?
The COSTWAY 12000 BTU model is better for small bedrooms. It covers up to 750 square feet, which fits typical bedroom sizes. The Rellytech 18000 BTU unit covers 1,250 square feet, which may be too powerful for a small room. Oversized units can cause short cycling and humidity issues in smaller spaces.