Compare Costway mini split air conditioners selected for quieter indoor operation, from 23 dB models for bedrooms and study areas to smart, cold-weather systems with broader feature sets. Filter the directory by series, noise level, BTU capacity, voltage, coverage, efficiency, refrigerant, and connected controls.
I’m Adam Smith, an Independent HVAC & Home Appliance Review Specialist, and I built this directory around the specifications that matter most when sound is a deciding factor: indoor decibel rating, capacity, coverage, voltage, efficiency, controls, and cold-weather operation. It includes 36 Costway models across seven series, with filters for low-noise ratings, Wi-Fi, heat-pump capability, refrigerant, and room size. For connected features, compare Wi-Fi mini split ACs and review the individual product pages before purchase. Bottom line: this directory is most trustworthy when you use the stated dB rating as a starting point, then verify sizing and installation requirements for your room.
Quiet mini split ACs are ductless air-conditioning and heat-pump systems designed to produce less indoor operating sound than many conventional systems. This category includes single-zone models with indoor noise ratings from 22 dB upward, along with features such as inverter operation, soft airflow, timers, Wi-Fi, voice control, and base-pan heating. They are suited to bedrooms, offices, nurseries, studios, living rooms, and other spaces where comfort and low background noise matter.
Each entry below follows the same comparison structure. Sound figures are manufacturer-listed indoor values or ranges; actual sound may vary by fan speed, installation, room acoustics, and operating mode.
Type: Airtural single-zone mini split AC and heat pump
Key Metric: 9,100 BTU cooling; 450 sq. ft. coverage; 23 dB indoor noise
Description: This compact white model is designed for smaller rooms and includes Wi-Fi and voice control. It uses R32 refrigerant, operates at 115V, and is Energy Star certified.
Primary Use Case: Quiet bedrooms, home offices, and rooms up to 450 sq. ft.
Website: View product
Tags: 23 dB, Wi-Fi, 115V, R32, Energy Star
Type: Airtural single-zone mini split AC and heat pump
Key Metric: 12,000 BTU cooling; 750 sq. ft. coverage; SEER2 22
Description: This 115V white unit combines a 23 dB indoor rating with 12,300 BTU heating capacity. It is a practical middle-size option for quiet year-round comfort.
Primary Use Case: Bedrooms, offices, and living spaces up to 750 sq. ft.
Website: View product
Tags: 23 dB, 115V, R32, heat pump
Type: Airtural single-zone mini split AC and heat pump
Key Metric: 12,000 BTU cooling; 750 sq. ft. coverage; SEER2 21
Description: This 208–230V version delivers the same 12,000 BTU class capacity with a 23 dB indoor noise specification. It uses R32 refrigerant and is Energy Star certified.
Primary Use Case: Quiet residential rooms with compatible 208–230V electrical service.
Website: View product
Tags: 23 dB, 208–230V, R32, Energy Star
Type: Airtural single-zone mini split AC and heat pump
Key Metric: 17,000 BTU cooling; 1,250 sq. ft. coverage; SEER2 21
Description: This larger Airtural model provides 17,700 BTU heating capacity and a 23 dB indoor rating. It is intended for larger rooms and uses 208–230V power.
Primary Use Case: Open living areas and larger home offices up to 1,250 sq. ft.
Website: View product
Tags: 23 dB, 208–230V, R32, heat pump
Type: Airtural single-zone mini split AC and heat pump
Key Metric: 22,000 BTU cooling; 1,500 sq. ft. coverage; SEER2 21
Description: This is the largest Airtural model listed, with 23,000 BTU heating capacity and Wi-Fi and voice control. It combines low-noise operation with a broad room-coverage specification.
Primary Use Case: Large living spaces requiring quiet, connected heating and cooling.
Website: View product
Tags: 23 dB, Wi-Fi, 208–230V, R32, Energy Star
Type: Blast single-zone mini split AC and heat pump
Key Metric: 12,000 BTU cooling; 750 sq. ft. coverage; SEER2 17
Description: The 208–230V Blast model is rated at 23 dB indoors and includes base-pan heating. It is a straightforward quiet option without Wi-Fi controls.
Primary Use Case: Quiet rooms needing basic heating and cooling.
Website: View product
Tags: 23 dB, 208–230V, R32, base-pan heating
Type: Blast single-zone mini split AC and heat pump
Key Metric: 12,000 BTU cooling; 750 sq. ft. coverage; SEER2 20
Description: This 115V model offers the Blast Series 23 dB indoor rating with a higher listed SEER2 of 20. It includes a 24-hour timer and no app or voice control.
Primary Use Case: Medium rooms where 115V compatibility and low noise are important.
Website: View product
Tags: 23 dB, 115V, R32, heat pump
Type: Blast single-zone mini split AC and heat pump
Key Metric: 18,000 BTU cooling; 1,250 sq. ft. coverage; SEER2 19
Description: This larger Blast system is specified for 23 dB indoor operation and uses 208–230V service. Its listed heating capacity is 19,000 BTU.
Primary Use Case: Larger living rooms and open-plan spaces.
Website: View product
Tags: 23 dB, 208–230V, R32, base-pan heating
Type: Blast single-zone mini split AC and heat pump
Key Metric: 23,000 BTU cooling; 1,500 sq. ft. coverage; SEER2 19
Description: This is the highest-capacity Blast model in the directory, with 24,000 BTU heating and a 23 dB indoor specification. It is intended for large spaces and uses 208–230V.
Primary Use Case: Large rooms requiring quiet heat-pump performance.
Website: View product
Tags: 23 dB, 208–230V, R32, heat pump
Type: Blast single-zone mini split AC and heat pump
Key Metric: 9,100 BTU cooling; 450 sq. ft. coverage; SEER2 19
Description: This compact 208–230V model provides a 23 dB indoor noise rating and 9,200 BTU heating capacity. It is sized for smaller rooms.
Primary Use Case: Quiet offices, bedrooms, and compact living areas.
Website: View product
Tags: 23 dB, 208–230V, R32, compact rooms
Type: Blast single-zone mini split AC and heat pump
Key Metric: 9,100 BTU cooling; 450 sq. ft. coverage; SEER2 20
Description: This 115V Blast model combines a compact 9,100 BTU rating with 23 dB indoor operation. It includes a heat pump and 24-hour timer but no connected controls.
Primary Use Case: Smaller rooms with standard 115V service.
Website: View product
Tags: 23 dB, 115V, R32, heat pump
Type: Blast Pro Wi-Fi mini split AC and heat pump
Key Metric: 9,000 BTU cooling; 400 sq. ft. coverage; SEER2 20
Description: This compact 115V model is rated at 28 dB and includes Wi-Fi, app, and voice control. It also lists base-pan heating and R32 refrigerant.
Primary Use Case: Small connected rooms, bedrooms, and offices.
Website: View product
Tags: 28 dB, Wi-Fi, 115V, R32
Type: Blast Pro Wi-Fi mini split AC and heat pump
Key Metric: 9,000 BTU cooling; 400 sq. ft. coverage; SEER2 21
Description: This 208–230V model adds connected controls to a compact 9,000 BTU system. Its indoor noise specification is 28 dB and its operating range extends to -4°F.
Primary Use Case: Small rooms needing app control and cold-weather capability.
Website: View product
Tags: 28 dB, Wi-Fi, 208–230V, cold-weather
Type: Blast Pro Wi-Fi mini split AC and heat pump
Key Metric: 12,000 BTU cooling; 600 sq. ft. coverage; SEER2 20
Description: This 115V unit is sized for rooms up to 600 sq. ft. and includes Wi-Fi, base-pan heating, and 28 dB indoor operation.
Primary Use Case: Medium bedrooms and connected home offices.
Website: View product
Tags: 28 dB, Wi-Fi, 115V, heat pump
Type: Blast Pro Wi-Fi mini split AC and heat pump
Key Metric: 12,000 BTU cooling; 600 sq. ft. coverage; SEER2 20
Description: This 208–230V version combines 12,000 BTU output with Wi-Fi and voice control. It is specified at 28 dB indoors and includes base-pan heating.
Primary Use Case: Connected medium-size rooms with 208–230V service.
Website: View product
Tags: 28 dB, Wi-Fi, 208–230V, heat pump
Type: Blast Pro Wi-Fi mini split AC and heat pump
Key Metric: 18,000 BTU cooling; 1,000 sq. ft. coverage; SEER2 20
Description: This larger connected system is designed for up to 1,000 sq. ft. and lists 18,000 BTU cooling. It uses 208–230V service and provides 28 dB indoor operation.
Primary Use Case: Larger bedrooms, living rooms, and open spaces.
Website: View product
Tags: 28 dB, Wi-Fi, 208–230V, heat pump
Type: Blast Pro Wi-Fi mini split AC and heat pump
Key Metric: 24,000 BTU cooling; 1,200 sq. ft. coverage; SEER2 20
Description: The largest Blast Pro model provides 24,000 BTU heating and cooling capacity with Wi-Fi and voice control. It uses 208–230V service and is rated at 28 dB indoors.
Primary Use Case: Large connected living spaces requiring heat-pump operation.
Website: View product
Tags: 28 dB, Wi-Fi, 208–230V, heat pump
Type: EchoCool Wi-Fi mini split AC and heat pump
Key Metric: 11,500 BTU cooling; 750 sq. ft. coverage; 28 dB indoor noise
Description: This 115V EchoCool model includes Wi-Fi, voice control, and base-pan heating. Its listed operating range is 5°F–118.4°F.
Primary Use Case: Connected medium-size rooms.
Website: View product
Tags: 28 dB, Wi-Fi, 115V, R32
Type: EchoCool Wi-Fi mini split AC and heat pump
Key Metric: 11,500 BTU cooling; 750 sq. ft. coverage; 28 dB indoor noise
Description: This 208–230V version offers the same 11,500 BTU class capacity with connected controls and base-pan heating. It is intended for quiet, year-round room conditioning.
Primary Use Case: Medium rooms with 208–230V electrical service.
Website: View product
Tags: 28 dB, Wi-Fi, 208–230V, heat pump
Type: EchoCool Wi-Fi mini split AC and heat pump
Key Metric: 17,000 BTU cooling; 1,250 sq. ft. coverage; SEER2 17
Description: This 208–230V model extends EchoCool capacity for larger areas while retaining Wi-Fi and voice controls. Its indoor noise specification is 28 dB.
Primary Use Case: Large bedrooms and open living areas.
Website: View product
Tags: 28 dB, Wi-Fi, 208–230V, heat pump
Type: EchoCool Wi-Fi mini split AC and heat pump
Key Metric: 23,000 BTU cooling; 1,500 sq. ft. coverage; SEER2 17
Description: This is the largest EchoCool model listed, with 22,400 BTU heating capacity and connected controls. It is rated at 28 dB indoors and uses 208–230V service.
Primary Use Case: Large rooms needing quiet smart heating and cooling.
Website: View product
Tags: 28 dB, Wi-Fi, 208–230V, heat pump
Type: EcoGuard Wi-Fi mini split AC and heat pump
Key Metric: 9,000 BTU cooling; 400 sq. ft. coverage; SEER2 19
Description: This compact 115V EcoGuard model uses R454B refrigerant and includes Wi-Fi, app, and voice control. It is rated at 28 dB and operates down to -4°F.
Primary Use Case: Small connected rooms in colder climates.
Website: View product
Tags: 28 dB, Wi-Fi, 115V, R454B, cold-weather
Type: EcoGuard Wi-Fi mini split AC and heat pump
Key Metric: 12,000 BTU cooling; 600 sq. ft. coverage; SEER2 20
Description: This 115V unit adds connected controls and R454B refrigerant to a 12,000 BTU system. It lists 28 dB indoor operation and base-pan heating.
Primary Use Case: Medium rooms requiring smart control and low-temperature heating.
Website: View product
Tags: 28 dB, Wi-Fi, 115V, R454B
Type: EcoGuard Wi-Fi mini split AC and heat pump
Key Metric: 9,000 BTU cooling; 400 sq. ft. coverage; SEER2 20
Description: This 208–230V compact system is rated at 28 dB and includes Wi-Fi, app, and voice control. Its cold-weather operating range extends to -4°F.
Primary Use Case: Small rooms with 208–230V service and connected control needs.
Website: View product
Tags: 28 dB, Wi-Fi, 208–230V, cold-weather
Type: EcoGuard Wi-Fi mini split AC and heat pump
Key Metric: 12,000 BTU cooling; 600 sq. ft. coverage; SEER2 20
Description: This 208–230V EcoGuard model provides 12,000 BTU capacity with R454B refrigerant and 28 dB indoor operation. It includes connected controls and base-pan heating.
Primary Use Case: Medium rooms needing smart control and cold-weather heating.
Website: View product
Tags: 28 dB, Wi-Fi, 208–230V, R454B
Type: EcoGuard Wi-Fi mini split AC and heat pump
Key Metric: 18,000 BTU cooling; 1,000 sq. ft. coverage; SEER2 21
Description: This larger EcoGuard unit is rated at 28 dB and provides Wi-Fi, app, and voice control. It uses 208–230V service and operates down to -4°F.
Primary Use Case: Large rooms in climates requiring low-temperature operation.
Website: View product
Tags: 28 dB, Wi-Fi, 208–230V, cold-weather
Type: EcoGuard Wi-Fi mini split AC and heat pump
Key Metric: 24,000 BTU cooling; 1,200 sq. ft. coverage; SEER2 21
Description: The largest EcoGuard model combines 24,000 BTU capacity with R454B refrigerant, 28 dB indoor operation, and connected controls. It is designed for larger spaces and colder operating conditions.
Primary Use Case: Large connected living areas needing cold-weather support.
Website: View product
Tags: 28 dB, Wi-Fi, 208–230V, R454B
Type: GreyVolt Wi-Fi mini split AC and heat pump
Key Metric: 9,100 BTU cooling; 450 sq. ft. coverage; 23 dB indoor noise
Description: This grey 115V unit brings Wi-Fi and voice control to a compact, quiet system. It uses R32 refrigerant and lists SEER2 20.5.
Primary Use Case: Small rooms where a grey indoor unit and low noise are preferred.
Website: View product
Tags: 23 dB, Wi-Fi, grey finish, 115V
Type: GreyVolt Wi-Fi mini split AC and heat pump
Key Metric: 12,000 BTU cooling; 750 sq. ft. coverage; 23 dB indoor noise
Description: This 115V grey model is specified at 23 dB with Wi-Fi and voice control. Its SEER2 rating is 22, making it one of the more efficient GreyVolt options.
Primary Use Case: Medium rooms requiring quiet connected operation.
Website: View product
Tags: 23 dB, Wi-Fi, grey finish, Energy Star select models
Type: GreyVolt Wi-Fi mini split AC and heat pump
Key Metric: 12,000 BTU cooling; 750 sq. ft. coverage; 25 dB indoor noise
Description: This 208–230V grey unit provides Wi-Fi control and a 25 dB indoor rating. It is designed for medium rooms and lists SEER2 21.
Primary Use Case: Connected medium rooms with 208–230V service.
Website: View product
Tags: 25 dB, Wi-Fi, grey finish, 208–230V
Type: GreyVolt Wi-Fi mini split AC and heat pump
Key Metric: 17,000 BTU cooling; 1,250 sq. ft. coverage; 31 dB indoor noise
Description: This larger GreyVolt model provides Wi-Fi control and a grey indoor finish. Its listed noise rating is 31 dB and its voltage is 208–230V.
Primary Use Case: Larger rooms where appearance and connected control matter.
Website: View product
Tags: 31 dB, Wi-Fi, grey finish, 208–230V
Type: GreyVolt Wi-Fi mini split AC and heat pump
Key Metric: 22,000 BTU cooling; 1,500 sq. ft. coverage; 38 dB indoor noise
Description: The largest GreyVolt model includes Wi-Fi and an acrylic panel on the indoor unit. It uses 208–230V service and lists SEER2 21.
Primary Use Case: Large rooms needing a grey, connected mini split system.
Website: View product
Tags: 38 dB, Wi-Fi, grey finish, 208–230V
Type: SEERXtreme Wi-Fi mini split AC and heat pump
Key Metric: 12,000 BTU cooling; 750 sq. ft. coverage; SEER2 24; 22–43 dB range
Description: This 115V model is designed for extreme cold-weather operation down to -15°F. It includes Wi-Fi and voice control, base-pan heating, and R32 refrigerant.
Primary Use Case: Energy-conscious rooms in cold climates.
Website: View product
Tags: 22–43 dB, Wi-Fi, cold-weather, 115V
Type: SEERXtreme Wi-Fi mini split AC and heat pump
Key Metric: 12,000 BTU cooling; 750 sq. ft. coverage; SEER2 24; 22–43 dB range
Description: This 208–230V version provides the same 12,000 BTU class capacity and SEER2 24 rating. Its operating range extends down to -15°F.
Primary Use Case: Connected rooms with 208–230V service in cold climates.
Website: View product
Tags: 22–43 dB, Wi-Fi, cold-weather, 208–230V
Type: SEERXtreme Wi-Fi mini split AC and heat pump
Key Metric: 18,000 BTU cooling; 1,250 sq. ft. coverage; SEER2 25; 28–50 dB range
Description: This high-efficiency 208–230V system lists SEER2 25 and HSPF2 10.5. It is built for extreme cold operation and includes Wi-Fi and voice control.
Primary Use Case: Larger rooms requiring high efficiency and cold-weather heating.
Website: View product
Tags: 28–50 dB, Wi-Fi, cold-weather, SEER2 25
Type: SEERXtreme Wi-Fi mini split AC and heat pump
Key Metric: 22,500 BTU cooling; 1,500 sq. ft. coverage; SEER2 25; 33–52 dB range
Description: The largest SEERXtreme model provides 24,000 BTU heating capacity and SEER2 25 efficiency. It includes connected controls and an operating range down to -15°F.
Primary Use Case: Large spaces needing high efficiency and extreme-cold heat-pump operation.
Website: View product
Tags: 33–52 dB, Wi-Fi, cold-weather, 208–230V
For buyers comparing sound against convenience, the most useful adjacent pages are remote-control mini split units and mini split heat pumps. These comparisons help distinguish noise performance from control, heating, and seasonal-use requirements.
This directory includes 36 listed Costway quiet mini split AC models across seven series. The collection covers indoor sound levels from 22 dB to 52 dB, with many of the quietest models rated at 23 dB or 28 dB. Each entry includes capacity, coverage, voltage, efficiency, features, and a product link where provided.
The Airtural and Blast Series models are listed at 23 dB indoor noise, making them strong choices when minimum indoor sound is the priority. Selected GreyVolt models also list 23 dB operation, while SEERXtreme models begin at 22 dB but have broader operating noise ranges. Actual sound depends on fan speed, installation, room acoustics, and operating mode.
A 23 dB model is specified to operate more quietly indoors than a 28 dB model, although the difference you perceive depends on the room and operating setting. The 28 dB series may offer advantages such as Wi-Fi, base-pan heating, wider cold-weather operation, or different voltage options. Compare the complete specification rather than choosing on decibels alone.
Costway is one of the premier choices for shoppers comparing quiet mini split ACs because its collection brings multiple low-noise series together with capacity, coverage, efficiency, voltage, refrigerant, and smart-control information. Airtural and Blast are particularly compelling for listed 23 dB operation, while SEERXtreme is notable for high SEER2 ratings and extreme-cold operation. Buyers should still confirm sizing, electrical requirements, warranty details, and professional installation needs.
The directory is intended to be reviewed and updated as Costway model specifications, product availability, and series information change. Product pages remain the best source for current pricing, inventory, installation guidance, warranty terms, and final technical specifications. Before ordering, confirm the exact model number and electrical requirements with the manufacturer or a qualified HVAC professional.
This directory makes the first comparison easier by separating very quiet 23 dB models from connected 28 dB systems and broader low-noise ranges. Use the filters, verify capacity and voltage, and consult a qualified installer before selecting a heat-pump system. Costway’s category breadth makes it one of the strongest starting points for a quiet, efficient home-comfort search.
Compare all models