Choosing a MRCOOL Single Zone Mini Split
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MRCOOL is best known for bringing ductless mini splits to do-it-yourselfers. A mini split is a heating and cooling system with two parts: an indoor air handler mounted high on a wall and an outdoor unit called a condenser, connected by a copper “line set” that carries refrigerant. “Single zone” means one indoor unit for one room or open area. MRCOOL’s DIY models come with line sets that are pre-charged with refrigerant and use quick-connect fittings, so many homeowners can install them without the special tools an HVAC technician would use.
These six systems differ mainly in size (BTU), voltage and whether you can install them yourself. They range from a 9,000 BTU 115V unit for a bedroom to 18,000 BTU 230V systems for large spaces, plus one multi-zone kit for readers who need more than one room.
MRCOOL Single Zone Mini Splits Compared
| Model | BTU and coverage | Voltage | Line set | Install type |
|---|---|---|---|---|
| MRCOOL 5th Gen 9,000 BTU | 9,000, up to 400 sq ft | 115V | 16 ft | Not listed |
| MrCool DIY Multi Zone | 18,000, 750-900 sq ft over 3 zones | 240V | Quick Connect, length not listed | DIY |
| MrCool DIY Select 12K | 12,000, 500-1,200 sq ft | 120V | 11.5 ft pre-charged | DIY |
| MRCOOL DIY Select 18K | 18,000, up to 800 sq ft | 230V | 11.5 ft pre-charged | DIY |
| MRCOOL 12000 BTU 115V 5th Gen DIY | 12,000, up to 550 sq ft | 115V | 25 ft pre-charged | DIY |
| MRCOOL 18000 BTU Advantage | 18,000, up to 750 sq ft | 220V (title says 230V) | Not listed | Professional |
MRCOOL 5th Gen 9,000 BTU Single for a Bedroom or Office
Best for: One bedroom or office on 115V
Pros
- 9,000 BTU for up to 400 sq ft
- 115V household power
- WiFi app control
- 16 ft line set included
Cons
- DIY install not stated
- Efficiency ratings not listed
The MRCOOL 5th Gen 9,000 BTU Single zone system is the smallest here. BTU (British Thermal Unit) measures how much heat a system can move in an hour, so a lower number suits a smaller room. The description calls it a 5th Generation Advantage mini split for spaces up to 400 square feet and says it provides both heating and cooling, though the spec sheet lists only cooling as the operating mode. It runs on 115V power, the same voltage as a standard household outlet circuit.
It comes with a 16-foot line set and a WiFi-enabled wall-mounted air handler, and you can control it through an app or remote. The listing names smart home compatibility, gold fin corrosion resistance (a coating that protects the outdoor coil), Follow Me temperature control, which reads the temperature at the remote rather than the wall unit, and low temperature cooling. Noise is 52.5 dB and the refrigerant is R-454B. The listing does not say whether the line set is pre-charged for DIY, and it gives no SEER2 or HSPF2 efficiency numbers.
This suits a single bedroom, home office or small addition. Because the install method is not stated, plan on asking an installer unless the box confirms quick-connect DIY fittings. For a larger room on the same household voltage, the 12,000 BTU 115V DIY model covers more space.
MrCool DIY Multi Zone Mini Split for Three Rooms
Mrcool Comfort Made Simple
MrCool DIY Multi Zone Mini Split
Price and specifications are read from the Amazon product page and can change.
MrCool DIY Multi Zone Mini Split
Best for: Cooling three rooms, not one
Pros
- Three zones, 750-900 sq ft
- 9 SEER2, 10 HSPF2
- Quick Connect DIY install
- Alexa and Google compatible
Cons
- Multi zone, not single zone
- Needs 240V power
The MrCool DIY Multi Zone Mini Split is included because many single zone shoppers compare it, but it is not a single zone system. It is an 18,000 BTU system with three separate zones for a combined 750 to 900 square feet, so one outdoor unit feeds three indoor units.
The listing gives 23.9 SEER2 cooling efficiency and 10 HSPF2 heating efficiency. SEER2 and HSPF2 measure how efficiently a system cools and heats over a season, and higher is better. It uses Quick Connect technology that the listing says needs no special tools or HVAC training, a variable speed inverter compressor, low ambient cooling, WiFi, Alexa and Google Assistant support, leakage detection and washable filters. It runs on 240V, uses R-454B and lists 60 dB of noise.
Choose this if you need to condition three rooms and have a 240V circuit available. If you only need one room, a true single zone model below is simpler and puts all its capacity where you need it.
MrCool DIY Select Mini Split w Line Set for Big Open Spaces
Mrcool Comfort Made Simple
MRCOOL DIY Select 18K BTU Mini Split Heat Pump, 11.5' Line Set, 230V, White
Price and specifications are read from the Amazon product page and can change.
MRCOOL DIY Select 18K BTU Mini
Best for: Quiet DIY heating and cooling to 800 sq ft
Pros
- 18,000 BTU
- No vacuum pump or brazing
- Silent mode as low as 18.5 dB
- Voice assistant support
Cons
- Needs 230V circuit
- Short 11.5 ft line set
Best for: Large open areas on 120V
Pros
- 12,000 BTU
- Pre-charged 11.5 ft line set
- 5 dB listed
- 1 year labor warranty via seller
Cons
- Wide 500-1,200 sq ft range
- Sold through a third-party seller
The MrCool DIY Select Mini Split w line set is a 12,000 BTU (1 ton) single zone heat pump sold by IWAE with a 1-year labor warranty from that seller. It runs on 120V and includes a pre-charged 11.5-foot quick-connect line set, so you do not handle refrigerant yourself.
The listing gives a range of 17.5 to 16.5 SEER2 cooling and 8.8 to 8.3 HSPF2 heating, with a SEER of 16.5 in the specs, and says it is AHRI certified and Energy Star certified. It has an inverter compressor, which speeds up or slows down instead of switching fully on and off, plus WiFi control through the MrCool Comfort App and a remote. Noise is listed at 44.5 dB. The claimed coverage of 500 to 1,200 square feet is very wide for 12,000 BTU, so for the top of that range, check the manual for climate guidance.
This suits a DIYer with a large living room or garage workshop on standard 120V power who likes the extra labor warranty. For a shorter run and larger capacity, the 18K DIY Select steps up.
MRCOOL DIY Select 18K BTU Mini for Quiet Larger Rooms
The MRCOOL DIY Select 18K BTU Mini split heat pump is a single zone system for rooms up to 800 square feet, running on 230V. It includes an 11.5-foot pre-charged Quick Connect line set, and the listing says no vacuum pump, gauges, brazing or refrigerant handling are needed.
Efficiency is listed at up to 17.3 SEER2 and up to 8.5 HSPF2, with operation as low as 18.5 dB(A) in silent mode overnight, the quietest figure here. It uses an inverter, R-454B refrigerant and the MRCOOL Comfort App, and works with voice assistants. Wattage is 4600 watts.
This is for a DIYer cooling and heating a big family room or open-plan space who has, or can add, a 230V circuit. The short line set means the outdoor unit must sit close to the indoor unit. If you need a longer run, the 25-foot line set on the 12,000 BTU 115V model gives more placement freedom.
MRCOOL 12000 BTU 115V Ductless Inverter for Easy DIY Power
Mrcool Comfort Made Simple
MRCOOL 12000 BTU 115V Ductless Inverter Mini Split Air Conditioner & Heat Pump System, 5th Gen DIY – Wall-Mounted AC Unit w/ Heating and Cooling for Home, Office & Commercial Space
Price and specifications are read from the Amazon product page and can change.
MRCOOL 12000 BTU 115V Ductless Inverter
Best for: DIYers on standard 115V outlets
Pros
- 12,000 BTU up to 550 sq ft
- 25 ft pre-charged line set
- 5 SEER in description
- Energy Star certified
Cons
- Heavy at 120 lb
- Refrigerant listed inconsistently
The MRCOOL 12000 BTU 115V Ductless Inverter is a 5th Gen DIY heat pump system for up to 550 square feet. It includes a 12K condenser, a 12K air handler and a pre-charged 25-foot Quick Connect line set, the longest here. The listing says no special tools, equipment or training are needed and that installation takes a few hours.
The description gives 23.5 SEER and Energy Star certification. It lists dehumidifier, sleep mode, remote control, WiFi and a smart controller module that works with Google Assistant and Amazon Alexa. Noise is 45 dB, wattage 2300 watts and weight 120 pounds. The description mentions R-454A refrigerant while the other 5th Gen models in this list use R-454B, so confirm the refrigerant on the unit label if it matters to you.
This is the most flexible DIY pick for someone without a 230V circuit who wants plenty of line set length. For rooms well over 550 square feet, the 18K models have more capacity.
MRCOOL 18000 BTU 230V Ductless Inverter for Professional Installs
Best for: Buyers hiring an HVAC installer
Pros
- 18,000 BTU up to 750 sq ft
- WiFi enabled
- Washable filter
Cons
- Professional installation required
- Voltage listed as 220V and 230V
The MRCOOL 18000 BTU 230V Ductless Inverter is from the Advantage Series and heats or cools up to 750 square feet. The listing states clearly that installation should be performed by an HVAC technician, so this is not a DIY kit.
It has an inverter, WiFi, remote control, washable filters, copper core material and R-454B refrigerant, with a listed noise of 56 dB. The title says 230V while the specs say 220 volts. No line set length or efficiency ratings are given in the listing.
This suits homeowners who plan to hire a pro and want 18,000 BTU of heating and cooling. If you want to install it yourself, the DIY Select 18K is the equivalent capacity with a pre-charged line set.
How to Choose the Right MRCOOL Single Zone Mini Split
Size by square footage. As a rough guide from these listings, 9,000 BTU covers up to about 400 square feet, 12,000 BTU up to about 550, and 18,000 BTU up to about 750 to 800. Ceiling height, sun exposure and insulation also matter, so size up for hot, sunny rooms.
Check your voltage. The 9,000 and 12,000 BTU models here run on 115V or 120V, while the 18,000 BTU units need a 230V or 220V circuit, which may require an electrician. Our guide to a MRCOOL 110V mini split explains lower-voltage options in more detail.
Decide on DIY or professional install. Models with pre-charged Quick Connect line sets are built for DIY. The Advantage 18,000 BTU unit requires a technician, and the 9,000 BTU listing does not say.
Measure line set length. The distance between indoor and outdoor units must fit the included line set: 11.5 feet on the DIY Select models, 16 feet on the 9K and 25 feet on the 12K 115V. For more on the full lineup, see our overview of the Mr. Cool mini split range.
FAQ
Can I install a MRCOOL mini split myself?
The DIY Select models, the 12,000 BTU 115V 5th Gen DIY and the multi zone kit are built for DIY with pre-charged quick-connect line sets. The Advantage 18,000 BTU requires an HVAC technician.
Do MRCOOL mini splits also heat?
All six are described as providing heating as well as cooling, though the 9,000 BTU spec sheet lists only cooling as its operating mode. Check the manual for its heating range.
What does single zone mean?
One outdoor unit connects to one indoor unit for one room or open area. The multi zone kit connects one outdoor unit to three indoor units.
Which MRCOOL runs on a regular outlet voltage?
The 9,000 BTU (115V), DIY Select 12K (120V) and 12,000 BTU 5th Gen DIY (115V) use household voltage. Always follow the manual for circuit requirements.
What is the quietest model here?
The DIY Select 18K lists operation as low as 18.5 dB(A) in silent mode. The DIY Select 12K lists 44.5 dB.
Which MRCOOL mini split should I buy?
For a bedroom, the 9,000 BTU. For a DIYer on 115V, the 12,000 BTU 5th Gen DIY. For a large room with 230V, the DIY Select 18K.
