Cosmo / Cosmo Series
Cosmo 18k R-32 208/230V Mini-Split
The Cosmo 18k is the value 1.5-ton: SEER2 20, EER2 12, HSPF2 8.5 on R-32, with 17,000 BTU at 47F, 15,300 BTU at 17F and 12,100 BTU at 5F. Its EER2 of 12 is a highlight at this size, and it holds better than 70% of rated heat down to 5F. ENERGY STAR certified and Gree-built.
Refrigerant generation
R-32 - current-generation refrigerant
Paid link
$1,200 / Checked Jul 24, 2026
Need this installed?
Get installation quotes- Last sourced
- Aug 17, 2026
SplitAtlas score
7.8 / 10
(20.0 SEER2) among 18k systems
(8.5 HSPF2) among 18k systems
(5F certified capacity: 71.2% of the 47F rating; -13 F heating floor) among 18k systems
(5 yr parts / 5 yr compressor) across the catalogue
(6 verified features) across the catalogue
($1,200 median retail) among 18k systems
(4 manuals; spec sheet; 14 error-code rows) across the catalogue
Key ratings
Buyer review snapshot
Install difficulty
- Electrical: 230V; MCA 13 A; breaker/fuse 15 A.
- Line set: Flared line connections; included 16 ft; max 131.2 ft.
Alternatives
- Blueridge XS6 Max Efficiency 18,000 BTU R-454B 208/230V (BXS6A18WM0 / BXS6A18UC0)
9.2 score / 18k / SEER2 25.6 / -22 F heating floor / 230V
Exact destination at Alpine Home Air: $2,359.00, checked Jul 24, 2026
- Senville ELITE 18,000 BTU R-454B 208/230V (SENE-18EL-IHH / SENE-18EL-OH)
9.0 score / 18k / SEER2 25.6 / -22 F heating floor / 187-253V
Exact destination at Senville: $1,899.99, checked Jul 24, 2026
- ACiQ Standard 18,000 BTU R-454B 208/230V (ACIQ-18WS-HP230C / ACIQ-18ZS-HP230C)
9.0 score / 18k / SEER2 24 / -13 F heating floor / 230V
Exact destination at HVACDirect: $1,299.99, checked Jul 26, 2026
Availability and price context
- Last seen at TOSOT Direct on Jul 24, 2026: $1,199.99. Open the listing for today's price.
Source date
- Model data sourced
- Aug 17, 2026
- Page reviewed
- Jul 24, 2026
- Source-backed records
- 5
- Newest source retrieved
- Aug 17, 2026
Warranty tiers
- Base
- 5 yr parts / 5 yr compressor - published Cosmo warranty terms
The score uses Base. Additional published terms are shown for reference and not counted in the score.
Strengths
- EER2 12 - excellent peak efficiency for a 1.5-ton unit.
- Holds 15,300 BTU at 17F and 12,100 BTU at 5F - strong cold-weather output.
- ENERGY STAR with current R-32 refrigerant; Gree-built value price.
Weaknesses
- HSPF2 8.5 - seasonal heating efficiency trails the premium brands.
- Value-brand support network; professional install recommended.
Climate suitability
- Minimum heating ambient
- -13 F[1]
- Certified heating at 5F
- 12,100 BTU/h[4]
- Rated heating at 17F
- 15,300 BTU/h[4]
- Rated heating at 47F
- 17,000 BTU/h[4]
Specifications
ShowHide
- Manufacturer
- Cosmo
- Brand
- Cosmo
- Product line
- Cosmo Series
- Model number
- GWH18AWDXD-D6DN*/I indoor / GWH18ATDXD-D6DNA1A/O outdoor
- Indoor unit model
- GWH18AWDXD-D6DN*/I
- Outdoor unit model
- GWH18ATDXD-D6DNA1A/O
- Number of zones
- 1
- Max indoor units
- not published
- Rated cooling capacity
- 18,000 BTU/h[4]
- Rated heating capacity
- 17,000 BTU/h[4]
- Voltage
- 230 V[1]
- MCA
- 13 A[1]
- Maximum fuse or breaker size
- 15 A[1]
- Breaker needed
- not published
- SEER2
- 20 SEER2[4]
- EER2
- 12 EER2[4]
- HSPF2 (Region 4)
- 8.5 HSPF2[4]
- HSPF2 (Region 5)
- not published
- COP
- not published
- COP at 47F
- not published
- COP at 5F
- 1.85 COP[4]
- Minimum outdoor heating temperature
- -13 F[1]
- Minimum outdoor cooling temperature
- -13 F[1]
- Maximum outdoor temperature
- 118 F[1]
- Indoor noise range
- 53/30 dB(A)[1]
- Outdoor noise rating
- not published
- Indoor weight
- 28.7 lb[1]
- Outdoor weight
- 70.6 lb[1]
- Refrigerant
- R-32[4]
- Refrigerant charge
- not published
- Manufacturer coverage
- not published
- Line-set size
- 1/4 in liquid / 1/2 in suction
- Included line-set length
- 16 ft[2]
- Maximum line-set length
- 131.2 ft[1]
- Max line set per indoor
- not published
- Maximum elevation difference
- 82 ft[1]
- Max height between indoor units
- not published
- Wi-Fi support
- supported[2]
- Energy Star status
- ENERGY STAR certified[5]
- AHRI certification number
- 215684456[4]
- Warranty
- Base: 5 yr parts / 5 yr compressor (published Cosmo warranty terms). Score uses Base.. 5-year TOSOT Direct Cosmo product-page warranty
- Install path
- Professional install / DIY-marketed
- Marketing install label
- DIY-marketed
- Retail price
- $1,199.99
- Available retailers
- TOSOT Direct
- Manual links
- Cosmo Single-Zone 9-24K User Manual, TOSOT Direct product documents page for Cosmo Series manuals, 18,000 BTU Mini-Split Heat Pump Air Conditioner-230V product-page specifications, TOSOT Cosmo Series brochure specifications for GWH18ATDXD-D6DNA1A
- Specification sheet
- 18,000 BTU Mini-Split Heat Pump Air Conditioner-230V product-page specifications
- Last sourced date
- Aug 17, 2026
Retail purchase context
Some retailer links may earn us a commission at no extra cost; paid relationships never change scores or recommendations. Affiliate disclosure
Paid link
$1,200 / Checked Jul 24, 2026
Electrical requirements
ShowHide
Installation considerations
ShowHide
- Liquid line
- 1/4 in[1]
- Suction line
- 1/2 in[1]
- Line connection type
- Flared line connections[3]
- Precharged length
- not published
- Included line-set length
- 16 ft[2]
- Maximum line-set length
- 131.2 ft[1]
- Max line set per indoor
- not published
- Max height between indoor units
- not published
- Indoor dimensions
- 37.1 in W x 13.1 in H x 9.7 in D[1]
- Outdoor dimensions
- 31.6 in W x 21.9 in H x 13.8 in D[1]
- Indoor weight
- 28.7 lb[1]
- Outdoor weight
- 70.6 lb[1]
- Drain size
- not published
Related systems and guides
- More Cosmo systems
- Cosmo 18k R-32 208/230V 2-Zone Mini-Split
- Daikin ATMOSPHERA 18k R-32 208/230V Mini-Split
- Cosmo 24k R-32 208/230V 2-Zone Mini-Split
- Cooper Hunter One-Way Cassette 18k Regular R-454B 208/230V Mini-Split
- Guide library
- Mini split buying guide
- Single-zone vs multi-zone mini splits
- Troubleshooting
- Do mini splits work in cold weather?
- The best 18,000 BTU mini splits of 2026
- The best cold-climate mini splits of 2026
- The best mini splits for heating of 2026
- Mini split heating capacity in the cold: what your unit actually delivers at 5F
- The mini split defrost cycle, explained
- The best DIY mini splits of 2026
- What "DIY mini split" actually means
- How to install a mini split (DIY overview)
- R-32 vs R-454B: the mini split refrigerant change explained
- Mini split not heating
- Mini split indoor unit freezing up
- Mini split remote not working
- Your mini split is showing a refrigerant leak code
- Mini split outdoor unit not running
- Line sets
- Line-set covers
Frequently asked questions
- Can I install the Cosmo Series 18,000 BTU R-32 208/230V (GWH18AWDXD-D6DN***/I / GWH18ATDXD-D6DNA1A/O) myself, or do I need a pro?
- Cosmo Series 18,000 BTU R-32 208/230V (GWH18AWDXD-D6DN***/I / GWH18ATDXD-D6DNA1A/O) is built for professional installation: the line set must be flared, evacuated, and charged, which requires EPA-certified refrigerant handling. Installing it outside the manufacturer's requirements can void the warranty, so budget for a qualified HVAC installer.
- Will the Cosmo Series 18,000 BTU R-32 208/230V (GWH18AWDXD-D6DN***/I / GWH18ATDXD-D6DNA1A/O) keep heating in a cold winter?
- The AHRI/ENERGY STAR certification lists 12,100 BTU/h of heating capacity at 5F. Rated heating operation extends down to -13 F. Certified heating efficiency is 8.5 HSPF2. Match those numbers against your climate's design temperature - in cold regions, output at 5F matters far more than the nameplate capacity measured at 47F.
- What electrical circuit does the Cosmo Series 18,000 BTU R-32 208/230V (GWH18AWDXD-D6DN***/I / GWH18ATDXD-D6DNA1A/O) need?
- Published electrical requirements: 230 V voltage, 13 A minimum circuit ampacity, and 15 A maximum breaker or fuse sizing. Confirm the final circuit against the unit nameplate and local code with a licensed electrician.
- How far can the outdoor unit be from the indoor head?
- The published maximum line-set length is 131.2 ft. A 16 ft line set is included. Longer runs than the included set allows require a different line set, so measure the planned routing before ordering.
- What warranty does the Cosmo Series 18,000 BTU R-32 208/230V (GWH18AWDXD-D6DN***/I / GWH18ATDXD-D6DNA1A/O) carry?
- The manufacturer publishes these warranty tiers: Base: 5 yr parts / 5 yr compressor (published Cosmo warranty terms). Score uses Base.. Registration requirements and proof of qualified installation commonly affect coverage, so read the warranty terms before install day.
Data sources
ShowHide
- TOSOT Direct: TOSOT Residential and Light Commercial Split Systems brochure Cosmo table for GWH09ATCXB-D6DNA1CSourced - manufacturer technical document
Covers Frequency, Maximum breaker size, Maximum fuse size, Minimum circuit ampacity, Phase, Manufacturer wire notes and more
- TOSOT Direct: 18,000 BTU Mini-Split Heat Pump Air Conditioner-230V official product pageSourced - manufacturer product page
Covers Included line-set length, Wi-Fi support, Retail price, Legacy compressor warranty value, Legacy warranty value, Base compressor warranty and more
- TOSOT Direct / Cosmo: Cosmo Single-Zone 9-24K User ManualSourced - secondary source
Covers Line connection type
- AHRI certificate #215684456 - search the AHRI DirectorySourced - AHRI directory
Covers AHRI certification number, Rated cooling capacity, COP at 5F, EER2, Rated heating capacity, HSPF2 (Region 4) and more
- ENERGY STAR: ENERGY STAR exact row check for AHRI 216997533Sourced - Energy Star listing
Covers Energy Star status
Last updated
Jul 24, 2026