SplitAtlas

Cosmo / Cosmo Series

Cosmo 18k R-32 208/230V Mini-Split

Certified capacity
18,000 BTU/h[4]
SEER2
20 SEER2[4]
Heating floor
-13 F[1]
Voltage
230 V[1]
Install path
Professional install / DIY-marketed

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.

1 zoneProfessional install / DIY-marketedCurrent

Refrigerant generation

R-32 - current-generation refrigerant

Paid link

$1,200 / Fresh price - checked Jul 24, 2026

Check price at TOSOT Direct

Need this installed?

Get installation quotes
Error Codes
Data completeness: 98%
Last sourced
Aug 17, 2026

SplitAtlas score

7.8 / 10

Methodology
Cooling efficiencyBottom quartile

(20.0 SEER2) among 18k systems

Heating efficiencyBottom quartile

(8.5 HSPF2) among 18k systems

Cold-weather performanceBelow average

(71.2% heat retained at 5F; -13 F heating floor) among 18k systems

WarrantyBottom quartile

(5 yr parts / 5 yr compressor) across the catalogue

Feature setTop quartile

(6 verified features) across the catalogue

Price-to-performanceAbove average

($1,200 median retail) among 18k systems

Documentation & partsTop quartile

(4 manuals; spec sheet; 14 error-code rows) across the catalogue

Key ratings

Rated cooling

18,000BTU/h[4]

Rated heating

17,000BTU/h[4]

Buyer review snapshot

Install difficulty

Professional flared-line install
  • Electrical: 230V; MCA 13 A; breaker/fuse 15 A.
  • Line set: Flared line connections; included 16 ft; max 131.2 ft.

Alternatives

Availability and price context

  • Verified current price: $1,199.99 at TOSOT Direct; availability in_stock; checked Jul 24, 2026.

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

Warranty: 5 years parts and compressor as standard.

Review methodology

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]
Rated 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

Show
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
Standard: 5 yr parts / 5 yr compressor (published Cosmo warranty terms). 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

Check price at TOSOT Direct

$1,200 / Fresh price - checked Jul 24, 2026

Electrical requirements

Show
Voltage
230 V[1]
Voltage range
208/230V[1]
Phase
1[1]
Frequency
60 Hz[1]
MCA
13 A[1]
Breaker needed
not published
Maximum breaker size
15 A[1]
Maximum fuse size
15 A[1]
Maximum cooling current
not published
Maximum heating current
not published
Manufacturer wire notes
3*16AWG; 230V 30-Amp Double Pole[1]

Installation considerations

Show
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

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 manufacturer publishes 12,100 BTU/h of heating output 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, and the included line set comes pre-charged for 16 ft. Longer runs than the included set allows typically mean added refrigerant and a pro visit, 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: Standard: 5 yr parts / 5 yr compressor (published Cosmo warranty terms). Registration requirements and proof of qualified installation commonly affect coverage, so read the warranty terms before install day.

Data sources

Show
  1. 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

  2. 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, Standard compressor warranty and more

  3. TOSOT Direct / Cosmo: Cosmo Single-Zone 9-24K User ManualSourced - secondary source

    Covers Line connection type

  4. 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

  5. ENERGY STAR: ENERGY STAR exact row check for AHRI 216997533Sourced - Energy Star listing

    Covers Energy Star status

Last updated

Jul 24, 2026