# TOSOT Cosmo 9,000 BTU wall mount system

> TOSOT Cosmo 9,000 BTU wall mount system (TST-SU-C9K23) is a 9,000 BTU system from TOSOT Cosmo. It has a wall mount indoor unit, runs on 208/230V, is rated 20.5 SEER2, has an HSPF2 of 8.8, uses R-32 refrigerant, and comes with a 16 ft line set. Lowest in-stock price on file: $699.99 at TOSOT (checked Oct 14, 2026).

- Line: [TOSOT Cosmo](https://minisplitfacts.com/lines/tosot-cosmo/)
- Category: [Single-zone systems](https://minisplitfacts.com/compare/single-zone/)
- Size tier within its line: 9k
- Status: current
- Data confidence: confirmed (last verified 2026-10-14; [what this means](https://minisplitfacts.com/how-we-compare/#confidence))
- Page: https://minisplitfacts.com/products/tosot-cosmo-9k-wall/

## Specifications

| Spec | Value | Source |
|---|---|---|
| Model number | TST-SU-C9K23 | [tosotdirect.com](https://tosotdirect.com/products/9-000-btu-ductless-mini-split-inverter-heat-pump-air-conditioner-230v) (brand, page, 2026-10-14) |
| Size | 9,000 BTU/h | [tosotdirect.com](https://tosotdirect.com/products/9-000-btu-ductless-mini-split-inverter-heat-pump-air-conditioner-230v) (brand, page, 2026-10-14) |
| Indoor unit style | Wall mount | [tosotdirect.com](https://tosotdirect.com/products/9-000-btu-ductless-mini-split-inverter-heat-pump-air-conditioner-230v) (brand, page, 2026-10-14) |
| Voltage | 208/230V | [tosotdirect.com](https://tosotdirect.com/products/9-000-btu-ductless-mini-split-inverter-heat-pump-air-conditioner-230v) (brand, page, 2026-10-14) |
| SEER2 (cooling efficiency) | 20.5 | [tosotdirect.com](https://tosotdirect.com/products/9-000-btu-ductless-mini-split-inverter-heat-pump-air-conditioner-230v) (brand, page, 2026-10-14) |
| EER2 (efficiency at 95 °F) | not published |  |
| HSPF2 (heating efficiency) | 8.8 | [tosotdirect.com](https://tosotdirect.com/products/9-000-btu-ductless-mini-split-inverter-heat-pump-air-conditioner-230v) (brand, page, 2026-10-14) |
| Rated cooling capacity | not published |  |
| Heating capacity at 47 °F | not published |  |
| Heating capacity at 17 °F | not published |  |
| Heating capacity at 5 °F | not published |  |
| COP at 5 °F | not published |  |
| Heats down to | not published |  |
| Refrigerant | R-32 | [tosotdirect.com](https://tosotdirect.com/products/9-000-btu-ductless-mini-split-inverter-heat-pump-air-conditioner-230v) (brand, page, 2026-10-14) |
| ENERGY STAR certified | not published |  |
| ENERGY STAR cold climate | not published |  |
| Line connection | Flare | [tosotdirect.com](https://tosotdirect.com/products/9-000-btu-ductless-mini-split-inverter-heat-pump-air-conditioner-230v) (brand, page, 2026-10-14) |
| Line set included | 16 ft | [tosotdirect.com](https://tosotdirect.com/products/9-000-btu-ductless-mini-split-inverter-heat-pump-air-conditioner-230v) (brand, page, 2026-10-14) |
| Wi-Fi control | not published |  |
| Indoor sound level (quietest) | not published |  |
| Outdoor sound level | 41 dB(A) | [tosotdirect.com](https://tosotdirect.com/products/9-000-btu-ductless-mini-split-inverter-heat-pump-air-conditioner-230v) (brand, page, 2026-10-14) |
| Compressor warranty | not published |  |
| Parts warranty | not published |  |
| Warranty if you install it yourself | Licensed installer required | [tosotdirect.com](https://tosotdirect.com/pages/warranty-returns) (brand, page, 2026-10-14) |
| Outdoor unit size (W×D×H) | 28.8 × 13 × 21.9 in | [tosotdirect.com](https://tosotdirect.com/products/9-000-btu-ductless-mini-split-inverter-heat-pump-air-conditioner-230v) (brand, page, 2026-10-14) |
| Indoor unit size (W×D×H) | 32.9 × 7.9 × 10.8 in | [tosotdirect.com](https://tosotdirect.com/products/9-000-btu-ductless-mini-split-inverter-heat-pump-air-conditioner-230v) (brand, page, 2026-10-14) |
| Outdoor unit weight | 52.9 lb | [tosotdirect.com](https://tosotdirect.com/products/9-000-btu-ductless-mini-split-inverter-heat-pump-air-conditioner-230v) (brand, page, 2026-10-14) |

## Where to buy

| Store | Price (USD) | Availability | Checked | Link |
|---|---|---|---|---|
| TOSOT | $699.99 | in stock | 2026-10-14 | [View at TOSOT](https://tosotdirect.com/products/9-000-btu-ductless-mini-split-inverter-heat-pump-air-conditioner-230v) |

Prices are re-checked weekly; a date more than a month old means the store could not be re-read.

## The equivalent in other lines

Same category, same size tier (9k), different line:

- [ACiQ Extreme 9,000 BTU ceiling cassette system](https://minisplitfacts.com/products/aciq-extreme-9k-cassette/) — $1,849.99
- [ACiQ Extreme 9,000 BTU slim ceiling cassette system](https://minisplitfacts.com/products/aciq-extreme-9k-cassette-slim/) — $2,099.99
- [ACiQ Extreme 9,000 BTU floor console system](https://minisplitfacts.com/products/aciq-extreme-9k-console/) — $1,899.99
- [ACiQ Extreme 9,000 BTU concealed duct system](https://minisplitfacts.com/products/aciq-extreme-9k-duct/) — $1,999.99
- [ACiQ Extreme 9,000 BTU wall mount system](https://minisplitfacts.com/products/aciq-extreme-9k-wall/) — $1,499.99
- [ACiQ single-zone 9,000 BTU 115V wall mount system](https://minisplitfacts.com/products/aciq-single-zone-9k-115v-wall/) — $909.99
- [ACiQ single-zone 9,000 BTU wall mount system](https://minisplitfacts.com/products/aciq-single-zone-9k-wall/) — $929.99
- [ACiQ Standard 9,000 BTU 115V wall mount system](https://minisplitfacts.com/products/aciq-standard-9k-115v-wall/) — $959.99


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MiniSplit Facts lists modular tool storage from every brand side by side, with a source for every spec. [How we compare](https://minisplitfacts.com/how-we-compare/). Data as of 2026-10-14.