# MRCOOL DIY 5th Gen 18,000 BTU ceiling cassette system

> MRCOOL DIY 5th Gen 18,000 BTU ceiling cassette system (DIY-18-HP-C-230D25-O / DIYCASSETTE18HP-230D25-O) is a 18,000 BTU system from MRCOOL DIY 5th Gen. It has a ceiling cassette indoor unit, runs on 208/230V, is rated 21.4 SEER2, has an HSPF2 of 11.5, puts out 13,100 BTU/h of heat at 5 °F, heats down to -13 °F by the brand's rating, uses R-454B refrigerant, and carries a 7-year compressor warranty. Lowest in-stock price on file: $2,822 at Got Ductless (checked Oct 14, 2026).

- Line: [MRCOOL DIY 5th Gen](https://minisplitfacts.com/lines/mrcool-diy-5th-gen/)
- Category: [Single-zone systems](https://minisplitfacts.com/compare/single-zone/)
- Size tier within its line: 18k
- 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/mrcool-diy-5th-gen-18k-cassette/

## Specifications

| Spec | Value | Source |
|---|---|---|
| Model number | DIY-18-HP-C-230D25-O / DIYCASSETTE18HP-230D25-O | [doxrepo.mrcool.com](https://doxrepo.mrcool.com/mc-cat-en-01.pdf) (brand, pdf, 2026-10-14) |
| Size | 18,000 BTU/h | [doxrepo.mrcool.com](https://doxrepo.mrcool.com/mc-cat-en-01.pdf) (brand, pdf, 2026-10-14) |
| Indoor unit style | Ceiling cassette | [doxrepo.mrcool.com](https://doxrepo.mrcool.com/mc-cat-en-01.pdf) (brand, pdf, 2026-10-14) |
| Voltage | 208/230V | [doxrepo.mrcool.com](https://doxrepo.mrcool.com/mc-cat-en-01.pdf) (brand, pdf, 2026-10-14) |
| Outdoor unit model | DIY-18-HP-C-230D25-O | [doxrepo.mrcool.com](https://doxrepo.mrcool.com/mc-cat-en-01.pdf) (brand, pdf, 2026-10-14) |
| Indoor unit model | DIYCASSETTE18HP-230D25-O | [doxrepo.mrcool.com](https://doxrepo.mrcool.com/mc-cat-en-01.pdf) (brand, pdf, 2026-10-14) |
| SEER2 (cooling efficiency) | 21.4 | [energystar.gov](https://www.energystar.gov/productfinder/product/certified-heat-pumps/details/3798936) (certification, feed, 2026-10-14) |
| EER2 (efficiency at 95 °F) | 12.5 | [energystar.gov](https://www.energystar.gov/productfinder/product/certified-heat-pumps/details/3798936) (certification, feed, 2026-10-14) |
| HSPF2 (heating efficiency) | 11.5 | [energystar.gov](https://www.energystar.gov/productfinder/product/certified-heat-pumps/details/3798936) (certification, feed, 2026-10-14) |
| Rated cooling capacity | 18,000 BTU/h | [energystar.gov](https://www.energystar.gov/productfinder/product/certified-heat-pumps/details/3798936) (certification, feed, 2026-10-14) |
| Heating capacity at 47 °F | 18,000 BTU/h | [energystar.gov](https://www.energystar.gov/productfinder/product/certified-heat-pumps/details/3798936) (certification, feed, 2026-10-14) |
| Heating capacity at 17 °F | 13,300 BTU/h | [energystar.gov](https://www.energystar.gov/productfinder/product/certified-heat-pumps/details/3798936) (certification, feed, 2026-10-14) |
| Heating capacity at 5 °F | 13,100 BTU/h | [energystar.gov](https://www.energystar.gov/productfinder/product/certified-heat-pumps/details/3798936) (certification, feed, 2026-10-14) |
| COP at 5 °F | 2.32 | [energystar.gov](https://www.energystar.gov/productfinder/product/certified-heat-pumps/details/3798936) (certification, feed, 2026-10-14) |
| Heats down to | -13 °F | [mrcool.com](https://www.mrcool.com/product/diy-5th-generation) (brand, page, 2026-10-14) |
| Refrigerant | R-454B | [energystar.gov](https://www.energystar.gov/productfinder/product/certified-heat-pumps/details/3798936) (certification, feed, 2026-10-14) |
| ENERGY STAR certified | yes | [energystar.gov](https://www.energystar.gov/productfinder/product/certified-heat-pumps/details/3798936) (certification, feed, 2026-10-14) |
| ENERGY STAR cold climate | yes | [energystar.gov](https://www.energystar.gov/productfinder/product/certified-heat-pumps/details/3798936) (certification, feed, 2026-10-14) |
| Line connection | Quick-connect | [doxrepo.mrcool.com](https://doxrepo.mrcool.com/mc-cat-en-01.pdf) (brand, pdf, 2026-10-14) |
| Wi-Fi control | not published |  |
| Indoor sound level (quietest) | not published |  |
| Outdoor sound level | not published |  |
| Compressor warranty | 7 years | [doxrepo.mrcool.com](https://doxrepo.mrcool.com/mc-diy-5-wr-en-01.pdf) (brand, pdf, 2026-10-14) |
| Parts warranty | 5 years | [doxrepo.mrcool.com](https://doxrepo.mrcool.com/mc-diy-5-wr-en-01.pdf) (brand, pdf, 2026-10-14) |
| Warranty if you install it yourself | Kept | [doxrepo.mrcool.com](https://doxrepo.mrcool.com/mc-diy-5-wr-en-01.pdf) (brand, pdf, 2026-10-14) |

## Where to buy

| Store | Price (USD) | Availability | Checked | Link |
|---|---|---|---|---|
| Got Ductless | $2,822 | in stock | 2026-10-14 | [View at Got Ductless](https://gotductless.com/products/mrcool®-diy-5th-generation-e-star-18-000-btu-22-5-seer2-wall-mounted-heat-pump-system-diy-18-hp-c-230d25-o) |

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 (18k), different line:

- [ACiQ Extreme 18,000 BTU ceiling cassette system](https://minisplitfacts.com/products/aciq-extreme-18k-cassette/) — $2,249.99
- [ACiQ Extreme 18,000 BTU slim ceiling cassette system](https://minisplitfacts.com/products/aciq-extreme-18k-cassette-slim/) — $2,429.99
- [ACiQ Extreme 18,000 BTU floor console system](https://minisplitfacts.com/products/aciq-extreme-18k-console/) — $2,393.99
- [ACiQ Extreme 18,000 BTU concealed duct system](https://minisplitfacts.com/products/aciq-extreme-18k-duct/) — $2,349.99
- [ACiQ Extreme 18,000 BTU wall mount system](https://minisplitfacts.com/products/aciq-extreme-18k-wall/) — $1,899.99
- [ACiQ Standard 18,000 BTU ceiling cassette system](https://minisplitfacts.com/products/aciq-standard-18k-cassette/) — $1,944.99
- [ACiQ Standard 18,000 BTU slim ceiling cassette system](https://minisplitfacts.com/products/aciq-standard-18k-cassette-slim/) — $2,124.99
- [ACiQ Standard 18,000 BTU floor console system](https://minisplitfacts.com/products/aciq-standard-18k-console/) — $2,088.99


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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.