# MRCOOL DIY 5th Gen Hyper Heat 18,000 BTU wall mount system

> MRCOOL DIY 5th Gen Hyper Heat 18,000 BTU wall mount system (DIYHH-18-HP-WM-230D25-O) is a 18,000 BTU system from MRCOOL DIY 5th Gen. It has a wall mount indoor unit, runs on 208/230V, is rated 21.2 SEER2, has an HSPF2 of 11, puts out 18,000 BTU/h of heat at 5 °F, heats down to -22 °F by the brand's rating, uses R-454B refrigerant, comes with a 25 ft line set, and carries a 7-year compressor warranty. Lowest in-stock price on file: $3,173 at HVACDirect (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-hyper-heat-wall/

## Specifications

| Spec | Value | Source |
|---|---|---|
| Model number | DIYHH-18-HP-WM-230D25-O | [hvacdirect.com](https://hvacdirect.com/mrcool-18000-btu-diy-5th-gen-hyper-heat-21-2-seer2-single-zone-wall-mount-mini-split-heat-pump-system-r454b-230v.html) (retailer, page, 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 | Wall mount | [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 | DIYHH-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 | DIY-18-HP-WMAH-230D25-O | [doxrepo.mrcool.com](https://doxrepo.mrcool.com/mc-cat-en-01.pdf) (brand, pdf, 2026-10-14) |
| SEER2 (cooling efficiency) | 21.2 | [energystar.gov](https://www.energystar.gov/productfinder/product/certified-heat-pumps/details/3798940) (certification, feed, 2026-10-14) |
| EER2 (efficiency at 95 °F) | 12.5 | [energystar.gov](https://www.energystar.gov/productfinder/product/certified-heat-pumps/details/3798940) (certification, feed, 2026-10-14) |
| HSPF2 (heating efficiency) | 11 | [energystar.gov](https://www.energystar.gov/productfinder/product/certified-heat-pumps/details/3798940) (certification, feed, 2026-10-14) |
| Rated cooling capacity | 18,000 BTU/h | [energystar.gov](https://www.energystar.gov/productfinder/product/certified-heat-pumps/details/3798940) (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/3798940) (certification, feed, 2026-10-14) |
| Heating capacity at 17 °F | 15,200 BTU/h | [energystar.gov](https://www.energystar.gov/productfinder/product/certified-heat-pumps/details/3798940) (certification, feed, 2026-10-14) |
| Heating capacity at 5 °F | 18,000 BTU/h | [energystar.gov](https://www.energystar.gov/productfinder/product/certified-heat-pumps/details/3798940) (certification, feed, 2026-10-14) |
| COP at 5 °F | 1.99 | [energystar.gov](https://www.energystar.gov/productfinder/product/certified-heat-pumps/details/3798940) (certification, feed, 2026-10-14) |
| Heats down to | -22 °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/3798940) (certification, feed, 2026-10-14) |
| ENERGY STAR certified | yes | [energystar.gov](https://www.energystar.gov/productfinder/product/certified-heat-pumps/details/3798940) (certification, feed, 2026-10-14) |
| ENERGY STAR cold climate | yes | [energystar.gov](https://www.energystar.gov/productfinder/product/certified-heat-pumps/details/3798940) (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) |
| Line set included | 25 ft | [hvacdirect.com](https://hvacdirect.com/mrcool-18000-btu-diy-5th-gen-hyper-heat-21-2-seer2-single-zone-wall-mount-mini-split-heat-pump-system-r454b-230v.html) (retailer, page, 2026-10-14) |
| Wi-Fi control | not published |  |
| Indoor sound level (quietest) | 20.5 dB(A) | [doxrepo.mrcool.com](https://doxrepo.mrcool.com/mc-cat-en-01.pdf) (brand, pdf, 2026-10-14) |
| Outdoor sound level | 58 dB(A) | [doxrepo.mrcool.com](https://doxrepo.mrcool.com/mc-cat-en-01.pdf) (brand, pdf, 2026-10-14) |
| Room size (brand's claim) | 800 sq ft | [doxrepo.mrcool.com](https://doxrepo.mrcool.com/mc-cat-en-01.pdf) (brand, pdf, 2026-10-14) |
| 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) |
| Outdoor unit size (W×D×H) | 35.04 × 13.46 × 26.5 in | [doxrepo.mrcool.com](https://doxrepo.mrcool.com/mc-cat-en-01.pdf) (brand, pdf, 2026-10-14) |
| Indoor unit size (W×D×H) | 42.52 × 8.9 × 13.19 in | [doxrepo.mrcool.com](https://doxrepo.mrcool.com/mc-cat-en-01.pdf) (brand, pdf, 2026-10-14) |
| Outdoor unit weight | 99.87 lb | [doxrepo.mrcool.com](https://doxrepo.mrcool.com/mc-cat-en-01.pdf) (brand, pdf, 2026-10-14) |

## Where to buy

| Store | Price (USD) | Availability | Checked | Link |
|---|---|---|---|---|
| HVACDirect | $3,173 | in stock | 2026-10-14 | [View at HVACDirect](https://hvacdirect.com/mrcool-18000-btu-diy-5th-gen-hyper-heat-21-2-seer2-single-zone-wall-mount-mini-split-heat-pump-system-r454b-230v.html) |

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


---
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.