Introducing New 2025 the newest generation of true cold-climate MRCOOL® comfort—the DIYHH-18 Hyper Heat 18K Mini Split. This 5th Gen system delivers powerful year-round performance, pushing full heating output down to -22°F, something standard mini-splits simply cannot achieve. Designed specifically for homeowners and installers who want a reliable DIY 18K Hyper Heat condenser, this bundle uses the No-Vac® QuickConnect® pre-charged line set, eliminating the need for vacuum pumps, refrigerant handling, EPA certification, or special tools.

This 18,000 BTU single-zone system efficiently heats and cools up to 800 sq ft, making it ideal for garages, bonus rooms, apartments, basements, shops, master bedrooms, offices, cabins, or outbuildings. The advanced Hyper Heat inverter technology dynamically adjusts compressor RPM to maintain stable performance in extreme weather instead of cycling like a traditional heat pump.

The included 25 ft QuickConnect® line set is factory-sealed and pre-charged with R-454B, delivering future-ready refrigerant technology with excellent low-temp capacity. Combined with the SmartHVAC® App, native Wi-Fi, and full voice control through Amazon Alexa® and Google Assistant®, you can control your system from anywhere. Gold Fin® corrosion protection ensures durability in coastal and humid regions, while ultra-quiet operation keeps noise under 58 dBA.

With premium features like Auto mode, Dry mode, Sleep mode, Timer, and Auto-Restart after power loss, the MRCOOL DIYHH-18 Hyper Heat complete bundle is a true plug-and-play system designed for long-term performance. Every kit includes superior warranty support—7-year compressor + 5-year parts, with optional Lifetime Replacement through MRCOOL® Care registration.

 Hyper Heat vs Standard Mini Splits (Real-world Benefit)

Standard DIY mini splits start to lose heating output below ~25°F.

The MRCOOL DIYHH-18 Hyper Heat continues producing usable BTUs down to -22°F, thanks to:

• Dual-stage inverter logic
• R-454B refrigerant performance curve
• Optimized EEV metering
• Cold-climate coil design

 If you live where winter hits freezing… Hyper Heat is the correct choice.

INCLUDES IN THIS COMPLETE DIY BUNDLE:

✔ DIYHH-18-HP-C-230D25-O – Hyper Heat 18K Outdoor Condenser (R-454B)
✔DIYCASSETTE18HP-230D25-O –MRCOOL® DIY® Series 5th Gen OuttaSight® 18K BTU 230V One-Way Ceiling Cassette
✔ DIY25-1412 – 25ft Pre-Charged QuickConnect® Line Set
✔ DIYPRO® Communication Cable

 WHY CHOOSE THIS BUNDLE

• True Hyper Heat performance to -22°F
• Real DIY installation — no vacuuming, no gauges
• Factory-sealed Quick Connect system
• Consistent room temperature (no rapid on/off cycling)
• Lower energy bills vs space heaters or window ACs
• Quiet operation with premium inverter control
• Future-proof R-454B refrigerant
• Premium build for garages, shops, offices, cabins, bonus rooms

This isn’t an entry-level mini split — it is the tool you use when you want to control the cold, not survive it.

  WORKS WITH:
✔ DIY-18-HP-WMAH-230D25-O Wall Mount Air Handler
✔ DIYCASSETTE18HP-230D25-O OuttaSight® Ceiling Cassette