MRCOOL DIYHH-18 Hyper Heat 18K Mini Split Complete DIY Bundle – 5th Gen (230V)

PRODUCT DESCRIPTION 

MRCOOL DIYHH-18 Hyper Heat 18K Complete DIY Mini Split Bundle (230V)

 Model bundle: MRD-DIYHH18-WM18-25

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

Line Set Length Info

This system includes a standard 25 ft. line set. Extended line set options add an additional line set, couplers, and a longer control wire for installations requiring extra distance.

 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

 IDEAL USES

• Master bedrooms
• Garage conversions or bonus rooms
• Basements & attics
• Home gyms & studios
• Offices or retail suites
• Barndominiums
• Pole barns & detached buildings
• Cabins & mountain homes
• Airbnb & rental units where comfort = reviews

If you heat with space heaters, oil, or propane — Hyper Heat will save you money the first winter.

SPECIFICATIONS (CONDENSER – DIYHH-18-HP-C-230D25-O)

BTU Heating / Cooling: 18,000

Voltage: 208/230V

Phase: 1

Cycles: 60 Hz

SEER2: 21.2

HSPF2: 11

Max Coverage: 800 sq ft

Refrigerant: R-454B

Inverter: Yes — Hyper Heat

Min Ambient Heat: -22°F

Min Ambient Cool: -22°F

Noise Level: 58 dBA

Compressor Type: Rotary

Metering Device: EEV

Energy Star: Yes

AHRI Certified: Yes

ELECTRICAL

Max Fuse / Breaker: 25A

Minimum Circuit Ampacity (MCA): 19A

Line Set Included: 25ft QuickConnect® No-Vac

Liquid Line: 1/4

Suction Line: 1/2

Max Line Length: 75 ft

 

Specifications (Ceiling Cassette – DIYCASSETTE18HP-230D25-O)

BTU: 12,000 or 18,000 depending install

Coverage: up to 550 sq ft

Mount Type: Flush ceiling 16” joists

Decibel: 24–41 dBA (Ultra Quiet)

Air Direction: 1-way low profile

Filter: Reusable

Modes: Auto / Sleep / Dry / Fan Only

Smart Home: Alexa • Google Assistant • Wi-Fi App

Breaker Size: 15A dedicated

MCA: 3A

 ELECTRICAL NOTE

Each outdoor unit requires its own dedicated power circuit.

This prevents installation mistakes and warranty issues.

 HYPER HEAT VS STANDARD DIY

Standard DIY units are excellent above freezing.

Hyper Heat maintains real heating output down to -22°F using a stronger inverter, advanced coil temperature management, and higher torque compressor logic.

If your winter dips below 20°F — choose Hyper Heat.

 FREQUENTLY ASKED QUESTIONS

 Can I install this myself?

Yes.

This bundle uses factory-sealed No-Vac® QuickConnect® line sets.

No EPA license, no nitrogen purge, no vacuum pump, no gauges.

Do I need to buy refrigerant?

No.

Everything is pre-charged at the factory.

 Is this better than a window unit or portable AC?

Not even close.

Hyper Heat systems are:

• Quieter
• More efficient
• Safer
• Built to run year-round
• Permanent HVAC, not a temporary appliance

 Will it heat in extreme cold?

Yes.

Full usable heating down to -22°F, unlike standard heat pumps.

 Can I use this in a rental or Airbnb?

Absolutely.

It increases property value and lowers complaints.

Will this work in a detached shop or garage?

Yes — Hyper Heat is designed for problem spaces.

 
WHY BUY FROM US

We are USA’s #1 Most Trusted MRCOOL Dealer — specializing only in MRCOOL.

You’re not buying from a random dropshipper.

Our HVAC team will verify sizing, breaker requirements, and line sets before you order.

 Call  us anytime with questions.

We will make sure you get the exact system you need — not what a competitor guesses.