MRCOOL DIY® 5th Gen Hyper Heat 18,000 BTU OuttaSight® Ceiling Cassette Mini-Split Complete System 230V – Single Zone, 500–800 Sq. Ft. | DIYHH-18-HP-CM-230D25

MRCOOL® DIY® 5th Gen Hyper Heat 18,000 BTU OuttaSight® Ceiling Cassette Mini-Split Complete System – Single Zone, 230V The MRCOOL® DIY® 5th Gen Hyper Heat 18,000 BTU OuttaSight® Ceiling Cassette Complete System is the ultimate combination of cold-climate performance and discreet ceiling-mount installation — designed for spaces from 500 to 800 sq. ft. With heating down to -22°F, a 21.2 SEER2 rating, and 11.0 HSPF2-4, this Energy Star certified system delivers reliable comfort in the harshest winters — all with a flush-mounted cassette that disappears into your ceiling. Includes the Hyper Heat condenser, OuttaSight® ceiling cassette air handler, and a 25 ft. pre-charged QuickConnect® line set. Note: uses a 1/2" suction line. Why Choose MRCOOL DIY® 5th Gen Hyper Heat OuttaSight®? Heating to -22°F — The most extreme cold-climate heating in the MRCOOL DIY lineup. Reliable warmth even in the harshest northern winters. Ceiling-Mounted, Out of Sight — Installs flush between standard 16" ceiling joists for a clean, unobtrusive look — no wall space required. 21.2 SEER2 & 11.0 HSPF2-4 — Premium efficiency ratings for maximum year-round energy savings. Energy Star Certified — May qualify for federal tax credits and utility rebates. America’s #1 DIY Mini Split — The most trusted DIY mini split brand in the nation, built for quick setup and long-term reliability. 25 ft. QuickConnect® Line Set Included — Pre-charged with R-454B refrigerant for a fast, vacuum-free installation — no special tools needed. DIYPRO® Armored Cable Included — Eliminates the need for electrical conduit. Built tough to withstand outdoor elements, weather, and wildlife. Advanced Filtration — Improves indoor air quality; Elevation function allows easy filter access for maintenance. Gold Fin® Coil Protection — Superior corrosion resistance, ideal for coastal homes and harsh climates. Smart Connectivity — Control via the SmartHVAC app (iOS & Android), or hands-free with Amazon Alexa or Google Assistant. Best-in-Class Warranty — 7-year compressor warranty + 5-year parts warranty. Certified Excellence — Energy Star Certified, UL Listed, CSA Certified, ETL Certified, AHRI Certified. Product Overview 🏠 Zones: 1 📐 Coverage: 500–800 sq. ft. ❄️ Cold Climate Heating: Down to -22°F outdoor 💨 Air Handler Type: OuttaSight® Ceiling Cassette — 1-Way Airflow 🔧 Installation: DIY — No Professional Required ⚡ Voltage: 208-230V 🌿 Energy Star Certified — May qualify for federal tax credits & utility rebates ⭐ Certification: Energy Star, UL Listed, CSA Certified, ETL Certified, AHRI Certified 🧄 Refrigerant: R-454B ⚠️ Note: Uses 1/2" suction line — verify line set compatibility before ordering What’s in the Box ✅ 18,000 BTU Hyper Heat outdoor condenser ✅ OuttaSight® ceiling cassette air handler ✅ 25 ft. pre-charged QuickConnect® line set (1/4" x 1/2", R-454B) ✅ DIYPRO® armored cable ✅ Remote control Specifications & Dimensions Capacity & Performance Cooling Capacity 18,000 BTU Heating Capacity 18,000 BTU Coverage Area 500–800 sq. ft. SEER2 21.2 EER2 12.5 HSPF2-4 11.0 HSPF2-5 8.5 Cooling Range -5°F to 122°F outdoor Heating Range -22°F to 75°F outdoor Outdoor Noise Level 58 dB(A) Electrical Requirements Voltage 208-230V Phase 1 Cycle 60 Hz Max Fuse Breaker 25A Min Circuit Ampacity 19A Refrigerant & Piping Refrigerant Type R-454B Refrigerant Volume 52.21 oz Liquid Line Size 1/4" Suction Line Size 1/2" Max Line Set Length 75 ft. Dimensions & Weight Condenser Dimensions 35.04" W x 13.46" D x 26.5" H Condenser Weight 99.87 lbs Air Handler Dimensions 50.31" W x 13.19" D x 8.98" H Air Handler Weight 45 lbs Features Inverter Yes Compressor Motor Type Rotary Auto Mode Yes WiFi Compatibility Yes App Compatibility Yes Works with iOS Yes Works with Android Yes Certifications & Warranty Certifications Energy Star Certified, UL Listed, CSA Certified, ETL Certified, AHRI Certified Parts Warranty 5 Years Compressor Warranty 7 Years Shipping & Returns 🚚 Free Curbside Delivery All MRCOOL orders ship free via FedEx Ground, FedEx Freight, or an equivalent trusted carrier. Delivery is curbside only — please arrange assistance in advance as carriers are not able to bring items inside your home. Tracking & Delivery Tracking information is typically provided within 3–5 business days of your order. Once received, please allow 1–2 business days for tracking details to update. ↩️ Return Policy 30-Day Return Window Returns must be requested within 30 days of your delivery date. We are unable to accept return requests after this period. Return Conditions To qualify for a return, items must be unused and uninstalled, and in original packaging including box and pallet. Restocking Fee A 35% restocking fee applies to all approved returns. 📄 View Full Shipping Policy | 📄 View Full Return & Refund Policy Frequently Asked Questions What’s the difference between this and the Hyper Heat 18K wall-mount system? Same Hyper Heat condenser and performance specs — the only difference is the air handler. This system includes the OuttaSight® ceiling cassette (installs flush in the ceiling between 16" joists) instead of a wall-mount unit. Choose this if you want a concealed installation with no wall unit visible. Does the ceiling cassette fit standard joists? Yes — the OuttaSight® cassette fits between standard 16" ceiling joists, including pre-manufactured I-joists, for a flush, concealed installation. What suction line size does this unit use? This unit uses a 1/2" suction line. The included 25 ft. QuickConnect® line set is pre-sized for this unit. If you need a longer run (up to 75 ft. max), make sure any additional line set uses 1/2" suction. Does this qualify for tax credits or rebates? Yes — as an Energy Star certified system with a 21.2 SEER2 and 11.0 HSPF2-4, this unit may qualify for the federal Residential Clean Energy Credit or utility rebate programs. Check with your local utility provider and a tax professional for eligibility. Can I install it myself? Yes. The included 25 ft. pre-charged QuickConnect® line set makes installation vacuum-free. Ceiling installation may require basic carpentry skills. A licensed electrician is still recommended for the 230V electrical hookup. What is the warranty? This system is backed by MRCOOL’s best-in-class warranty: 7-Year Compressor Warranty 5-Year Parts Warranty Recommended BTU By Room Size BTU Capacity Recommended Room Size (Sq. Ft.) 9,000 BTU 151–350 sq. ft. 12,000 BTU 350–500 sq. ft. 18,000 BTU ← You Are Here 500–800 sq. ft. 24,000 BTU 751–1,000 sq. ft. 36,000 BTU 1,001–1,500 sq. ft. Note: Actual performance may vary depending on room insulation, ceiling height, number of windows, climate zone, and heat-generating appliances.