MRCOOL DIY® 5th Gen 18,000 BTU OuttaSight® Ceiling Cassette Air Handler 230V – Single Zone, Up to 750 Sq. Ft. | DIYCASSETTE18HP-230D25-O

MRCOOL® DIY® 5th Gen 18,000 BTU OuttaSight® Ceiling Cassette Air Handler – Single Zone, 230V The MRCOOL® DIY® 5th Gen 18,000 BTU OuttaSight® Ceiling Cassette is a powerful, flush-mounted indoor unit designed for heating and cooling spaces from 501 to 750 sq. ft. Unlike traditional wall-mount units, this ceiling cassette installs discreetly between standard 16" ceiling joists — ideal for new construction, open-plan spaces, and retrofit projects where wall space is limited. Note: this unit uses a 1/2" suction line — ensure your line set and condenser are compatible before ordering. Why Choose MRCOOL DIY® OuttaSight® Ceiling Cassette? Ceiling-Mounted, Out of Sight — Installs flush between standard 16" ceiling joists (including pre-manufactured I-joists) for a clean, unobtrusive look. Ideal for New Construction & Retrofits — No wall space required. Perfect for open-plan rooms, garages, sunrooms, and commercial spaces. America’s #1 DIY Mini Split — The most trusted DIY mini split brand in the nation, built for quick setup and long-term reliability. QuickConnect® Compatible — Works with MRCOOL pre-charged QuickConnect® line sets for a fast, vacuum-free installation — no special tools needed. Eco-Friendly R-454B Refrigerant — Lower Global Warming Potential (GWP) than R-410A for better efficiency and a reduced environmental footprint. Ultra-Quiet Operation — As low as 26 dB(A) on silent mode — barely audible. High Heating Output — 22,700 BTU heating capacity for reliable warmth even in larger spaces. Advanced Filtration — Improves indoor air quality with built-in filtration; Elevation function allows easy filter access for maintenance. Multiple Wireless Control Options — Control via included remote, 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 — UL Listed, ETL Listed, AHRI Certified. Product Overview 🏠 Zones: 1 📐 Coverage: 501–750 sq. ft. 🔧 Installation: DIY — Ceiling-Mounted, No Professional Required 💨 Airflow Direction: 1-Way ⚡ Voltage: 208-230V 🔇 Noise Level: As low as 26 dB(A) on silent mode ⭐ Certification: UL Listed, ETL Listed, AHRI Certified 🧄 Refrigerant: R-454B ⚠️ Note: Uses 1/2" suction line — verify condenser and line set compatibility before ordering Specifications & Dimensions Capacity & Performance Cooling Capacity 18,800 BTU Heating Capacity 22,700 BTU Coverage Area 501–750 sq. ft. Air Flow – Turbo 400 CFM Air Flow – High 352 CFM Air Flow – Medium 300 CFM Air Flow – Low 207 CFM Air Flow – Silent 207 CFM Noise – Turbo 44.0 dB(A) Noise – High 44.0 dB(A) Noise – Medium 41.5 dB(A) Noise – Low 31.0 dB(A) Noise – Silent 26.0 dB(A) Electrical Requirements Voltage 208-230V Phase 1 Cycle 60 Hz Max Fuse Breaker 15A Min Circuit Ampacity 3A Refrigerant & Piping Refrigerant Type R-454B Liquid Line Size 1/4" Suction Line Size 1/2" Dimensions & Weight Dimensions 50.31" W x 13.19" D x 8.98" H Mount Type Ceiling Weight 45 lbs Features Airflow Direction 1-Way Fan Only Option Yes Quiet Mode Yes Auto Cool Yes WiFi Compatibility Yes App Compatibility Yes Works with iOS Yes Works with Android Yes Remote Control Included Yes Certifications & Warranty Certifications UL Listed, ETL Listed, 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 condenser is compatible with this cassette? This ceiling cassette is compatible with MRCOOL DIY® 5th Gen single-zone or multi-zone condensers rated for 18,000 BTU. Important: this unit uses a 1/2" suction line — ensure your condenser and line set support 1/2" connections before ordering. Does it fit between standard ceiling joists? Yes — the OuttaSight® cassette is designed to fit between standard 16" ceiling joists, including pre-manufactured I-joists, for a flush, concealed installation. Can I install it myself? Yes. Use MRCOOL DIY® pre-charged QuickConnect® line sets for a vacuum-free installation. Ceiling installation may require basic carpentry skills. A licensed electrician is still recommended for the electrical hookup. How quiet is it? Very quiet — as low as 26 dB(A) on silent mode. Even on high, it runs at just 44 dB(A). What is the warranty? This cassette 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.) 6,000 BTU Up to 150 sq. ft. 9,000 BTU 151–350 sq. ft. 12,000 BTU 351–500 sq. ft. 18,000 BTU ← You Are Here 501–750 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.