What's in the box
- 1 × MRCOOL® DIY® 9K 5th Gen Condenser — DIY-09-HP-C-115D25-O
- 1 × MRCOOL® DIY® 9K 5th Gen Air Handler — DIY-09-HP-WMAH-115D25-O
- 1 × 25 ft Quick Connect® Line Set, 1/4" × 3/8"
- 1 × MRCOOL® Remote Control
- 1 × DIYPRO® Cable
- Installation documentation
DIY-friendly installation.
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Designed for simplified installation using MRCOOL® Quick Connect® technology.
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Electrical requirements, permits, and building codes may vary by location.
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Professional electrical work may be required depending on local regulations, system placement, and installation conditions.
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Always review the product installation manual before purchase and installation.
- Base Parts Warranty: 5 Years
- Base Compressor Warranty: 7 Years
- Eligible for the MRCOOL® Care Program
Please refer to the product warranty documentation for full warranty terms, registration requirements, and coverage details.
- Free U.S. curbside delivery within the Lower 48 States on qualifying orders
- Orders ship from U.S. warehouse locations
- Delivery times may vary by destination, product availability, and carrier scheduling
- Returns are accepted within 30 days for unused, uninstalled products that meet return eligibility requirements
- Approved returns may be subject to a restocking fee
Manuals & documents
MODEL: DIY-09-HP-WM-115D25-O
Small Room Comfort Made Simple.
Need a smarter way to heat and cool a bedroom, home office, guest room, or smaller living space without the cost and complexity of traditional HVAC installation?
The MRCOOL® DIY® 5th Gen 9K BTU Mini Split System is designed to deliver efficient year-round comfort for spaces around 250–400 sq ft, making it a strong choice for smaller rooms that are too hot, too cold, or difficult to keep comfortable.
This complete single-zone system pairs a MRCOOL® DIY® 5th Gen 9K BTU wall-mounted air handler with a matching 115V condenser and included 25 ft Quick Connect® line set, helping simplify installation without traditional vacuuming.
With 23.6 SEER2 efficiency, DC inverter technology, R-454B refrigerant, quiet operation, and smart control through the SmartHVAC® app, this system gives homeowners reliable heating and cooling with greater everyday control.
Use the included remote, your smartphone, Amazon Alexa, or Google Assistant to adjust comfort with ease, while Follow Me® technology helps sense temperature around the remote for comfort where you are.
Dry Mode helps reduce humidity, Quiet Mode supports peaceful operation, and the Gold Fin® condenser coating helps protect against corrosion for long-term reliability.
Easy comfort. Smart control. Built for smaller spaces.
Why You’ll Love It
✅ Ideal for spaces around 250–400 sq ft
✅ High-efficiency 23.6 SEER2 performance
✅ Complete single-zone mini split system
✅ Includes matching air handler and condenser
✅ Includes 25 ft Quick Connect® line set
✅ 115V electrical configuration
✅ SmartHVAC® app compatibility
✅ Works with Amazon Alexa and Google Assistant
✅ Quiet indoor operation as low as 18 dBA
✅ 7-Year Compressor / 5-Year Parts Base Warranty
Best For
Bedrooms • Home Offices • Guest Rooms • Small Living Areas • Studios • Small Additions • Quiet Comfort Zones • DIY Mini-Split Installations
Need More Heating & Cooling Power?
If your space is larger, has high ceilings, large windows, poor insulation, or stronger heating and cooling demands, a larger system may be a better fit.
Explore larger MRCOOL® DIY options:
12K BTU Mini-Split Systems
18K BTU Mini-Split Systems
24K BTU Mini-Split Systems
36K BTU Mini-Split Systems
Multi-Zone Mini-Split Systems
| Specification | Details |
|---|---|
| Coverage Area | Up to 400 sq ft |
| Cooling Capacity | 9,000 BTU |
| Heating Capacity | 10,000 BTU |
| Voltage | 115V |
| Zone Type | Single Zone |
| SEER2 | 23.6 |
| EER2 | 14 |
| HSPF2-4 | 11.5 |
| HSPF2-5 | 8.6 |
| Indoor Sound Level | 18–43 dB(A) |
| Outdoor Sound Level | 54 dB(A) |
| WiFi Compatible | Yes |
| Voice Assistant | Alexa & Google Assistant |
| Inverter Technology | DC Inverter |
| Refrigerant | R-454B |
| Line Set Length | 25 ft |
| Max Line Set Length | 82 ft |
| Line Sizes | 1/4" Liquid / 3/8" Suction |
| Compressor Type | Rotary |
| Certifications | AHRI, UL, ETL, Energy Star® |
| Warranty | 7-Year Compressor / 5-Year Parts |
Questions, answered
Everything homeowners ask before buying a MRCOOL® system.
Installation
Do I need an HVAC technician to install this?
No. MRCOOL® DIY systems are designed for homeowner installation. The pre-charged Quick Connect® line set means there's no refrigerant handling, no vacuum pump, and no special tools or license required.
How long does installation take?
Most single-zone systems go in within a few hours: mount the indoor air handler, set the outdoor condenser, connect the pre-charged line set, and power it on.
Do I need an electrician?
The system needs a dedicated circuit. Most homeowners have a licensed electrician add the breaker and disconnect — everything else you can do yourself.
Sizing & compatibility
What BTU size do I need?
As a rule of thumb: up to 400 sq ft → 9–12K BTU, 400–600 sq ft → 12–18K, 600–1,000 sq ft → 18–24K. Use the room-size guide above and factor in insulation, ceiling height and sun exposure.
Will it heat in winter?
Yes — these are heat pumps, so they heat and cool. Many MRCOOL® systems keep heating in sub-freezing temperatures; check each model's spec sheet for its low-temperature heating range.
115V or 230V — which do I need?
9K–12K units are usually 115V (standard outlet circuit); 18K and larger are typically 230V. The voltage is shown in the product options and specifications.
Warranty & support
What warranty is included?
MRCOOL® systems carry manufacturer warranty coverage — typically 5–10 years on major components when you register your system after installation.
How do I get help choosing or installing?
Email support@coolheatdirect.com — our U.S. team replies within one business day with sizing, voltage and compatibility help.
Shipping & returns
How fast does it ship?
Most products ship in 3–5 business days with free curbside delivery in the continental U.S. The freight carrier calls to schedule your delivery.
Can I return it?
Returns are accepted within 30 days on new, unopened items in original packaging. A restocking fee may apply to HVAC equipment — we always confirm before issuing a return authorization.
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