If you've been researching ductless mini splits, you've probably come across the MRCOOL DIY® series — and for good reason. It's one of the only mini split systems on the market that a homeowner can install without a licensed HVAC technician. No special tools, no refrigerant certification, no contractor markup.
But is it right for you? This guide covers everything you need to know before you buy.
What Is a MRCOOL DIY® Mini Split?
MRCOOL DIY® is a ductless heating and cooling system designed specifically for homeowner installation. Unlike traditional mini splits that require a certified technician to handle refrigerant lines, the MRCOOL DIY® comes with pre-charged line sets that simply connect and click into place.
That means you can go from unboxing to cool air in a single weekend — no HVAC license required.
How Does It Work?
A mini split system has two main components:
- The outdoor condenser — sits outside your home and handles the refrigeration cycle
- The indoor air handler — mounts on your wall and delivers conditioned air into the room
The two units connect via a pre-charged line set (included with MRCOOL DIY® Complete Systems) that carries refrigerant between them. The system runs on electricity and can both heat and cool — making it a true year-round comfort solution.
What Sizes Are Available?
MRCOOL DIY® systems are measured in BTUs, which determines how much space they can effectively heat or cool:
- 9,000 BTU — ideal for rooms up to 350 sq ft (bedroom, home office, studio)
- 12,000 BTU — ideal for rooms up to 550 sq ft (living room, master bedroom)
- 18,000 BTU — ideal for spaces up to 750 sq ft (open floor plan, large living area)
- 24,000 BTU — ideal for spaces up to 1,000 sq ft (large rooms, garage, workshop)
Not sure which size you need? A general rule of thumb is 25 BTU per square foot for standard ceiling heights.
MRCOOL DIY® vs. Traditional Mini Splits: What's the Difference?
| Feature | MRCOOL DIY® | Traditional Mini Split |
|---|---|---|
| Homeowner installation | ✅ Yes | ❌ No |
| Pre-charged line set | ✅ Included | ❌ No |
| HVAC technician required | ❌ No | ✅ Yes |
| WiFi & app control | ✅ Built-in | Varies |
| Heating & cooling | ✅ Both | Varies |
| Typical install time | 4-8 hours | 1-2 days + scheduling |
5th Generation vs. 4th Generation: Which Should You Buy?
MRCOOL recently released their 5th Generation DIY® system with several upgrades over the 4th Gen:
- Higher efficiency ratings (better SEER2 scores = lower energy bills)
- Improved cold weather performance — heats effectively down to -13°F
- Enhanced WiFi connectivity with the MRCOOL SmartHVAC app
- Quieter operation at low fan speeds
If you're buying new, go with the 5th Generation — the efficiency gains alone will pay for the price difference over time.
Is MRCOOL DIY® Worth It?
For most homeowners, absolutely yes. Here's why:
- Save $500-$2,000+ on installation costs by doing it yourself
- No scheduling headaches — install on your timeline
- WiFi control from anywhere via the MRCOOL app
- Heats and cools — replaces both your AC and space heater
- Energy efficient — most models qualify for federal tax credits
What's Included in a MRCOOL DIY® Complete System?
When you purchase a Complete System from Charming Dwelling, you get everything you need in one box:
- ✅ Outdoor condenser unit
- ✅ Indoor air handler
- ✅ Pre-charged line set (25 ft)
- ✅ Mounting bracket
- ✅ Wiring harness
- ✅ Remote control
- ✅ WiFi module
All you need to supply is a dedicated electrical circuit and basic hand tools.
Ready to Buy? Shop MRCOOL DIY® at Charming Dwelling
We carry the full MRCOOL DIY® lineup — from 9,000 BTU single-zone systems to 24,000 BTU powerhouses. Every system ships fast with free shipping and comes backed by MRCOOL's manufacturer warranty.
Shop MRCOOL DIY® Mini Splits →
Questions? We're here to help you find the right system for your space.
