A mini split is the best HVAC solution for a tiny home — no ductwork, no central system, just a wall-mount indoor unit and a small outdoor compressor. In Oklahoma's climate (110°F summers, hard freezes in winter), you need real heating and cooling capacity. Here's how to get it right.
How to Size a Mini Split for a Tiny Home
Mini splits are rated in BTU (British Thermal Units). The general rule for a well-insulated tiny home in a hot climate like Oklahoma:
| Cabin Size | Recommended BTU | Tonnage |
|---|---|---|
| Up to 150 sq ft | 9,000 BTU | 0.75 ton |
| 150–250 sq ft | 9,000–12,000 BTU | 0.75–1 ton |
| 250–400 sq ft | 12,000–18,000 BTU | 1–1.5 ton |
| 400–600 sq ft | 18,000–24,000 BTU | 1.5–2 ton |
Oklahoma climate adjustment: Add 10–15% to the above for Oklahoma's extreme summer heat. A 150 sq ft well-insulated cabin in OKC should run a 9,000–12,000 BTU unit to handle 110°F days comfortably.
Best Mini Splits for Tiny Homes (Amazon)
🏆 Best Overall: Pioneer WYS009GMFI22RL — 9,000 BTU DIY Mini Split
Pioneer's DIY mini split is the most popular ductless unit on Amazon for tiny home builds. The "WYS" line is designed for homeowner installation — pre-charged refrigerant lines, included mounting hardware, and clear instructions. A licensed HVAC tech still needs to handle the refrigerant line connection in most states, but everything else is DIY. Runs down to 5°F outdoor temperature — handles Oklahoma ice storms.
- 9,000 BTU — right-sized for 150–200 sq ft tiny homes
- DIY-friendly installation design
- Works as heat pump down to 5°F
- 22 SEER — very efficient, low operating cost
- Includes WiFi control via app
- 5-year compressor warranty
Best Budget: DELLA 9,000 BTU Mini Split — 19 SEER
DELLA's mini split consistently offers the lowest price per BTU on Amazon while maintaining solid reviews. Less efficient than Pioneer (19 vs 22 SEER) but for a tiny home that's a $20–40/year difference in electricity cost. Good choice if upfront cost matters more than maximum efficiency. Heat pump capable down to 14°F.
- 9,000 BTU at the lowest price point
- 19 SEER — still above minimum efficiency standard
- Heat pump mode to 14°F
- Includes installation kit
- Remote control and timer included
Best Performance: Senville LETO Series — 9,000 BTU
Senville's LETO series is the step up from Pioneer for tiny home builds where you want maximum reliability. Quieter indoor unit (26 dBA — nearly silent), works to -22°F outdoor temperature (exceptional for Oklahoma ice storms), and includes a built-in air purifier. If you're building a year-round full-time tiny home, the Senville is worth the extra $100 over Pioneer.
- Works to -22°F — handles any Oklahoma winter
- 26 dBA indoor noise level — nearly silent
- Built-in air purifier filter
- 21 SEER efficiency rating
- Includes WiFi module
- ETL certified for US installation
Installation Overview
What you can DIY
- Mount the indoor wall unit and outdoor compressor bracket
- Run the line set through the wall (3" hole)
- Connect electrical wiring (with proper permits)
- Mount and connect the outdoor unit
What requires a licensed HVAC tech
- Connecting and pressurizing refrigerant lines (in most states)
- Vacuuming the line set before charging
- Any refrigerant top-off or leak repair
Budget $150–$300 for an HVAC tech to handle the refrigerant connection on an otherwise DIY install. Total installed cost for a Pioneer 9,000 BTU: $850–$1,200.
Electrical requirements
A 9,000 BTU mini split typically requires a dedicated 15A/240V circuit. For an off-grid tiny home, this means your power station needs 240V output — check before buying. Most portable power stations output 110V only. The Bluetti AC200P and EcoFlow DELTA Pro have 240V output and can run a mini split briefly.
See also: tiny home insulation guide and year-round living in a tiny home for the complete comfort picture.