Best Mini Split for a Home Addition
Additions are the classic mini split project - no duct extension, no furnace upsizing, one room on its own system. Most land at 12k-18k. Our dataset holds 19 verified system(s) here, 19 with first-hand prices from $659 to $4,214.25; the cheapest is the Klimaire KSIE 12k, and 4 of them are true DIY (pre-charged line sets).
Computed from our dataset
- 19 system(s) from our verified dataset appear on this page.
- Price range: $659 to $4,214.25 (verified 2026-11-04).
- Cheapest: Klimaire KSIE 12k at $659 (Heat & Cool).
- Highest SEER2: Senville AURA 12k at 25.4 SEER2.
- Best heating rating: Senville AURA 12k, rated to -22°F.
- True DIY in this list: 4 system(s) with factory pre-charged line sets.
| System | Zones | BTU | Coverage | SEER2 | Heats to | Install | Price | |
|---|---|---|---|---|---|---|---|---|
| Klimaire KSIE 12k KSIE012-H120-O / KSIE012-H120-IW-2 | 1 | 12,000 | 550 sq ft | — | 5°F | Pro / flare | $659$969 at Heat & Cool | Check price |
| Cooper & Hunter MIA 12k CH-RLS12MIA-230VI / CH-RLS12MIA-230VO | 1 | 12,000 | up to ~550 sq ft | 21.3 | 5°F | Pro / flare | $729.57$860.89 at MiniSplitsForLess | Check price |
| Senville LETO 12k SENL-12CD | 1 | 12,000 | 450-750 sq ft | 21.2 | 5°F | Pro / flare | $799.99 at Senville | Check price |
| TOSOT Cosmo 12k Cosmo 12k (230V) | 1 | 12,000 | 650 sq ft | 19 | -13°F | Pro / flare | $809.99 at TOSOT Direct | Check price |
| Pioneer Diamante Pro 12k WYT012ALSI20RL | 1 | 12,000 | 350-500 sq ft | 20 | -4°F | Pro / flare | $928$1,329 at Pioneer Mini Split | Check price |
| LG Standard 12k KSSAE121A | 1 | 12,000 | up to 550 sq ft | 18 | — | Pro / flare | $929 at HVACDirect | Check price at HVACDirect |
| MRCOOL Advantage 5th Gen 12k (pro install) A-12-HP-115D-O | 1 | 12,000 | up to 550 sq ft | 21.2 | 5°F | Pro / flare | $937 at HVACDirect | Check price at HVACDirect |
| Senville LETO 18k SENL-18CD | 1 | 18,000 | 700-1,000 sq ft | 19.2 | 5°F | Pro / flare | $999.99 at Senville | Check price |
| Pioneer Diamante Pro 18k WYT018GLSI20RL | 1 | 18,000 | 500-750 sq ft | 21 | -4°F | Pro / flare | $1,178$1,679 at Pioneer Mini Split | Check price |
| Senville AURA 12k SENA-12HF | 1 | 12,000 | — | 25.4 | -22°F | Pro / flare | $1,399.99 at Sylvane | Check price |
| Senville AURA 12k Ceiling Cassette SENA-12HF-IC | 1 | 12,000 | — | 22.2 | -22°F | Pro / flare | $1,399.99 at Senville | Check price |
| MRCOOL DIY Easy Pro 12k EZPRO-12-HP-11516D-O | 1 | 12,000 | up to 550 sq ft | 19.5 | -13°F | True DIY | $1,649 at HVACDirect | Check price at HVACDirect |
| MRCOOL DIY Easy Pro 18k EZPRO-18-HP-23016D-O | 1 | 18,000 | up to 800 sq ft | 20 | -13°F | True DIY | $1,827 at HVACDirect | Check price at HVACDirect |
| Daikin Oterra 12k FTXF12BVJU9 / RXF12BVJU9 | 1 | 12,000 | 400-600 sq ft | 21 | 5°F | Pro / flare | $1,940$2,294.40 at HVACDirect | Check price at HVACDirect |
| MRCOOL DIY 5th Gen 12k DIY-12-HP-WM-115D25-O | 1 | 12,000 | up to 550 sq ft | 22 | -13°F | True DIY | $2,359 at HVACDirect | Check price at HVACDirect |
| MRCOOL DIY 5th Gen 18k DIY-18-HP-WM-230D25-O | 1 | 18,000 | up to 800 sq ft | 21.5 | -13°F | True DIY | $2,909 at HVACDirect | Check price at HVACDirect |
| Mitsubishi EX-Series Hyper-Heat 12k SUZ-AA12NLHZ / MSZ-EX12NLS | 1 | 12,000 | ~400-600 sq ft | 17.6 | — | Pro / flare | $3,792 at HVACDirect | Check price at HVACDirect |
| Daikin Aurora 18k FTXV18AVJU9 / RXT18AVJU9 | 1 | 18,000 | — | 21 | -13°F | Pro / flare | $3,932 at Alpine Home Air | Check price |
| Mitsubishi EX-Series Hyper-Heat 18k SUZ-AA18NLHZ / MSZ-EX18NLS | 1 | 18,000 | up to ~800 sq ft | 17.5 | -13°F | Pro / flare | $4,214.25 at HVACDirect | Check price at HVACDirect |
Buying notes
- Match the system to the space's worst season: cooling load sets the class, the heating rating decides whether it is a year-round tool.
- Every system here is a verified, priced single-zone (or, for ADUs, a small multi-zone) - class pages list the full field including unpriced systems.