Mini Split for 900 Sq Ft: Size, Cost & Systems
At the standard 20 BTU per square foot baseline, a 900 sq ft space needs about 18,000 BTU of cooling, which lands in the 18,000 BTU class on the standard sizing chart. Our dataset holds 13 verified system(s) here, 10 with first-hand prices from $999.99 to $4,214.25; the cheapest is the Senville LETO 18k, and 3 of them are true DIY (pre-charged line sets). Of these, 3 state a coverage range that explicitly includes 900 sq ft.
Computed from our dataset
- 13 system(s) from our verified dataset appear on this page; 10 carry a verified USD price.
- Price range: $999.99 to $4,214.25 (verified 2026-11-04).
- Cheapest: Senville LETO 18k at $999.99 (Senville).
- Highest SEER2: Senville AURA 18k Dual-Zone at 25 SEER2.
- Best heating rating: Senville AURA 18k Dual-Zone, rated to -22°F.
- True DIY in this list: 3 system(s) with factory pre-charged line sets.
| System | Zones | BTU | Coverage | SEER2 | Heats to | Install | Price | |
|---|---|---|---|---|---|---|---|---|
| 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 |
| 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 |
| Pioneer Quantum Ultra 18k Dual-Zone (2x 9k) Quantum Ultra YN020GLFI20M2D | 2 | 18,000 | — | — | -13°F | Pro / flare | $2,094 at Pioneer Mini Split | Check price |
| MRCOOL DIY 5th Gen 2-Zone 18k (6+6) DIY-MULTI3-18HP230 | 2 | 18,000 | — | 23.9 | -13°F | Pro / flare | $2,469$2,715.90 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 |
| Daikin Aurora 18k FTXV18AVJU9 / RXT18AVJU9 | 1 | 18,000 | — | 21 | -13°F | Pro / flare | $3,932 at Alpine Home Air | Check price |
| Daikin Aurora MXT 18k 2-Zone (7+15) 2MXT18AVJU9 | 2 | 18,000 | — | 21 | — | Pro / flare | $3,956 at HVACDirect | Check price at HVACDirect |
| LG Multi F RED 18k 2-Zone (12+9) KUMXA181A | 2 | 18,000 | 900-1,050 sq ft | 20 | — | Pro / flare | $4,076 at HVACDirect | Check price at HVACDirect |
| 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 |
| Senville AURA 18k Dual-Zone SENA-18HF/D | 2 | 18,000 | 750-1,250 sq ft | 25 | -22°F | Pro / flare | Not verified no USD price found | Specs source |
| Cooper & Hunter Mia NG 18k CH-NG18MIA230VO | 1 | 18,000 | — | — | -13°F | Pro / flare | Not verified no USD price found | Specs source |
| TOSOT Muse 18k (prior generation) TST-SU-MUSE-18K230 | 1 | 18,000 | — | — | -13°F | True DIY | Not verified no USD price found | Specs source |
Buying notes
- The 20 BTU/sq ft baseline assumes 8-9 ft ceilings, average insulation, and a moderate climate; the sizing guide lists the adjustments (sunrooms run 30-35 BTU/sq ft, kitchens add ~4,000 BTU).
- Oversizing an inverter system slightly is low-risk (it modulates down); oversizing a lot short-cycles and leaves humidity behind.
- If this space is one room of several, compare a multi-zone system before buying a big single-zone - one condenser can serve several handlers.