Best Mini-Split for ADU (2026) — Studio + 1BR ADU Picks
ADUs (accessory dwelling units) typically need 18-24K BTU multi-zone or single-zone depending on layout. Pre-permit ADU plans should include the unit spec — it affects electrical sizing.
ADUs (granny flats, casitas, garage conversions) need their own HVAC — they can't share with the main house. Mini-splits dominate this market because they fit any layout, install with minimal duct work, and meet California Title 24 efficiency requirements.
Quick Comparison
| Pick | Best For | Approx Price |
|---|---|---|
| Best Studio ADU | Mr Cool DIY 5th Gen 12K BTU 22 SEER2 | $1,599-$1,899 |
| Best 1BR ADU Single-Zone | Mr Cool EasyPro 5th Gen 18K BTU 24 SEER2 | $2,199-$2,499 |
| Best 1BR/2BR Multi-Zone | Mr Cool Multi-Zone 27K BTU 2-Zone | $3,200-$3,800 |
Our Picks
ADU Sizing by Type
Studio ADU (under 500 sq ft): 12,000 BTU single zone is plenty.
Studio ADU with kitchen (500-700 sq ft): 18,000 BTU single zone.
1BR ADU (700-900 sq ft): 18,000-24,000 BTU single zone OR multi-zone with 1 living-area head + 1 bedroom head.
2BR ADU (900+ sq ft): multi-zone with 2-3 indoor heads.
Permit + Title 24 Requirements
Every California ADU requires HEERS (Home Energy Rating System) compliance. Mini-splits with 20+ SEER2 easily exceed Title 24 requirements. The Mr Cool EasyPro line at 24 SEER2 specifically markets as Title 24-compliant for ADU permits.
Submit the mini-split spec with the ADU plans — surveyor and city inspector both verify HVAC at permit pull and final inspection.
Electrical Considerations
ADU electrical typically runs from the main house's panel. 240V dedicated circuit for the mini-split (15-30A depending on size). Most ADU builds also need a sub-panel for the ADU itself — handled during construction, not retrofit.
Where to Buy
For the unit, we recommend HVACzar — they verify Title 24 compliance specs at point of sale and offer contractor wholesale for HVAC pros.
Need help with this in California?
Zomg The Handyman provides professional hvac mini-split installation across all of California. Insured, background-checked, 4.9★ rated. Same-day available.
Get a Mini-Split Quote →Frequently Asked Questions
What size for a studio ADU?
Under 500 sq ft: 12,000 BTU. With kitchen: 18,000 BTU.
Multi-zone or single-zone for a 1BR ADU?
Single-zone if you want simplicity. Multi-zone if you want independent bedroom control. Both work for permits.
Title 24 compliant?
Yes — Mr Cool 22 SEER2+ models exceed California Title 24 requirements with margin.
Where do I buy?
HVACzar (hvaczar.com) for Mr Cool lineup with Title 24 compliance verification.
How much for ADU install?
$799-$1,299 single-zone. $1,499-$3,499 multi-zone. Permit-required HVAC final inspection included.
Our service areas: MrCool Installation in Los Angeles · MrCool Installation in San Diego · MrCool Installation in Irvine
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