Safety note: Refrigerant and electrical work have legal and safety requirements. Per the EPA, connecting or disconnecting pre-charged refrigerant lines on a mini-split requires Section 608 technician certification. Follow the installation manual, the National Electrical Code and your local code, and use a licensed electrician where your jurisdiction requires one. This is general information, not professional advice.
Heat pumps come in two basic layouts: ducted, where a central air handler pushes air through ducts, and ductless, where small indoor heads sit in the rooms they serve. Here’s how the trade-offs line up, using DOE’s Building America guide and ENERGY STAR.
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ENERGY STAR’s rule of thumb
Mini-splits are “specifically designed for homes or sections of homes that do not have ductwork. If your home does have existing ductwork, a ducted ASHP system may be the right system for you” (ENERGY STAR). A ducted heat pump “can use pre-existing ductwork” and in most zones can be installed as “a drop-in replacement when either a central air conditioner or a furnace needs replacement” (ENERGY STAR).
Trade-offs
| Factor | Ducted | Ductless |
|---|---|---|
| Duct losses | Losses “can account for more than 30% of heating and cooling energy consumption if ducts are located in an unconditioned area” (BASC) | Eliminated, because indoor units sit inside the conditioned space (BASC) |
| Fan energy | Must push air through ducts | “Less fan energy is required” (BASC) |
| Zoning | One thermostat unless zoned | Each head runs independently (BASC) |
| Room coverage | Supply registers in every room | Rooms without a head may be uncomfortable; small heads can be oversized for small rooms (BASC) |
| Filtration | Ask about the MERV rating of compatible filters (BASC) | Standard washable mesh filters capture fine particles poorly (BASC) |
| Appearance | Hidden; only registers show | Visible wall heads, unless ceiling cassettes or concealed units |
| Compressor | Single-speed is more common in traditional ducted units (BASC) | Generally inverter, variable speed (BASC) |
Which fits your home
- Existing ducts in good shape, inside the conditioned space: a ducted heat pump is the simplest swap.
- Ducts in a vented attic or crawlspace: ductless avoids the duct losses BASC describes; a ducted system avoids them when the air handler and ducts are inside the conditioned space.
- No ducts (radiators, baseboard): ductless, per ENERGY STAR.
- Additions, finished attics, basements or garages: BASC calls ductless “an excellent choice” for these (BASC). See mini-split for a garage and for a basement.
- Comparing with a whole-home ducted heat pump: see mini-split vs central heat pump.
Ratings: what to compare
ENERGY STAR sets different cold-climate thresholds by layout: non-ducted split systems need at least 8.5 HSPF2, ducted split systems at least 8.1 HSPF2, both with at least 15.2 SEER2, plus low-temperature requirements: COP at 5°F of at least 1.75 and 5°F capacity at least 70% of 47°F capacity (ENERGY STAR). Check the AHRI certificate for the exact indoor/outdoor match; see how to read an AHRI certificate.
Prices: we don’t list prices because they vary by region and change often (site policy, Oct 13, 2026). Use the check-current-price links and get local quotes for installation.
FAQ
Is ductless always more efficient? Not always, but it avoids duct losses and has lower fan energy (BASC). A well-sealed ducted system inside the envelope narrows the gap.
Can I mix both? Yes; you can keep a ducted system and add ductless heads where ductwork is hard to extend. ENERGY STAR notes mini-splits can “supplement your existing HVAC system” (ENERGY STAR).