Mini-Split Installation Glossary

Plain-English explainers for the technical terms, rebates, regulations, and acronyms that show up when you shop for Mini-Split Installation systems and services. Each entry links the underlying source, lists the numbers that matter, and points to related concepts.

Ceiling Cassette
A recessed, ceiling-mounted indoor unit — the discreet alternative to a wall head when there's a drop ceiling or no wall to spare.
Hyper-Heat / Cold-Climate Heat Pump
Ductless heat pumps engineered to hold heating capacity near and below freezing, where a standard mini-split fades.
Concealed-Duct (Ducted Mini-Split Air Handler)
A hidden indoor unit that feeds short duct runs — ductless efficiency for several rooms without a head in each one.
EPA Section 608 Certification
The federal license to handle refrigerant — the credential a mini-split installer legally needs to charge your system.
HSPF2 (Heating Seasonal Performance Factor 2)
The heating-efficiency score for a mini-split heat pump — the number that matters most if you'll heat with it, not just cool.
Inverter (Variable-Speed Compressor)
The variable-speed technology behind nearly every mini-split — it ramps up and down instead of slamming on and off.
Line Set (Refrigerant Lines)
The pair of insulated copper lines linking the outdoor and indoor units — its length, charge, and flares decide how the system runs.
Manual J (Load Calculation)
The ACCA standard for sizing a system to the home's actual load — the step that decides whether a mini-split performs as rated.
Multi-Zone vs. Single-Zone
One outdoor unit running several indoor heads, versus one-to-one — the choice drives both flexibility and efficiency.
SEER2 (Seasonal Energy Efficiency Ratio 2)
The cooling-efficiency score for a mini-split — ductless inverters run far above the federal minimum, which is where the savings live.
VRF / VRV (Variable Refrigerant Flow)
The commercial-scale cousin of the residential multi-zone mini-split — many indoor units on one refrigerant network.
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