If you want whole-home cooling without the noise and inefficiency of window units, a split-system air conditioner is the standard play. It uses an indoor unit (coil + blower/air handler) and an outdoor unit (condenser + compressor) connected by refrigerant lines. The outdoor unit dumps the heat; the indoor unit delivers cooled, dehumidified air through your ducts. Simple, quiet, and easy to service.
How a Split System Works
- The compressor pressurizes the refrigerant outside.
- The condenser coil rejects heat to outdoor air.
- Liquid refrigerant expands, gets cold, and flows to the indoor evaporator coil.
- Your blower/air handler moves room air across that coil, cooling and dehumidifying it, then pushes it through ducts.
That’s the loop, on repeat, all summer long. (This is the core split-system cycle.)
What You’ll See When Shopping
Modern split AC category pages let you sort by brand, tonnage, SEER2, refrigerant, and configuration. You’ll also notice many current models using R-32 and SEER2 ratings like 14.3–16.2 SEER2 plus options such as multi-positional air handlers (upflow/downflow/horizontal) and wall-mount indoor cabinets for tight spaces.
SEER2 (the 2023 reality)
As of January 1, 2023, federal rules require new efficiency metrics—SEER2/EER2/HSPF2—with tougher test procedures (Appendix M1). Minimums vary by U.S. region and equipment class, so make sure your chosen system is compliant for your install location. Higher SEER2 = lower cooling energy use.
R-32 (why so many models use it now)
R-32 is popular because it transfers heat efficiently and carries a much lower global-warming potential than older blends like R-410A—one reason you’ll see “R-32” as a filter on many retail pages. In practice, that can help trim power use while reducing environmental impact.
Key Specs That Actually Matter
- Capacity (Tonnage): Match tonnage to a load calculation (Manual J). Oversizing causes short-cycling and clammy rooms; undersizing runs constantly.
- SEER2: Aim higher if you live with long, hot seasons or high electricity rates. Confirm regional minimums.
- Refrigerant: R-32 is increasingly common; it pairs efficiency with lower GWP vs. R-410A.
- Air Handler Configuration: Multi-positional units make attic, closet, or crawlspace installs easier (upflow/downflow/horizontal).
- Controls: From basic thermostats to smart stats and app control; a good thermostat schedule can save as much as a hardware upgrade over time.
- Warranty & Serviceability: Look for clear parts warranties and easy access to coils, filters, and boards.
Sizing: Quick Framework (so you don’t guess)
- Load calc first. Square-foot rules are just a starting point; factor insulation, windows/orientation, ceiling height, and airtightness.
- Ducts decide comfort. If static pressure is high or ducts are leaky/undersized, fix that or pick an air handler that can actually move the air.
- Climate matters. High humidity or west-facing glass may justify a slight capacity bump—but not a full ton jump.
Install Basics (what good pros do)
- Line-set & charge: Properly sized line set, deep vacuum, and charge verification.
- Airflow: Set blower speed for correct CFM/ton; confirm static pressure.
- Condensate: Trap, slope, and a float safety switch.
- Commissioning: Verify temperature split, subcool/superheat, controls, and thermostat staging.
Maintenance (keep efficiency, keep comfort)
- Replace/clean filters (every 1–3 months).
- Keep outdoor coil clean and vegetative clearance open.
- Annual service: electrical checks, coil cleanliness, drain, and charge confirmation.
Quick Picks by Scenario
- Tight closet or mixed orientations: Choose a multi-positional air handler that can go upflow/downflow/horizontal.
- Long cooling season or high kWh rates: Target 15.2 SEER2+ within budget.
- Lower footprint refrigerant: Prioritize R-32 models.
FAQs
What’s the difference between a split system and a package unit?
A package unit puts everything outside in one cabinet; a split system divides indoor and outdoor components and connects them with refrigerant lines.
Is a split system the same as a mini-split?
Both are “split,” but a ducted split AC uses existing ducts and an air handler. A ductless mini-split uses wall/ceiling cassettes with no ducts. (Same physics, different delivery.)
Do I need R-32?
You don’t “need” it, but R-32 offers efficiency and a lower GWP than R-410A. It’s becoming standard in many lines.
