Is a mini-split cheaper than window units or central air over its life?

Before you decide

• Heating: a mini-split is a heat pump, so it can also heat. This page counts cooling only. If it would replace some of your oil, propane or gas heat, use the heat pump calculator, where heating savings are counted.
• Money only: this page does not count noise, looks, security, a blocked window, putting units in and out each year, or that a window unit cools one room.
• Different jobs: central air cools every room on its ducts, so it is priced for the whole home. If you would run it in fewer rooms, enter that area for the whole home. If you would use fewer rooms with the other two, they use less power.
• Hours and ratings: the hours come from New York's utility manual for a typical house with attic ducts and are the same for all three options. Window units are often run only in occupied rooms, which the space you enter handles. A label rating is a lab figure, and the manual finds that mini-splits fall short of it more than other equipment does (see the field check).
• Already have central air that works? This page prices all three as new. A system you own is a sunk cost. To compare keeping it, set its price to 0, its rating to the label and its life to at least the years compared. Repairs and breakdown risk are not modeled.
• Rebates: the federal credit 25C ended for equipment installed after 2025-12-31 (IRS, page reviewed 2026-04-28). New York's Clean Heat rebates are for heat pumps used for heating, and amounts vary by utility, so check before you rely on one.
• Renting or in a condo? Check your lease or building rules before you plan on window units or a mini-split.

How this estimates

Power. Cooling capacity is 20 Btu an hour for each sq ft. Kilowatts at full power are that capacity divided by the rating and by 1,000, because every rating here is Btu per watt-hour. Power a year is those kilowatts times the full-power hours. Window units and the mini-split use the space you enter and central air uses the whole home. The hours already include typical attic duct losses and some oversizing, so they are slightly unkind to window units and mini-splits, which have no ducts.

Buying. Window units cost the unit price times the rooms. The mini-split costs the first price plus the added price for each room after the first, less the rebate (counted up to its price). Central air costs its price, plus new ducts when the home has none. Equipment is bought again at its full price in year life plus 1, then every life after that, while the year is inside the period. New ducts are paid once.

Totals. Each year's power is the first year's power times the price rise to the power of the years gone. Upkeep stays flat. The total is the price now plus later purchases plus power plus upkeep. It is not discounted and leaves out the life left in equipment.

Break-even hours. With no cooling, each option costs only its price, purchases and upkeep, and each full-power hour adds a fixed amount over the years. The break-even is where two totals meet.

What-ifs. Flat prices set the price rise to 0. Life left credits what remains of the last purchase in a straight line. The field check swaps the mini-split's label rating for the manual's estimate, which comes from heat pump data and has no counterpart for window units or central air. It is a stress test, not the main answer.

What this leaves out

Heating, financing, a discount rate, tax, resale value, sales tax, panel or wiring work, permits, noise and comfort, the size of each unit, and what a repair or a breakdown would cost.

Not verified

Every energy.gov Energy Saver page and every NYSERDA page we tried failed to open (404 and 403), so DOE's own lifespan, duct and efficiency statements and any NYSERDA rebate amount are unverified and not used. Con Edison's rebate list could not be read, so no utility rebate for window units was confirmed. HomeGuide, Best Buy, Lowe's and Consumer Reports did not open. The 2023 federal rule behind the 2026 window unit standard is second-hand, and ENERGY STAR's efficiency thresholds could not be read. Version 14 of the utilities' manual (effective 2027-01-01) was not opened. No screen reader has been run on this page.

Sources and date checked

The table below gives each default's source, status and the date read or tried. These are examples, not quotes. Fees, rebates and rules change; check your bill and your quotes.

An estimate from the numbers you typed. Not an offer, not financial advice. This page has no referral, store or affiliate links, and it does not rank or recommend any brand.