Mini split cost dataset

Line items

Lines marked conditional only apply to some configurations. Note that the single zone and multi zone condensers are alternatives, never both: a multi zone unit costs meaningfully more per BTU, which is why a second room costs more than half of a second system.

Cooling capacity by room area

Values from the table published by ENERGY STAR for room air conditioners, calculated for eight-foot ceilings. Retrieved 2026-08-21. The third column is the nearest capacity that equipment is actually manufactured in, because a unit is not sold in 13,400 BTU and rounding up is what you pay for.

Adjustments

These are the adjustments ENERGY STAR publishes with the table, not additions of ours.

• Heavily shaded: ENERGY STAR: reduce capacity by 10%.
• Normal: No adjustment.
• Very sunny: ENERGY STAR: increase capacity by 10%.
• More than two regular occupants: add 600 BTU for each additional person.
• Kitchen: add 4,000 BTU.

This is a screening estimate, not a load calculation. The professional standard for sizing an installation is an ACCA Manual J, which accounts for insulation, glazing, orientation and infiltration. It is licensed material and is not reproduced here, nor approximated. Expect an installer’s number to differ from this one.

Capacities modelled as available equipment: 6,000 · 9,000 · 12,000 · 15,000 · 18,000 · 24,000 · 30,000 · 36,000 · 42,000 · 48,000 BTU.

The reasoning behind each figure

Written out so that someone who fits these for a living can point at the exact assumption that is wrong. A number with no reasoning behind it cannot be corrected.

Outdoor condenser, single zoneestimated, ±34%

• Priced per thousand BTU of rated capacity, so a 12,000 BTU single-zone unit lands around $460 to $940 for the outdoor half.
• The band is driven by efficiency rating and brand tier, not by geography: these are manufactured goods shipped nationally.
• Single-zone condensers are markedly cheaper per BTU than multi-zone ones, which is why adding a second room costs more than half of a second system.

Outdoor condenser, multi zoneestimated, ±34%

• A multi-zone condenser costs meaningfully more per BTU than a single-zone one: it has to modulate independently for each indoor head, which needs more valves, more control and more compressor range.
• This is the reason a two-zone system is not two half-systems, and the single most misunderstood part of mini split pricing.

Indoor air handler (head)estimated, ±45%

• One per zone. Wall-mounted units sit at the bottom of the band; ceiling cassette and ducted heads at the top.
• Priced per unit rather than per BTU because the price difference between a 9,000 and a 12,000 BTU wall head is small compared with the difference between a wall head and a cassette.

Branch distribution boxestimated, ±44%

• Needed on most systems of three or more zones, to split refrigerant between the heads. Two-zone systems usually connect directly to ports on the condenser.
• A discrete component that appears at a threshold rather than scaling smoothly, which is why a third zone can cost noticeably more than the second.

Refrigerant line setestimated, ±42%

• Insulated copper pair, one run per indoor head. Priced per linear foot including insulation and fittings.
• Copper is a traded commodity, so this line moves with metal prices rather than with your location. The band covers line diameter, which follows the capacity of the head it feeds.

Line set coverestimated, ±47%

• Moulded plastic channel that hides the line set on an outside wall. Optional in function, near-universal in practice on a visible elevation.
• Leaving it off is the easiest way to make a mini split installation look cheap, which is usually a false economy on the front of a house.

Condenser pad or wall bracket, mounts and hardwareestimated, ±52%

• Ground pad or wall bracket for the outdoor unit, plus the mounting plates for each indoor head.
• Wall brackets cost more than pads and are common where snow load or flooding rules out setting the unit on the ground.

Condensate pumpestimated, ±51%

• Only where the indoor head cannot drain by gravity, which is common on interior walls and in basements.
• One per affected head; the calculator assumes one where the option is ticked.

Dedicated circuit, disconnect and whipestimated, ±52%

• Breaker, cable, outdoor disconnect and the whip to the condenser. A mini split needs its own circuit; it cannot share one.
• Excludes a panel upgrade, which is a separate project and is listed under what this figure does not include.

Electrician

• The wage behind the hour is official BLS data adjusted to your metropolitan area. The hours are our estimate.

HVAC installer: mount, run lines, evacuate and commission

• Six hours for the first zone and four for each one after it. The second zone is cheaper in labour than the first because the outdoor unit, the circuit and the crew are already there — which is the opposite of how the equipment behaves.
• Includes pulling a vacuum on the lines and commissioning the system, which is the step that most affects whether the equipment lasts.
• The wage is official and metro-adjusted; the hours are our estimate.

Wall penetrations, sleeves and sealingestimated, ±52%

• One three-inch penetration per indoor head, sleeved and sealed against air and water.
• Cheap in materials and worth listing separately, because a badly sealed penetration is a recurring cause of damp behind an indoor head.

Not included in this dataset

Permit fees and inspection

Most jurisdictions require an electrical and sometimes a mechanical permit. Fees vary by city with no national source, so they are excluded and stated rather than averaged.

Electrical panel or service upgrade

If your panel has no spare capacity, that is a separate project several times the size of this one. The electrical lines here cover a circuit, not a new service.

A Manual J load calculation

This calculator sizes from the ENERGY STAR area table, which is a screening estimate. A professional installation should be sized with an ACCA Manual J load calculation that accounts for insulation, glazing, orientation and infiltration. Expect an installer to charge for it, and expect their number to differ from ours.

Removing an existing system

Taking out old window units is trivial; decommissioning a ducted system, recovering its refrigerant and dealing with abandoned ductwork is not, and is not modelled here.

Utility rebates and tax credits

Heat pumps often attract substantial ones. They are excluded because they vary by utility, change without notice, and would make this figure look better than the quote you will actually receive.