Installing Central Air Conditioning for the First Time: What to Expect and What It Costs

Adding central air conditioning to a home that's never had it is one of the most impactful home improvements you can make - both for comfort and resale value. But it's also one of the most complex, because you're not just installing equipment; you're potentially adding ductwork, upgrading electrical, and modifying your home's structure. Here's the complete picture.

Option 1: Central Air with New Ductwork

If your home has an existing furnace with ductwork, adding central air is straightforward - you're essentially adding an outdoor condenser unit and an indoor evaporator coil that connects to the existing furnace and ducts. Cost: $3,500-$7,000. If your home has no ductwork at all, you'll need to install a complete duct system plus the AC equipment. Cost: $7,000-$15,000 including ductwork.

New ductwork installation requires space for trunk lines and branch runs, usually in an attic, basement, crawlspace, or between floors. Not all homes can accommodate ductwork without significant construction. A qualified contractor should assess your home's structure before quoting a ducted system.

Option 2: Ductless Mini-Split System

If your home lacks ductwork and adding it would be impractical or prohibitively expensive, a ductless mini-split system is the alternative. Mini-splits require no ductwork - just a 3-inch hole through the wall for the refrigerant line. A single-zone system costs $3,000-$5,000. A multi-zone system covering the whole home costs $10,000-$20,000. Advantages over ducted: no ductwork cost, room-by-room zone control, higher efficiency (no duct losses), and easier installation. Disadvantages: visible wall units, higher cost per zone for whole-home coverage.

Option 3: High-Velocity Mini-Duct System

SpacePak and Unico make high-velocity systems that use small, flexible 2-inch ducts that can be routed through existing walls and ceilings without major construction. The ducts are small enough to fish through walls like electrical wiring. Air is delivered through small, round outlets (about 5 inches diameter) in walls or ceilings. Cost: $8,000-$15,000 installed. This is the best option for older or historic homes where preserving architectural integrity matters.

Electrical Requirements

Central air conditioning requires a dedicated 240-volt circuit. Most modern homes have sufficient electrical capacity, but older homes (especially those with 100-amp service panels) may need an electrical panel upgrade to accommodate the AC unit. A panel upgrade from 100-amp to 200-amp costs $1,500-$3,000 and should be performed by a licensed electrician. Your HVAC contractor should assess electrical requirements during the initial estimate.

The Installation Process

Day 1 - Equipment and ductwork installation: The crew installs the outdoor condenser on a concrete pad, mounts the indoor evaporator coil on or near the furnace, runs refrigerant lines between the units, connects to existing ductwork (or installs new ductwork), and runs the electrical circuit to the outdoor unit.

Day 2 (if needed) - Completion and testing: Complete any remaining ductwork, charge the system with refrigerant, test all components and airflow from every register, program the thermostat, and walk the homeowner through operation and maintenance.

A straightforward installation (existing ductwork, adequate electrical) typically takes 1 day. Installations requiring new ductwork take 2-5 days depending on home size and complexity.

Resale Value Impact

Central air conditioning adds significant resale value, especially in warm climates. Studies show that central AC adds 5-10% to home value in hot markets and is increasingly expected by buyers even in moderate climates. In many markets, a home without AC sells slower and at a discount. The $5,000-$12,000 investment in central air typically returns 50-100% of its cost in increased home value - in addition to the comfort and energy benefits you enjoy while living there.

Best Time to Install

Schedule installation in spring or fall. Contractors are less busy, scheduling is easier, and you may get better pricing. Avoid scheduling in June-August when demand is highest, wait times are longest, and emergency installations get priority over new installations. If you know you want AC for summer, start getting quotes in February-March and schedule installation for April-May.