How much does central air installation cost with existing ductwork?

Central air installation with existing ductwork is priced case by case after an in-home evaluation. Most of the cost comes from matching the right system size and efficiency to your home, then addressing any electrical, refrigerant, or duct updates the install requires. A properly permitted and sized install prevents comfort issues and code problems. In many homes with ducts, small modifications—like sealing or balancing—sharpen airflow and cut noise. Our team handles these installs across the Lafayette area. Free in-home consultation and estimate are available.

Your price is typically driven by:

• AC capacity (tonnage) and efficiency rating (ENERGY STAR/SEER)
• Equipment features (single-stage vs variable-speed, thermostat upgrades)
• Line-set, pad, and electrical requirements
• Duct condition, sealing, and airflow balancing

Schedule a free in-home visit to receive a firm written quote after we inspect your ducts and electrical.

Updated: 2026-08-01

Need help in Lafayette, CO? Call (720) 577-4266 or book online. "Really happy with our new ac install. Prompt, professional and courteous!" — Tj S.