If your HVAC unit’s performance is dwindling, it may be time to consider a replacement. Full HVAC unit replacement costs are between $5,000-$10,000. Factors impacting const include size and brand of the HVAC unit, size of the house, required ductwork, and the unit’s efficiency rating. New installations typically cost between $1,500-$12,500, which includes labor expenses of $500-$2,500. Other factors that will impact the cost include removal and disposal of an existing unit, adding zones and thermostats, additional ductwork, and additional insulation if required. Note that it typically costs more to install a new system than to replace an existing one. Learn about HVAC system types and installation requirements and costs.