The cost to replace a home air conditioning unit can vary depending on several factors, such as the size and type of the unit, the complexity of the installation, and the location of the home. On average, homeowners can expect to spend anywhere from $3,500 to $7,500 for a new central air conditioning unit, including installation. However, it's important to note that this is only a rough estimate, and homeowners should get multiple quotes from reputable HVAC contractors before making a final decision.