This is not a comprehensive list, but some of the most common items that could increase or decrease the price of your system:

1. Accuracy of the form- Most homeowners do not no for sure if refrigeration lines or venting can be reused. This can increase or decrease the cost of the job.

2. Electrical upgrades- The most common electrical upgrade is the disconnect. All outdoor units, by code, must have a properly sized disconnect that is accessible. The units today are much bigger and codes have also changed, so it is possible a disconnect might need to be moved in order to provide proper access to it. Other upgrades can include lighting or plugs in the attic.

3. Carpentry- Sometimes units are placed in the attic or in a closet before the house is drywalled and trimmed. This causes the access to be too small and can often require a carpenter. Recent code upgrades, including equipment clearances and attic walkways could also require some additional work.

4. Condition of ductwork/plenums- Ductwork or plenums that are in bad repair could require some upgrades.

5. Factory offers/incentives- Trane offers different incentives throughout the year.