Air Conditioning Design, Inc. offers several contracts to our customers for maintenance and repair.  Simple Maintenance Contract The simple maintenance contract includes basic maintenance such as filter and belt replacement. Custom Contracts The custom contract includes in detail any mechanical equipment the building chooses to have maintained. Flat Rate Maintenance Contract This contract not only includes the general maintenance, but also comes with a guarantee that all costs for all failures will be covered. All repairs and replacements are done without any hidden costs. This contract allows your company to budget the year without worrying about potential costs of replacing a unit.