Choosing a Contractor
What to Look for in Professional Service

When your air conditioner needs more than the regular maintenance described previously, hire a professional service technician. A
well-trained technician will find and fix problems in your air conditioning system. However, not all service technicians are competent.
Incompetent service technicians forsake proper diagnosis and perform only minimal stop-gap measures.

Insist that the Technician:
1.        check for correct amount of refrigerant;  
2.        test for refrigerant leaks using a leak detector;  
3.        capture any refrigerant that must be evacuated from the system, instead of illegally releasing it to the atmosphere;  
4.        check for and seal duct leakage in any part of your system that runs in the attic, crawl, or garage  
5.        measure air-flow through the evaporator coil;  
6.        verify the correct electric control sequence and make sure that the heating system and cooling system cannot operate
simultaneously;  
7.        inspect electric terminals, clean and tighten connections, and apply a non-conductive coating if necessary;  
8.        oil motors and check belts for tightness and wear;
9.        check the accuracy of the thermostat.

How to Choose a Contractor
Choosing a contractor may be the most important and difficult task in buying a new central air conditioning system. Ask prospective
contractors for recent references. If you are replacing your central air conditioner, tell your contractor what you liked and did not like about
the old system. If the system failed, ask the contractor to find out why. The best time to fix existing problems is when a new system is being
installed.
When designing your new air conditioning system, the contractor you choose should:
1.        use a written calculation procedure or computer program to size the air conditioner;
2.        provide a written contract listing the main points of your installation that includes the results of the cooling load calculation;  
3.        give you a written warranty on equipment and workmanship.
Avoid making your decision solely on the basis of price. The quality of the installation should be your highest priority, because quality will
determine energy cost, comfort, and durability.