Proper functioning of air conditioner is very important for the comfort of the occupants of the car. Especially while driving in hot and humid weather, an efficient air conditioner is must.

If you air conditioner is giving desired cooling it might be due to following factors:

Low Refrigerant: An A/C system requires a certain amount of refrigerant to cool properly. If low, it works less efficiently and does not cool well.

Dirty condenser: The condenser is the heat exchanger mounted in front of the radiator. It cools the high-pressure refrigerant vapor after it exits the compressor so it can condense into a liquid. If the condenser is full of leaves, bugs and road debris, airflow through the unit may be blocked to the point where little cooling occurs. Cleaning the condenser should cure the problem.

Blockages: Debris, rust or debris in the system may plug up the orifice tube or metering valve that admits refrigerant into the evaporator. If this vital point becomes obstructed, the flow of refrigerant may be restricted or blocked causing a loss of cooling-and possible compressor damage as well in systems that rely on oil circulating with the refrigerant for lubrication.

Air or moisture contamination: For the refrigerant inside the system to do its job properly, it must not be contaminated with air or moisture. Air reduces the cooling efficiency of the system while moisture can freeze and form ice that causes blockages in orifice tubes and metering valves. Air and moisture contamination may be the result of unrepaired leaks in the system, or failing to vacuum purge the system prior to recharging it with refrigerant.

Mechanical problem: These include things like metering valve failures, compressor wear and tear, a compressor clutch that fails to engage, bad pressure switches, etc. Pinpointing the problem will require the skills of a competent A/C technician.