The Mercedes SDL recommended refrigerant (R12 type) capacity is 2.8 lbs., or 1.27 kg. Some models may list a range of 2.2 - 2.9 lbs. It is important not to exceed the recommended capacity!
You need to to add more conditioner fluid in the system.
The air conditioner needs regassing
What is the difference between rated capacity and the nominal capacity
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The energy requirements for a 120-volt air conditioner depend on its cooling capacity, measured in British Thermal Units (BTUs). A typical 120-volt air conditioner with a cooling capacity of 10,000 BTUs requires around 1,000 watts of power to operate efficiently.
R 12
134a refrigerant.
The cooling capacity of an air conditioner is measured in British Thermal Units (BTUs) per hour. It indicates how much heat the unit can remove from a space in an hour. To determine the appropriate cooling capacity for your home, consider factors such as the size of the room, insulation, and climate. It is recommended to consult with a professional to ensure you choose the right size air conditioner for your needs.
To determine the size of air conditioner you need for your room, measure the square footage of the room and use a sizing chart provided by the manufacturer. This will help you select an air conditioner that is the right capacity for your space.
Did you check the AC fluid? That is sometimes the problem.
1999 E320 air conditioner work on first and second speed, after 3rd blow warm air. AKINOHD@YAHOO.COM
2 pounds four ounces