The larger line typically carries a cool gas and is insulated. This is commonly referred to as the suction line, but it is also called the return line or vapor line. The smaller uninsulated line typically carries a warm liquid. It is most often called the liquid line.

Is the liquid line the high side?

The high side, or discharge line, will be the line connected to the compressor from the bottom or lower position. It will not be wrapped in insulation and will be warm to the touch. This is where freon exits the compressor as a liquid.

What is the liquid line?

LIQUID LINE – Pipe or hose connecting condenser to expansion valve. LOW SIDE – That portion of system from orifice in expansion valve through evaporator line or lines through compressor service valve to compressor reed valve. Also called suction side. out of a refrigeration system and stores it in a container.

Which side is the suction side?

The suction side of the unit consists of the lines that lead into the compressor, often called the low side of the refrigerant system, since the pressure in these lines is much lower to the lines on the compressor output. The lines rarely have dials that automatically show pressure.

Is suction line Hot or cold?

When the system is operating, the large insulated suction line should be cold to the touch and sweating at any point where there is no insulation. The smaller uninsulated liquid line should be warm to the touch after the system has been operating for 10 or 15 minutes.

Why is my liquid line so hot?

AC liquid lines can become very hot if there is a problem with the condenser, such as it being dirty, or not working properly. Clean your condenser, and if the problem continues you may need to replace it or troubleshoot further. If your liquid line is very hot, instead of warm, then there could be a problem.

Why is the suction line not cold?

The Copper Pipe (Suction Line) should be sweating and cold to the touch during a hot day. If it is not cold, your compressor could be off (bad capacitor/ hard start kit) or low on Refrigerant. Be Careful because this usually indicates a problem with the compressor or wiring.

What size is suction line?

The larger pipe is known as the suction line, and includes insulation. The diameter on the liquid line for standard residential systems is 3/8 inches in diameter. The suction line diameter is normally either 3/4, 7/8 or 1 1/8 inches, it depends on the size (and efficiency) of the air conditioning system or heat pump.

Why is suction line bigger?

The discharge pipe may be larger than the suction pipe. The purpose of the lines is to keep the losses to a minimum. This is done to make sure there is enough Net Positive Suction Head available to meet the requirements of the pump.

What are the three major refrigerant lines?

The suction line connects the evaporator to the compressor, the discharge line connects the compressor to the condenser, and the liquid line connects the condenser to the expansion device.

Which line is bigger liquid or suction?

The larger line typically carries a cool gas and is insulated. This is commonly referred to as the suction line, but it is also called the return line or vapor line. The smaller uninsulated line typically carries a warm liquid. It is most often called the liquid line.

Is AC low side liquid or gas?

The refrigerant, a chemical compound that changes easily from liquid to a gas. When the refrigerant is pushed into the compressor, it is a low pressure gas.

What is the normal suction pressure?

The normal range of the suction pressure is 0.8–1.2 MPa. If the suction pressure is greater than 1.2 MPa, connect a rubber hose for the pressure gauge to the gas pipe needle valve for the outdoor unit, and rotate open the pressure gauge to slowly release refrigerant. Start the compressor.

Why is the suction line insulated?

Insulating the suction line is done to prevent condensate from developing and dripping off. This condensate drip can cause water damage to the material under it or cause a slip hazard for people walking below it.

What temperature is suction line?

The suction temperature should be above 35°F and below 65°F entering the compressor and the discharge line temperature should be below 220°F and above 150°F (typically) on a properly functioning package unit.

What does a warm suction line mean?

AND THEN, because there is no freon getting into the suction line, the compressor is essentially making a vacuum on the suction line, which will make a hot. That’s why when the system is low on freon and you keep the system running, eventually the liquid line will be frozen and the suction line will be warm.

Do you insulate the suction or liquid line?

This is called the “suction” pipe and is typically the larger of the two pipes. There is no need to insulate the smaller, warmer copper pipe, often called the liquid line, because not insulating this line allows it to shed heat which is exactly what you are trying to do with an AC system.

Should AC suction line sweat?

A sweating suction line is perfectly normal. Excessive sweating might be caused by not insulated well enough or too cold due to poor air flow over the evaporator. Some types of systems might sweat a lot because of being overcharged but in that case, usually the whole compressor will be sweating.

What are the symptoms of an overcharged AC system?

Signs and Symptoms of Overcharged Car AC Faulty Cooling. One of the most evident signs of an overcharged AC is faulty cooling. Noisy or Broken Compressor. The AC works in a cycle transforming compressed liquid coolant into a gas then back to its liquid state. High Pressure. Failing Engine.

How do I know if my liquid line filter drier is clogged?

Temperatures Drop Across the Filter Drier A symptom of a clogged liquid line filter drier is a temperature drop across the filter drier. Filter driers are typically shaped like a hot dog and are about the same diameter.