Discharge vs Suction Line Hose

Discharge vs Suction Line Hose

Does your car’s A/C hose need replacement? But you can not differentiate between the discharge line and suction line hoses? Or do you want to know your A/C refrigeration system better? Whatever the reason is, a comparison between discharge vs suction line hose can answer all of your questions.

The key difference between a discharge and a suction line hose is their connection system. A discharge line hose connects the compressor outlet to the condenser inlet. And the suction line hose links the evaporator outlet to the compressor inlet. Both of them transfer refrigerant through the connections.

Their overall usage and function are quite different from each other. Here we have explained all the information about the discharge and suction line hose and their differences. You can use this knowledge to determine which hose you need to fix your A/C.

Read More: Discharge vs Suction Hose

What Is Suction Line and Discharge Line

The suction line and discharge line are two types of hose found in automotive A/C systems. These hoses transfer refrigerant vapor to produce cold air that keeps the cabin cool.

Usually, an A/C system has four major components: evaporator, condenser, compressor, and expansion valve. The discharge side includes compressor and condenser, and the suction side includes expansion valve and evaporator.

First, the compressor compresses the gas refrigerant that generates heat, and then the condenser eliminates the excess heat. A discharge hose connects between the compressor and condenser. 

The high-pressure refrigerant travels to the expansion valve that regulates it to the evaporator. And now the refrigerant inhales the heat from the cabin and fans out the cold air. The suction line hose then conveys the refrigerant from the evaporator to the compressor.

Discharge vs Suction Line Hose: Key Comparison Chart

Basis of comparisonDischarge line hoseSuction line hose
ConnectionCompressor outlet to condenser inletEvaporator outlet to the compressor inlet
CostMedium to expensiveCheap to medium

Discharge vs Suction Line Hose: Key Differences

Above, we have provided a brief table showing the differences between a discharge and a suction line hose. Below is the detailed explanation:


Discharge and suction line hoses connect different components of an A/C system. Discharge transfer refrigerant from compressor to the condenser. Similarly, a suction line hose conveys refrigerant from the evaporator to the compressor.

Refrigerant Pressure

The refrigerant discharge hose transfer is high pressure. When the refrigerant gets into the evaporator, the pressure gets down. And then, a suction hose transfers low-pressure refrigerant.


Similar to the pressure, the discharge line is high or hot, and the suction line has a cold temperature. Before the cold air cools the cabin, they go through the suction line. 


Though they have high pressure, discharge line hoses are smaller. And the suction line hoses are the larger ones. They transfer refrigerant vapor and lubricant, which need plenty of space to flow properly.


The cost of discharge lines and suction line hoses are almost the same. However, a good quality discharge line hose may cost higher than a good suction line hose.

Read More: Corrugated vs Braided Hose

Is the Suction Line Bigger Than the Discharge Line?

Yes, the suction line is bigger than the discharge line in the refrigeration system. This is because the volume of the refrigerant gas that the suction line hose carries from the evaporator is much higher than when it enters the expansion valve.

Is the Suction Line Big or Small?

The suction line is usually the big line hose in the A/C refrigeration system. It carries low-pressure and cold refrigerant to the compressor from the evaporator. A suction hose is also called a return line or vapor line as it sends back the vapor that earlier came from the compressor.

Is High Side Suction Line or Discharge?

The high side of the A/C refrigeration system is the discharge line. Here the gas refrigerant enters and then gets out in the liquid form. Then it travels to the suction line or the low side. 

Should Suction Lines Be Hot?

No, the suction lines should not be hot. It is the low-pressure side that has a lower temperature. So, when you touch a suction line, it will be cold. You will also notice the line sweating where there is no insulation. 

Best Discharge Line:

The discharge line of your car’s refrigeration system may deteriorate over time. When it is not working anymore, you can easily replace it. But the availability of numerous products may confuse you about which one to buy. Here’s our favorite pick you can try:


Highlighted Features:

  • Extensive engineering ensures high precision
  • Premium quality materials
  • Tested for leak-resistance
  • High-pressure

This Discharge Line Hose from UAC is an excellent replacement for any car’s refrigeration system. UAC always tests its products multiple times on various measures to ensure good quality. It is our favorite because it offers excellent quality in this price range.


The UAC Discharge Line Hose is a high-pressure line you can get as a replacement for the one that is faulty. It uses premium-grade materials to ensure long-lasting performance.

Leaking has been one of the common problems for A/C hoses. This has been tested to prevent leaking quite efficiently. Overall, one of the best replacement discharge lines available in the market.

Best Suction Line:

You may also require a suction line hose to fix the A/C in your car. When buying a suction line, you need to be careful as wrong choices can lead to replacement sooner than later. Here’s our favorite suction line:

1. UAC HA 111357C A/C Suction Line Hose

Highlighted Features:

  • It weighs only 3.2 ounces
  • Premium-quality design to meet OEM specifications
  • Hoses used in the assembly: Goodyear / Veyance / Contitech Galaxy.
  • Dimension: 12.5 x 7.8 x 9.7 inches

UAC has been quite popular in offering high-quality automotive parts and components, and this Suction Line Hose is no different. Its high-quality construction with such a low price makes it our favorite.

UAC Suction Line Hose Review:

It’s a low-pressure, lower-side suction hose. The use of premium quality materials helps it to prevent leakage and be highly durable.

Users have said the install process is quite simple. The low price of this line hose is the best thing about it. Overall, a good product at an affordable price.


The article provided all the information regarding the discharge vs suction line hose. They have different pressure and temperature and connect various A/C components. We hope now you can select the correct line hose replacement for your vehicle.

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