Understanding R407a Suction and Discharge Pressure in HVAC Systems

As an HVAC technician, it is crucial to have a comprehensive understanding of the pressure characteristics of refrigerants used in different systems. In this article, we will delve into the specifics of R407a, focusing on its suction and discharge pressures in HVAC systems.

Introduction to R407a

R407a is a refrigerant gas commonly used in refrigeration and air conditioning systems. It is a blend of several gases and is known for its efficient cooling properties. However, it is essential to note that R407a exhibits a phenomenon known as refrigerant creep, where there can be a small increase in temperature during its phase change.

Table of Pressure and Temperature

The table of pressure and temperature of R407a provides valuable insights into its operational characteristics. When analyzing the table, it becomes evident that R407a experiences slippage, meaning its temperature changes during evaporation. This aspect is crucial to consider when recharging with R407a, as it directly impacts the system’s performance.

Suction and Discharge Pressures

In HVAC systems utilizing R407a, monitoring suction and discharge pressures is vital for ensuring optimal performance and efficiency. The suction pressure, also known as the low-pressure side, is a key indicator of the refrigerant’s state as it enters the compressor. On the other hand, the discharge pressure, or high-pressure side, reflects the pressure of the refrigerant as it leaves the compressor.

Practical Application

To illustrate the practical application of understanding R407a suction and discharge pressures, let’s consider a scenario. For an evaporator temperature of 5 degrees Celsius, the corresponding suction pressure for R407a is approximately 41 PSI. This example highlights the direct correlation between temperature and pressure in R407a systems.


In conclusion, a thorough comprehension of R407a suction and discharge pressures is indispensable for HVAC technicians. By closely monitoring these pressures and understanding their relationship with temperature, technicians can effectively diagnose and troubleshoot issues within refrigeration and air conditioning systems utilizing R407a.

Remember, for any maintenance tasks related to refrigeration and air conditioning, it is essential to utilize high-quality tools and equipment. Additionally, staying updated with the latest industry information and best practices is crucial for delivering top-notch service to clients.

Leave a Reply

Your email address will not be published. Required fields are marked *