What Size Vacuum Pump Do I Need for Mini Split?

When it comes to maintaining and servicing a mini-split air conditioning system, one of the most critical tools you’ll need is a vacuum pump. The vacuum pump is responsible for removing air, moisture, and other contaminants from the refrigerant lines, ensuring the system operates at peak efficiency. Choosing the right size vacuum pump for your mini-split system is essential to ensure proper performance and prevent potential issues.

Determining the CFM Rating

The primary factor to consider when selecting a vacuum pump for a mini-split system is the CFM (Cubic Feet per Minute) rating. The CFM rating represents the volume of air the pump can move in a minute, and it’s a crucial metric for determining the appropriate pump size.

For a typical residential mini-split system, a vacuum pump with a 3 to 5 CFM rating is generally sufficient. However, for larger commercial or industrial mini-split systems, a pump with a 6 to 8 CFM rating may be required to handle the increased refrigerant line volume and achieve the necessary vacuum level.

It’s important to note that the CFM rating is not the only factor to consider when choosing a vacuum pump. Other factors, such as the size and type of the mini-split system, the length and diameter of the hoses used, and the desired vacuum level, also play a role in determining the appropriate pump size.

Factors to Consider

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  1. System Size and Type: The size and complexity of the mini-split system you’re servicing will directly impact the vacuum pump size needed. Larger systems with longer refrigerant lines or multiple indoor units will require a higher CFM rating to achieve the necessary vacuum level.

  2. Hose Length and Diameter: The length and diameter of the hoses used during the evacuation process can also affect the required CFM rating. Longer hoses or hoses with a larger diameter will require a higher CFM pump to maintain the desired vacuum level.

  3. Desired Vacuum Level: The target vacuum level for the mini-split system is another important consideration. Higher vacuum levels, typically around 500 microns or lower, will require a more powerful vacuum pump with a higher CFM rating to achieve and maintain the necessary vacuum.

  4. Maintenance and Oil Changes: Proper maintenance of the vacuum pump, including regular oil changes, is crucial to ensure optimal performance and longevity. Neglecting maintenance can lead to decreased CFM and reduced vacuum capabilities, potentially causing issues during the evacuation process.

Vacuum Pump Brands and Models

When it comes to vacuum pumps for mini-split systems, there are several reputable brands to consider, including:

  • Robinair
  • Fieldpiece
  • JB Industries
  • Mastercool
  • Yellow Jacket

These manufacturers offer a wide range of vacuum pumps specifically designed for HVAC applications, with varying CFM ratings to accommodate different system sizes and requirements.

For example, the Robinair VacuMaster Series offers models ranging from 3 CFM to 8 CFM, allowing you to select the appropriate pump for your mini-split system. Similarly, the Fieldpiece VP85 and VP95 models provide 5 CFM and 8 CFM ratings, respectively, catering to a variety of mini-split system sizes.


Selecting the right size vacuum pump for your mini-split system is crucial to ensure proper evacuation and maintain the system’s efficiency. By considering the CFM rating, system size and type, hose length and diameter, desired vacuum level, and proper maintenance, you can choose the appropriate vacuum pump to effectively service your mini-split air conditioning unit.

Remember, following the manufacturer’s recommendations and guidelines, as well as consulting with HVAC professionals, can help you make an informed decision and ensure the long-term performance and reliability of your mini-split system.


  1. How to Select the Right Size A/C Vacuum Pump – HVACTOOLS NZ
  2. Will this Vacuum pump work for a mini split? | The Garage Journal
  3. Vacuum pump CFM, does it matter? – HVAC-Talk