Buyer’s Guide: What to Look for in an HVAC Vacuum Pump

HVAC vacuum pumps are an essential tool for HVAC technicians and contractors, as they play a crucial role in removing air and moisture from the refrigerant system before charging it with refrigerant. A vacuum pump helps to ensure that the HVAC system operates efficiently and effectively, thus providing another happy customer indoor comfort and lower energy costs.

When looking for an HVAC vacuum pump, there are several key factors that you should consider to ensure you make the right choice. Here are some of the most important ones:

Oil Condition and Changes

Clean oil plays an important role in the performance of your HVAC vacuum pump, and is the single most important factor in how quickly a vacuum pump can remove all moisture and non-condensable gasses from an HVAC system. They should provide clear visibility of the condition of the oil, those with a backlit reservoir being the easiest to view and assess.

The best HVAC vacuum pumps also have technology that allows you to change oil without powering down and losing vacuum. The Fieldpiece VP67, VP87 and VPX7 with the RunQuick® oil change system are great examples, allowing for oil changes in less than 30 seconds with no mess.

Flow Rate: CFM

The vacuum flow rate is another critical factor to consider when purchasing a HVAC vacuum pump. The cubic feet per minute, or CFM, directly affects the time it takes to evacuate the air from the system, and the higher the CFM the faster the job can be completed given proper hose configuration. Most HVAC pumps flow rate vary between 2 and 10 CFM. As a rule of thumb, most residential homes require a 5-CFM pump. Systems with longer line sets require up to 10 CFM.

Pump Power

While pump power and CFM rate are related, they are worth considering separately. Most vacuum pumps have a power rating between 1/4 and 3/4 HP. This gives you an idea of how well the pump operates under real-world conditions.

Ultimate Vacuum Pressure

The ultimate vacuum pressure is the lowest pressure that the vacuum pump can achieve. The lower the pressure, the better the vacuum pump will perform in removing air and moisture from the system. Look for HVAC vacuum pumps with 15 microns ultimate vacuum or better to get the job done.

Size and Portability

The size and portability of the vacuum pump are also essential considerations given the variability of job sites technicians often work in. A vacuum pump that is lightweight and portable is easier to carry around, and does not always result in lesser performance.


A HVAC vacuum pump is an investment, and you want to ensure that it lasts for a long time. Look for vacuum pumps that are made from durable materials and that have a solid construction. Additionally make sure it has a wide base to help ensure it will not tip over or spill oil.

By considering these factors you can find the right vacuum pump for you and ensure you can service your customers effectively. Fieldpiece offers three levels of HVAC vacuum pumps. With 6 CFM, 8 CFM, and 10 CFM options that both feature the RunQuick® oil change system, and are lightweight and durable, you are sure to find a HVAC vacuum pump to meet your needs.







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