How to Select the Right Size A/C Vacuum Pump

The A/C refrigeration vacuum pump is one of the most important tools an engineer will use during their role, as it is a key player when carrying out maintenance on air conditioning units.

The recovery of refrigerant is now legally mandated, so if any systems you are working on currently have refrigerant within them you will need to take appropriate steps to recover these gases. Their disposal can have a serious impact on the environment, albeit with some rules and regulations.

It is also worth noting that should the refrigeration be exposed to any form of moisture, then it could become corrosive and could cause problems with the air conditioning unit that could incur more expense in the future.

Knowing how important an A/C refrigeration pump is, it’s understandable that those who operate within the HVAC sector will want to ensure that they have the right tools to hand.

Those who have worked within the HVAC sector for some time will be familiar as to how different air conditioning units operate and what pump is needed to ensure the job is carried out correctly.

However, those who are using an A/C refrigeration pump for the first time may be confused as to what size pump they should purchase.

Determining the CFM Required (Cubic Feet Per Minute)

When ascertaining what refrigeration pump needs to be used, it’s important to determine the CFM rating required for a job. This is more commonly known in some countries as the LPM, Litres per minute.

This can mean that those dealing with a variety of air conditioning units may need to invest in more than one pump to ensure maximum productivity and ensure overheads are low.

This is often the case for engineers who operate on both commercial and residential properties.

The most practical way to decide what A/C refrigeration pump is needed is to take the square root of the tonnage you’re servicing. Examples of these calculations could be as follows:

  • 16ton to 25ton (Typical Residential A/C System) would require a pump with a 4 to 5 CFM rating.
  • 16ton to 25ton (Commercial Systems) would require a 6 to 8 CFM rating.
  • For anyone working on a kWh system, there is 7 kW per tonne.

It’s important that the right measurements are carried out when ascertaining what pump is the most suitable, or you could find that the job is more problematic than it needs to be.

Can’t I Use the Same Pump for All Jobs?

 It’s easy to assume that a larger pump can contend with all jobs. Although a pump with an 8 CFM raring will reach the maximum number of microns before a pump with a 4CFM, they do operate at the same speed when operating at maximum capacity.

This means that although a bigger pump may be able to contend with smaller jobs, it’s likely it will cost more to purchase.

Other Factors to Consider

 Once you’ve determined what size A/C refrigeration pump is needed, then it’s simply a case of finding a reputable supplier. Although it can be tempting to see what bargains are available from other vendors, if the price seems too good to be true, then it probably is.

When choosing an A/C vacuum pump, it’s important to ensure that you’re on only purchasing reliable tools from reliable suppliers such as HVAC tools.