If you are going to be dealing with refrigeration systems, then having access to one of the best HVAC vacuum pumps is essential to ensure you carry out a professional repair or maintenance job.
Without the best pump, it is likely that non-condensable molecules will be left behind; these are the molecules that will not participate during refrigeration.
Over time, these remaining contaminants can lead to a series of problems, including corrosion, oil breakdown and rust, which will gradually degrade the system
In this article, we will review some of the best HVAC vacuum pumps available and run you through the features that make all the difference when it comes to ease of use and efficiency – the things that actually matter!
Quick Picks: HVAC Vacuum Pump Reviews
What is a HVAC Vacuum Pump?
A pump is used to remove air, water and vapor from a refrigeration system when it is being serviced by a HVAC technician. The technical term for this procedure is called evacuation.
A refrigerant system should only ever have two components circulating, which are oil and refrigerant. However, during the servicing process and as a result of leaks, it is common for other contaminants to make their way in, this includes atmospheric gases such as oxygen and nitrogen, as well as water vapor.
It is essential that these contaminants are removed from the system using a pump, since they can cause a wide range of problems. This includes having a negative impact on the efficiency of the system, damage to other systems components and sludge formation.
The Economy pump is my recommendation for anyone on a budget as the Robinair brand is a vacuum pump company, rather than just a budget tool company.
The lightweight and durable design makes it a particularly useful for HVAC technicians on the move. Compared to many competitors it is a truly portable pump that even has a handle for added convenience.
It is a 2 stage pump that operates at 5 CFM – this means it will be able to create a superior vacuum when compared to single stage pumps. The first stage will create a medium vacuum, while the second stage is able to create a deeper vacuum using the exhausts from the first stage.
The oil fill and drain port are also easy to use and designed to make the process as simple as possible. Overall, this is a great pump that is able to achieve a < 500 micron vacuum, which although is less than more expensive units, will probably be a worthwhile trade off for most people, especially those mainly dealing with residential systems.
This high quality pump by Yellowjacket is a pricier options than others we have listed, yet it is far superior in terms of build and some people have reported it can deliver pulls down to a mighty >15 microns.
In addition to the power, it’s design is also far better. It features a steel handle to maintain balance and is equipped with a ball valve that allows you to separate the vacuum from the oil, in the event that you need to to change over the oil half way through a job.
Other features that make the yellowjacket pump stand out from the crowd include a built-in filter to guard against potentially harmful debris and an intake check valve which guards against overfilling in the event that the units power supply fails.
The Zeny pump is the perfect budget pump and is ideal for small jobs due to its portability. The aluminium casing also provides it with extra durability, making it ideal for almost any work environment.
Just like the other more premium units, the Zeny includes an oil reservoir with display window and drain plug, all conveniently positioned.
You do have the option of purchasing this with an add-on – a Manifold Gauge Set, which some people may find a better choice as you know it will be the right fit. That certainly beats trying to find one when it arrives.
Other great features include exhaust port, a cooling fan and a many report a quieter operation than other available models.
If you are looking for a high quality pump able to carry out evacuation procedures for small, medium and large applications, then the Kozyvacu is a great option. Essentially, it’s a good all rounder.
The shell is predominantly made from aluminium, which is far more durable than the cheaper plastic designs.
This pump also comes with a helpful user manual, which some people, especially newbies may find useful as you can easily refer back to the instructions inside.
In terms of micron rating, it has a very capable 150 microns rating, which is more than adequate for evacuating the typical refrigerant systems. Therefore, if you work in the HVAC industry this is a good choice that will do the job well.
What makes the Kozyvacu stand out against other units are its unique features. These include the motors thermal protection, the sight glass that allows you to keep tabs on the oil level and the large and easy to use oil valve and drain.
What is A Vacuum Pump Used for?
A vacuum pump is used in a wide variety of different industries for a variety of purposes. However, in the HVAC industry, technicians are most likely to require a pump when dealing with the repair and maintenance of refrigeration systems just like you would need refrigerant scales.
Over time refrigerant systems may require repairs and maintenance, for instance, in the event a refrigerant leak is suspected or routine servicing may be warranted.
In order to effectively assess the system and carry out repairs, the system needs to be emptied of refrigerant. This step is referred to as refrigerant recovery, which involves removing all refrigerant gas from the system and storing it to be re-used later.
Once the entire refrigerant has been removed, checks and repairs to the system can be carried out. After this process is completed, the refrigerant is ready to be put back into the system, which is commonly referred to as “recharging the system”.
However, before this process can take place, it is essential that evacuation takes place, which is where the best HVAC pump comes into the procedure. Evacuation essentially means removing all contaminants from the system using the best pump, prior to recharging the system.
Evacuation is important since leaving any remaining contaminants such as moisture and other gases from the atmosphere can cause long term problems to the system.
Types of Vacuum Pumps
There are three major types of pumps, each which vary in the way they achieve a vacuum. During evacuation, a HVAC technicians goal is to remove as much contaminants from the system as possible, therefore the vacuum the method that can achieve a vacuum closest to 100% will perform the best. Here is a brief overview of the three most common types of pump.
- Oil Filled Rotary Vane Pump – This is the go-to type of pump for HVAC technicians carrying out evacuation procedures. It is a relatively cheap method that attains a very strong 99.9% vacuum.
- Diaphragm Pump – This method can not achieve a strong vacuum, typically only ever reaching the mid 80’s.
- Vacuum Generator – This method creates a vacuum of around 93%. The downsides of this method is that it can be incredibly noisy, requires an costly air compressor and it doesn’t operate well in humid conditions.
Things to Look for in The Best HVAC Vacuum Pump
If you are in the market for a new pump, then there are a number of things to consider. Not all pumps are made equal, so bear these factors in mind when comparing different units and coming to a decision:
- Cubic Feet Per Minute (CFM Rating) – This is a measurement of how much air the vacuum pump can draw from the system per minute. Therefore, the higher the CFM rating, the faster the evacuation process will be.
If you are intending to use the pump for residential purposes, then most people recommend a CFM of around 4-6, while commercial applications typically require a CFM of around 8-10.
- Vacuum level (in microns) – Another important consideration is the vacuum level the pump can achieve. No pump is perfect and in reality only leave behind a partial vacuum. Vacuum levels vary and are measured in microns.
0 microns is a perfect vacuum, while 760,000 microns is the average for a space at sea level with no vacuum at all. Therefore, the lower microns the better.
- Sight Glass – This simple feature allows you to see the oil inside the reservoir and monitor it during use.
- Anti-suck back mechanism – If you happen to lose power during the evacuation process, you don’t want the oil from your pump to escape and be drawn back into the refrigeration system since this will contaminate it.
Therefore, only the best HVAC vacuum pump with an anti-suck back mechanism will prevent this from happening in unforeseen circumstances.
- Two Stage vs. One Stage Vacuum Pumps – A two stage vacuum pump has two sets of rotors and two sets of vanes. The first vacuum pump creates a medium sized vacuum, while the second utilises the exhaust from the first to create a more powerful vacuum.
So do you need a 1-stage or 2-stage pump? This will entirely depend on the speed of evacuation you require and noise desired level. So if you require a faster evacuation and want a quieter operation, choose a 2-stage pump.
What Size Vacuum Pump Do You Need?
As previously discussed the type of pump you need will depend largely on the type of systems you will be working with. If you work in the HVAC industry, then no doubt you will be using it with some type of refrigeration system, in which case the size of the system will be the deciding factor.
In order to figure out the CFM rating you will need you can utilize a simple formula.
CFM squared = Maximum System Tonnage
Therefore, if you are going to be evacuating a 49 tonne system, a vacuum pump with a CFM rating of 7 will be required.
In reality, the majority of technicians I know own a vacuum pump ranging from 5 – 7 CFM, as this is likely to be what is required for most residential work.
How to Use a Vacuum Pump for Evacuation Procedures
Some things are better shown through a demonstration rather than written instructions. This video provides a great overview of the overall refrigeration evacuation process from start to finish.
If you work in the HVAC industry and intend on evacuating a refrigeration system, it’s likely you will need to source the best HVAC vacuum pump.
There are many units available on the market, but in my view it’s always worth sticking to a reputable brand that has been around for decades, take Yellow Jacket for example.
In addition, you need to consider the type of work you will be carrying out on a routine basis. For instance, if you carry out more residential work, then it’s unlikely you will need a CFM above 6, so take this into account.
Even so, you will probably want a lightweight and portable pump that is easy to transport and fit in the back of your vehicle.
Other important factors include weight, intake fittings, sight glass and anti-suck back functions.
About the Author
Dave Miller is a HVAC technician with over 10 years in the industry. Dave created HeatTalk with the ambition for it to become a resource for individuals looking for answers, whether they be a layman, student or a professional.