If you are testing for leaks, making repairs, removing HVAC parts, or need to recover and refill refrigerant, you need an HVAC vacuum pump. There is no way around it. You need to create a vacuum in the refrigerant lines for these projects, and more.
This article will show you the best HVAC vacuum pumps, reviewed, examined, and detailed for you. Don’t waste time or money on equipment you don’t need or can’t use. These HVAC pumps will get the job done and help you keep money in your wallet.
How AC Vacuum Pumps Work
A vacuum pump is a compact, heavy piece of equipment with a lot of hose connections, dials, and outlets to manage. However, once you get over the initial appearance, they are simple to use.
Aside from the pump, you will need high-pressure hoses, a recovery tank, and an extension cord. You will connect the hoses to the recovery tank and the high and low lines of the condenser unit. When you turn the pump on and open the valves, the pump will remove the refrigerant, water, moisture, and oils from the lines.
The recovery tank holds the old refrigerant and other impurities. Once the tank is closed off, the pump will continue to pull out the air in the lines. This creates negative pressure, or vacuum.
That vacuum will tell you a lot about the system. For example, if the negative pressure doesn’t hold for at least 10 minutes, there is a leak in the system somewhere. Once you have reached the vacuum pressure required for the system, you can then add new refrigerant easier.
Advantages of Owning a Vacuum Pump
Vacuum pumps have more uses than just your HVAC system. In fact, you can use them on your cars, small appliances, sewage and water lines, and several other uses. Owning a vacuum pump isn’t something that will just sit in your garage, waiting for your AC to break down.
If you are an HVAC professional, you will use a vacuum pump almost every day. DIYers and homeowners may not use one as often, but the options are there, and it is worth the investment for anyone looking to save time and money on costly home repairs.
HVAC Pump Compared
HVAC Vacuum Pump Buying Guide
Before you head out and buy your next HVAC vacuum pump, there are several things you need to consider. Figuring out the following details will help you find the right model and best price for your needs.
The most significant factor to consider is how much (and how quickly) the pump can create the vacuum. This measurement is rated in cubic feet per minute (CFM). You can get a decent estimation of your required CFM by doing a lot of complicated math. You can take the ambient temperature, along with other measurements such as constant flow rate, pressures from pipe 1 and pipe 2, etc.
Look, you don’t need the calculations for a good estimate, so don’t get overwhelmed. You will need to do some math, but I can make it easy for you. The CFM rating needs to be larger than the unit size you are working on.
All vacuum pumps, regardless of CFM, will, eventually, get your vacuum levels to where they need to be. If you want to do it without wasting a lot of time, look at the AC tonnage, then add 2. There’s your math. So if you are working on a 2-tonne AC unit, you need a vacuum pump with a CFM rating of 4. Simple enough?
Most residential requirements will fall between 4 and 6 CFM. Commercial and heavy-duty applications may want to boost that up to 8 CFM to be on the safe side. Anything higher than that, unless you are dealing with industrial systems, is overkill and not needed.
The other rating you need to know of is the micron rating. This is the vacuum level the pump produces. No vacuum at sea-level results in a micron measurement of 760,000. A perfect vacuum is zero microns. For your HVAC systems, you won’t need a perfect vacuum.
Look for a micron rating of at least 500. Anything higher is good, anything less, and you find that reaching the required vacuum level is difficult. Ideally for home use, a 500–700-micron rating is preferred. Professional applications may require more.
Regardless of the HVAC vacuum pump type, which I will cover later, the motor power is also important. Single-stage vacuums work well and should suffice for most usages. You may find an offering for a dual-stage or 2-stage motor. The second stage uses more power to create a faster, stronger vacuum and removes more impurities (moisture, oil, etc.) from the system.
The weight of the unit is a concern, but not much, You don’t need to hold the units while they are working. However, if you will be carrying the pumps a lot, you may want to find a lightweight model. For the most part, though, the overall weight of the pump itself is of little concern.
Rotary vane pumps require oil to run the motors. These models will come with a sight glass so you can see the oil level. If you happen upon a model that doesn’t have a sight glass, you should consider a different unit.
Without a sight glass, you won’t know when the oil is running low or needs to be refilled. This can cause irreparable damage to the motor and pump assembly and cost you more in repairs. It is better to pay a little more, if required, to find a model with a sight glass.
Vacuum pumps aren’t quiet machines. While some are louder than others, they all get pretty noisy. If you are working outdoors, this won’t be much of an issue. However, if the unit is in a garage or in an enclosure, you may need to add earplugs or headphones to your budget.
Oil Drainage System & Plug
The rotary vane systems need oil changes regularly. They also need refills during use occasionally. The sight glass (mentioned above) will help you determine when. However, an accessible oil plug and easy to drain system will go a long way to getting you back to work.
The additional features are where you will find the main differences between models. There are some features that you should consider “must-have,” such as an anti-suck back. This feature prevents air or liquid from reentering the system when you shut the pump off.
Other things to be on the lookout for are various sized intake fittings, which will help you use other equipment you already own, and isolation valves to help you control where the vacuum stops or if you need more control over the process.
Don’t forget to look at the types of pressure readings as well. Analog gauges are the most common, but the technological age is now allowing us to add digital screens and even wireless or Bluetooth connectivity with mobile apps for monitoring.
7 Best HVAC Vacuum Pumps Reviewed
Here I offer you the 7 best HVAC vacuum pumps on the market today. Depending on your usage needs or vacuum pump requirements, you will find the perfect model for you in the list below.
1. Yellow Jacket 93580 Superevac
Best High End HVAC Vacuum Pump
|Air Displacement||8.0 CFM rating|
|Oil Capacity||4.7 oz.|
|Factory Rating||15 Micron Rating|
|Warranty||2-year warranty on parts and labor|
The Supervac series from Yellow Jacket is made for professionals. With a 15 micron rating reduces contaminates to virtually nothing, and the two-stage motor gives you a quick, efficient vacuum that will hold.
The 93580 comes with a lot of smaller features that you may not notice but will definitely appreciate. The isolation valves allow you to drain, fill, or refill oil without losing vacuum. Also, everything on the unit is tethered. The drain plug and intake caps are all connected, so you won’t lose them after removal.
The drain fill is brass and wide-mouthed for easy pour and quick changes. You will also find the base is made from sturdy metal and has a rubberized coating to help prevent slipping. Everything about this unit screams durability, high-quality, and experienced craftsmanship. So much so, Yellow Jacket backs it with a two-year warranty.
While the best high end HVAC vacuum pump may be a bit too much for the average homeowner or DIY user, the professional will appreciate the daily use capability and high CFM rating for use on almost any system with ease.
This best rated system does weigh about 33 pounds, but it comes with a built-in shoulder strap to help in transportation and portability.
- High-grade metal and brass for durable construction
- No-slip bottom for stability
- Isolation valve to change oil without losing vacuum
- Heavy unit for everyday use
- May not be suitable for DIYers
2. FJC (6909)
Best Single Stage Vacuum Pump
|Air Displacement||3.0 CFM rating|
|Oil Capacity||6.5 oz.|
|Factory Rating||75 Micron Rating|
|Warranty||1-year warranty on all parts|
If you are a DIY repairman or homeowner and are looking for the best HVAC vacuum pump for the money, look no further. The FJC model 6909 uses 3 CFM to pull a vacuum on your AC system. The pump is designed for (and by) automotive experts, and will work great on most residential HVAC systems as well.
You don’t have the luxury of some professional-grade features, though. There isn’t an isolation valve, for example. If you need to add oil or change the oil, the machine needs to be off and no under vacuum.
With a two-port setup, the vacuum it pulls is faster than most single-stage pumps. The second chamber also allows the unit to hold the vacuum at a more steady level than most like a two-stage pump will.
All FJC pups come with a 1-year warranty. The simplistic design makes the unit easy to operate, and with fewer pieces, there isn’t much need for the warranty. If you keep the motor in good repair, clean and maintained, it will last you several years without worry.
- Lightweight for easy carrying
- Simple to set up and use
- 3 CFM is ideal for most automotive applications
- Works like a 2-stage but doesn’t have the micron rating of one.
- No isolation valve
3. Kozyvacu TA350 KZTA350001
Best Versatile Vacuum Pump
|Air Displacement||305 CFM rating|
|Oil Capacity||9.5 oz.|
|Factory Rating||150 Micron Rating|
|Warranty||90-day refund, 12-month exchange|
If you are looking to do more with your vacuum pump, the TA350 from Kozyvacu might be just what you need. While this single-stage, 3.5 CFM motor will pull a vacuum on home and auto AC systems, it is also used for many other home uses.
Want the best versatile vacuum pump? You found it. Wineries will find it is ideal for degassing wine, and ranchers will love the ease at which it runs automatic milkers. While the 150-micron rating may not be ideal for professional or industrial use, it is good enough for residential and automotive applications.
Without an isolation valve, you will need to stop the pump before adding or changing oil. The process is made simple with a large fill spout and angled drain plug. However, the biggest problem is that there isn’t a built-in vacuum gauge. You can use your charging manifold if it is rated to read down to 30 inHg or purchase a separate in-line.
The massive exhaust fan will help keep the motor cool, which allows you to use the pump for prolonged periods. However, you don’t want to leave the pump while you are off doing something else. Even with the thermal protection, the motor can still overheat.
- Lightweight and easy to move
- Twin inlet ports for Flare and ACME
- Multiple non-HVAC uses
- No built-in vacuum gauge
Best Heavy Duty HVAC Vacuum Pump
|Air Displacement||3.0 CFM rating|
|Oil Capacity||7.5 oz.|
|Factory Rating||75 Micron Rating|
|Warranty||1-year on all parts|
XtremepowerUS gives you the best heavy-duty HVAC vacuum pump on the market. Long-time rivals of Richie Yellow Jacket, XPUS offers a vacuum pump kit that will handle almost any job you take it to. The included carrying case makes sure you get there safely and with little effort, too.
Inside the case you will find a charging manifold set with 6-foot high-pressure hoses and manifold gauges. The pump also comes with a bottle of oil, which fills easily or changed as needed through the angled drain valve and fill port.
The simple operation of the pump is something to note as well. Once your lines are connected, you need only to plug it in and turn the switch on. The efficient and quiet motor does the rest.
A single-stage pump that can pull less than 100 microns is a great deal and rated at 75 microns this model does just that. The lack of isolation valve may be a turnoff to the professional user, but most applications won’t require a mid-vacuum oil change.
- Kit includes everything you need for HVAC vacuum
- Durable design and construction
- Built-in high volume fan allows continuous use.
- No isolation valve.
- Gauges for vacuum are on the manifold set.
5. ZENY 3.5 CFM Economy Vacuum Pump
Best HVAC Pump For Car AC
|Air Displacement||3.5 CFM rating|
|Oil Capacity||8 oz.|
|Factory Rating||120 Micron Rating|
|Warranty||1-year warranty on parts and labor|
ZENY isn’t a well-known name, yet. But for the automotive industry or those with a winery, you will soon know the brand. This economy model might be the best HVAC pump for car AC systems around.
In a world of you get what you pay for, this vacuum pump delivers. The budget-friendly model is not suited for daily or consistent use, but for light projects and DIYers, it is a dream come true. You need not spend hundreds to pull a vacuum on a line. The ZENY vacuum pump proves that.
Rated at 120 microns, the pump will pull and maintain a vacuum on automobile AC systems, automatic milkers, and wine degassing with ease. At 3.5 CFM, it won’t take you very long, either. I would suggest you start with a higher grade oil than the manufacturer provides. Otherwise, you are bound to experience oil leaks.
If you experience a leak, it will be challenging to make a warranty claim. Customer service isn’t up to par yet. Your best option is to purchase through Amazon and use their claim center for any issues.
- Simple operation for many uses
- Automotive vacuum at 100 – 120 microns is ideal
- Sturdy base won’t slip or fall when placed in the engine compartment
- Known to leak oil after several uses.
- Need fitting adapters for R-134a
6. Robinair (15500) VacuMaster
Best 2-Stage HVAC Vacuum Pump
|Air Displacement||5.0 CFM rating|
|Oil Capacity||7.5 oz.|
|Factory Rating||35 Micron Rating|
|Warranty||1-Year on parts and labor|
The Robinair VacuMaster is arguably the best 2-stage HVAC vacuum pump around. It pulls an incredible 5 CFM and, with the dual stages, can vacuum 35 microns, leaving you a near-perfect vacuum in any conditions.
The aluminum housing dissipates internal heat rapidly and becomes hot to the touch within minutes. However, it is better to have a heated outside than an internal one. The high-capacity fan ensures the motor doesn’t overheat for continuous usage.
Whether you are a homeowner, HVAC technician, or DIYer with multiple projects, the Robinair model is perfect for almost every situation. You can get inlet adapters to pull a vacuum on smaller lines such as automotive ACs, gas lines, sewage lines, and even drain pipes.
In reality, there isn’t much this model cannot do. While it isn’t as powerful as the Yellow Jacket model (our top pick), it will get the job done. Durable, rugged, and easy to use, the VacuMaster 15500 will make you look like a pro if you aren’t one already.
- High CFM (5.0) for most application usages
- 35-micron rating to remove almost all impurities
- Rugged enough for daily use
- Ideal for the professional HVAC technician
- Doesn’t have built-in gauges
- Becomes hot to the touch quickly
Best Mid-Range Model
|Air Displacement||9.0 CFM rating|
|Oil Capacity||16.9 oz.|
|Factory Rating||25 Micron Rating|
|Warranty||90-day refund, 1-year replacement|
When choosing between power, dependability, and price, the best mid-range model vacuum pump may be in order. While the Bestauto vacuum pump rounds out this HVAC vacuum pump review list, it isn’t the bottom of the bunch.
With an impressive 9.0 CFM, this 2-stage vacuum pump delivers where it matters. It is a large unit, with some weight behind it, but that comes with the full 1 horsepower motor and large oil tank (capacity of 16 ounces).
A perfect vacuum at sea level is 0 microns, and this guy will pull 25 microns at any elevation above sea level. With a solid vacuum and impurities removed, you can rest assured that your refill will be pure.
While it doesn’t come with an isolation valve, it has anti-suck back features that ensure your vacuum stays sealed, and recharging is effortless. You won’t have to change the oil often either. The large capacity tank comes with an easy-pour fill spout, and the angled drain plug provides fast emptying so you can get back to work quickly.
For the HVAC professional or homeowner with a lot of projects, the Bestauto vacuum pump will get the job done. To get the best results, make sure you have the proper rated high-pressure charging hoses and a durable manifold. The rest is just a flip of a switch away.
- Large CFM rating (9.0)
- Ideal for daily or constant use
- Rated to 25 microns for clearing out most line impurities
- Difficult to find replacement parts
Types of Vacuum Pumps Used in HVAC
While rotary vane pumps are the most common, you aren’t left with only that option for your vacuum pump. Below is a brief overview of the various HVAC vacuum pump types.
Vacuum generators are quick and reliable, but highly expensive. There are two main valves used with an air inlet and the line inlet.
As air moves through the nozzles at high speed, they get compressed and passed through what is known as a Venturi nozzle.
After passing through the Venturi nozzle, the air expands to fill the chamber and is pushed out of the exhaust port.
This rapid expansion creates a vacuum which then pulls liquid or air through the line inlet.
The vacuum created is high, but doesn’t hold for very long, since air flow must be maintained to continue the vacuum draw.
A diaphragm pump uses a piston and two chambers that are connected to the supply line. When compressed air is added, the piston moves back and forth. This pulls or pushes on a diaphragm connected to either side of the piston. At the top and bottom of each chamber are ball seals.
When the piston moves in one direction, it closes one chamber and opens the other. The open chamber releases the inlet ball seal allowing fluid or air to fill the chamber. The closed chamber releases the outlet ball seal, expelling the fluid or air in that chamber.
The process is repeated on the other side with the downstroke. This series of movements repeats at incredible speeds making the fluid or air only rest in the chamber for a fraction of a second. The result is a constant moving of the liquid or air until a vacuum on the supply line is accomplished. They also hold the vacuum quite well with the ball seals in place on both sides.
Rotary Vane Pumps
These are the most common vacuum pump for HVAC work. The rotary vane pulls air, refrigerant, and moisture from the lines using a motor and impeller. As the rotor turns, the vanes extend to create chambers.
These chambers move the fluid or air through the system and continue until the machine is shut down. Once stopped, the vanes will maintain their position, holding the pressure until released.
Single Stage vs. Two Stage
Motors come in two options, single-stage or two-stage. A single stage motor is responsible for creating the vacuum, pulling in the fluids, and holding pressure. They are less expensive and easy to maintain.
A two-stage motor operates the same way, except the second stage pulls a higher load and maintains a stronger vacuum. Two-stage motors are ideal for lower micron ratings since they can pull out smaller impurities.
How to Use Vacuum Pumps
If you have never used a vacuum pump before, they are simple to operate. You will need the vacuum pump, recovery manifold and hoses, and a recovery tank.
- Place the pump on a sturdy surface where all fittings and valves are easily accessible.
- Attach the low line hose to the blue fitting, the high line hose to the red fitting. The yellow hose will connect to the recovery tank.
- Fill the pump with pump oil. Use the sight glass to check the level.
- Open the valves for the high and low lines on the manifold.
- Turn the pump on and let it run. Use the gauges to measure the vacuum (usually measured in inches of Mercury, or inHg). 30 inHG is ideal for most applications.
- Once the pressure is where you need it, shut the pump off and check the gauges. If the vacuum holds for 10 minutes, you can remove the intake hose from the pump and begin your repairs.
When using the pump on a residential HVAC system, you should attempt to get the vacuum below 100 microns. For automotive applications, the steps are exactly the same, with the exception that you can stop the vacuum anywhere between 500 and 1000 microns.
When working on automotive AC systems, you may need to use an inlet adapter for the R-134a fittings. Double check you have the right connections and hoses before turning on the pump.
Safety & Maintenance Tips
Safety is always something that you should practice when using a vacuum pump. Proper care and maintenance will also prolong the life of the pump and make your job easier in the long run. Here are specific things to do or monitor when using a vacuum pump.
- Always make sure the unit is plugged into a grounded outlet or extension cord.
- Never operate the pump outside its capacity parameters.
- Wear protective gear for hearing, eyes, and gloves when dealing with the pump and chemicals.
- Do not let the pump run out of oil.
- Change the oil when it becomes dirty or when using the pump after a long rest period (about 4 to 6 months).
- Check the unit for oil leaks and repair them as needed before using.
- Vacuum pumps get hot. Do not use near combustible materials or chemicals.
- Never leave the pump running while unattended.
- Store after allowing to cool, in a dry, cool place. Cover if needed to ensure dirt and dust do not contaminate the inlet ports or valves.
People Also Ask (FAQs)
Let’s answer some of the more common questions that arise around HVAC vacuum pumps.
How do I check for vacuum leaks?
When you have your vacuum set, if the vacuum pressure does not maintain for at least 10 minutes, you most likely have a leak somewhere. The best method of finding a leak is to use a leak detector followed by the soap bubble test to pinpoint the leak location.
Why does my vacuum pump consume excessive power?
Most pumps will use a lot of power during startup. If the consumption lasts longer than a few minutes, there could be an electrical problem. You should check that all plugs and electrical wires are grounded and in good repair. If the unit is low on oil, it will get hotter and work harder as well. Check the oil level and fill or replace it as needed.
What should I do if my vacuum pump overheats?
The most likely cause of overheating is low oil or prolonged use. Unplug the pump and allow it to cool completely for a couple of hours. Check the oil level when the pump is warm (not cold or hot) to get an accurate reading of the oil level.
How many microns should a vacuum pump pull down to?
Depending on the application, a vacuum pump should be able to pull to a minimum of 1000 microns. For automotive applications, 500 microns is better. Residential and commercial applications can easily reach sub-100 microns.
How many microns is considered a deep vacuum?
I consider anything below 50 microns a deep vacuum. The average deep vacuum is 35 microns or lower.
Can I use motor oil in a vacuum pump?
No. Only pump oils can be used in a vacuum pump. Any use of other oils will void the warranty and could cause the unit to malfunction, break down, leak or overheat.
What is the difference between HVAC and heat pump?
HVAC units are designed for single purposes. There is a heating side for adding heat into the home, a cooling side for cooling the home, and optional ventilation. A heat pump is two-sided, meaning it can add heat for heating or remove heat for cooling.
What are the accessories that I need to have together with a vacuum pump?
When using a vacuum pump, you will need latex or vinyl gloves to protect your hands, ear protection if your pump is loud or will be close by. You also need a recovery tank and an HCAV gauge manifold and hoses.
When it comes to HVAC vacuum pumps, you have your choice. There are many brands and styles to choose from. The biggest decision you need to make is the CFM and micron ratings you need to perform the task at hand.
Most residential applications will do fine with 3 to 5 CFM ratings. You can also be assured the impurities that cause harm will be removed with anything lower than 100 microns. Single-stage and two-stage motors are an option, but when in doubt, look to Yellow Jacket for the best overall pump to get you started.
Last Updated on July 16, 2021
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