Whether you're working on your car's AC, or any other AC/Refrigeration system, a HVAC vacuum pump is a must have tool to get the job done correctly. These pumps are designed to remove vapors, gas and other contaminants from an AC or refrigeration cooling system before recharging with refrigerant.
Over the years refrigeration systems have become far more sensitive to moisture, and one of the top reasons for problems occurs when moisture has not been fully removed from the lines. This article will give you step-by-step instructions on how to vacuum your AC lines with a HVAC vacuum pump, and we'll even show you a few of our favorite models to help you find the right one for your needs.
Top HVAC Vacuum Pumps
An air conditioning vacuum pump is used to remove water vapor and air from an air conditioning or refrigeration system.
When an air condition requires repair, there are four steps that take place. They are the following:
- Recover - The refrigerant will need to be removed and collected from the AC system.
- Repair - Once the refrigerant is removed, you'll be able to troubleshoot and repair the system.
- Evacuation - Here's where you'll use the HVAC vacuum pump to make sure the refrigerant system is free from air and moisture.
- Charge and Test - At this point you can fill (charge) the refrigeration system with refrigerant and then do a full test to ensure there are no leaks, and that every thing is working properly.
As you'll see as you begin shopping, HVAC vacuum pumps are available in variety of prices. If you just need the pump for a job or two, you're probably better off purchasing a lower-end model. However, if you're a professional, you'll want one that can handle heavy use and has enough power to do a rapid and efficient job.
Here are a few things to consider:
Cubic Feet per Minute
Cubic Feet per Minute is commonly referred to as CFM and it is arguably the most critical consideration when purchasing an AC vacuum pump.
CFM measures how much air is drawn from the AC system each minute. Vacuum pumps with a higher CFM rating will be able to remove the air faster.
As a general rule of thumb, residential vacuum pumps should have a CFM rating between 4 to 5, where a commercial vacuum pump will require a 6 to 8 CFM rating. That's not to say that you can't use a smaller pump on a larger AC unit, it'll just take a much longer time to get the job done.
Two Stage Vacuum Pumps
A two stage vacuum pump is far more effective since it has two sets of rotors and vanes. For this reason it is able to produce a more powerful vacuum since it will use the exhaust from the first rotor and vane.
A one stage AC vacuum pump is less expensive, and the evacuation process is slower. In addition, the unit operates at a higher dB level (noisier), but ultimately, it'll get the job done.
There are both one stage and two stage vacuum pumps available. You can learn more about the differences here.
Oil Fill Opening
Look for a pump with a large oil fill opening, this will make adding and filling the oil in your pump much easier.
Allows atmospheric air to mix with the exhaust gas. This prevents moisture from condensing in the pump oil and will extend the life of the oil when you are performing wet system evacuations.
Built-in Vacuum Indicator
This handy gauge will let you know when it's time to start watching a micron gauge.
An isolation valve will allow you to isolate the pump from the system while maintaining your vacuum level.
HVAC Vacuum Pumps are relatively small so you'll want it to be portable. Look for one that has a solid and stable base, and that the pump is light enough to be able to move it around.
Watch the Video
The process of vacuuming your AC line-set may sound difficult, but it's actually pretty easy. The goal, of course, is to remove the moisture and air in the copper tubing. Although, we'll refer to this as vacuuming, most professionals call it draw down.
Failure to vacuum your AC line-set could create major issues to your compressor, and if you've ever had to replace a compressor, you know they are extremely expensive.
If this is your first time using an HVAC vacuum pump, you'll likely need to purchase a few additional tools to get the job done. Below you'll find a list of the tools you'll need.
Hoses and Gauges
- Color-coded scales
- Sliding double “O” ring pistons reduce wear
- Long life nylon seats
- Item Package Dimension: 2.0" L x 2.0" W x 2.0" H
- Vacuum gauge with ultra-fine resolution (0.5 to 1000 micron), and a 0-12,000 micron vacuum range for accurate pressure measurement during system evacuation, and high-precision laboratory tests
- Programmable, audible and visual alarm for high and low vacuum indicates when threshold is reached
- Backlit, LCD digital display of seven international units including microns, Pascal, and PSI, and a 1/2-second response time
- Auto shut-off eight hours after alarm activation, and when alarm is disabled
- Built-in hanging apparatus for maneuverability
Valve Core Removal Tool
- The Only Vacuum Certified Valve Core Removal Tool!
- Color : Black
- Vacuum rated to 20 microns
- Easily remove access valve cores for full, unrestricted flow
- MegaSeal cap made from aircraft aluminum and molded neoprene gasket, reliably seals under pressure and vacuum
How to Vacuum Your AC Lines
Once you have your pump and tools, it's time to start the job.
Here's what to do:
Setting-up Your Vacuum Pump
The first thing you need to do is fill the pump with clean vacuum pump oil.
- Unscrew the oil fill cap and add new oil until you reach the fill line, which is typically located in the sight window.
- We recommend using Black Gold Vacuum Pump Oil, but check your vacuum pump for the manufacturer's recommendation. Never use mechanical oils, you should only use oil that is designed specifically for vacuum pumps.
Next, set up your gauge set. We recommend removing the core pins, but it's not necessary.
- Connect the blue gauge and hose to the core removal tool which is attached to the low-pressure service port on your air conditioning unit.
- Connect the red gauge and hose to the high-pressure service port.
- Connect the yellow hose to your vacuum pump.
- Double check that the hoses and gauges are hand tight. A tight seal is important to perform a good vacuum.
Vacuum Your AC Lines
Now that your pump and gauges are set up, it's time to begin vacuuming the AC lines.
- Turn on your vacuum pump.
- Open the gauge valves. On the side of each gauge there's a valve. These valves will need to be open for the vacuum to pull the air out of the AC lines.
- Open the valve on the core removal tool.
- Run the HVAC vacuum pump at full operating speed for at least 20-minutes.
Check the Micron Level
After the AC vacuum pump has run for 20-minutes, it's time to check the micron level.
- Do NOT turn off your vacuum pump.
- Attach the micron gauge by connecting a service hose to the side port on the gauge.
- Turn on the micro gauge.
- Connect the other end of the service hose to the side port of the core removal tool.
- Continue to run your vacuum pump until it reaches 500-microns.
Hold the Vacuum
Once you've reached 500-microns check to see if the vacuum holds.
- Keep the vacuum pump running and close your gauge valves.
- Turn off the AC vacuum pump and remove the yellow hose from the pump.
- Verify that your micron gauge is at 500 microns.
- If there's a leak in the system the micron level will increase, in other words, you will lose the vacuum.
The actual process begins at the 7-minute mark on the video, but there is excellent information in the beginning of the video that discusses the process and tools.
When shopping for a HVAC vacuum pump you'll notice there's a wide variety to choose between. There's quite a few budget friendly pumps on the market today. We look at the ZENY VANE and the VIVOHOME Vacuum Pumps, because they offer a decent quality for the price. If you only need to pull a vacuum occasionally, then they are well worth the money.
However, if you're looking to go higher-end, you may want to consider the JB Industries HVAC Vacuum Pump. It's a solid pump without a lot of the professional level features that are often never used by DYI'ers.
Of course, if a vacuum pump will be a tool you'll use frequently or you're a professional, then you should consider investing in a professional grade pump. The Field Piece and Yellow Jacket AC Pumps are excellent picks. Let's take a deeper look at each:
ZENY VANE Economy Vacuum Pump
The ZENY VANE Economy Vacuum Pump is a single stage, 3.5 CFM AC Vacuum Pump. This is a great choice for those who need a pump for an occasional job, but doesn't want to invest a lot of money. Don't expect a lot of bells and whistles, but for the price it's hard to go wrong, and a quick glance at the reviews shows there's plenty of happy owners.
The ZENY VANE has an all-copper 1/4 horsepower direct drive motor, with an internal high volume cooling fan which allows it to operate for long periods of time. The heavy-duty aluminum alloy pump casing keeps it light weight, yet provides protection.
There's an easy-to-see oil sight glass where you can monitor the oil level and quality while the vacuum pump is running.
Watch the Video
VIVOHOME Vacuum Pump
The very popular VIVOHOME Vacuum Pump is a great choice for first time vacuum pump owners. This unit comes with everything you need to get started at pulling a vacuum. It even has a carry bag to keep it all together! The kit includes a manifold gauge set, color-coded hoses, a leak detector, and a bottle of oil.
This 4 CFM single stage rotary vane vacuum pump by VIVOHOME has a die-cast aluminum housing which makes it lightweight, yet durable. The 1/3 horsepower motor delivers 1440 RPM, and the pump itself has an oil capacity of 330 ml.
There are two intake fitting sizes: 1/4-inch and 1/2-inch, and the pump has a micron rating of 150. The oil sight glass is easy to read and shows the condition and level of the oil.
JB Industries DV-6E Eliminator
The 6 CFM JB Industries DV-6E Eliminator Vacuum Pump is considered by many to be one of the best vacuum pumps on the market for the money. JB Industries removed many of the premium features from their Platinum pump series which are not needed by the average user. But don't let that fool you, this is a high performing, solid pump that will get the job done with the quality you expect from JB Industries, you just won't need to pay a premium price!
The DV-6E Eliminator Pump holds up to 25 ounces of oil, and has a large visible sight glass where you'll be able to monitor the level and contamination of the oil. The brass intake ports has a 1/4-inch and 3/8-inch connection to match a variety of hose and manifolds.
It comes with the standard JB Industries 1/2 horsepower, 1725 RPM capacitor start motor, and has a thermal overload protection feature for added safety. It is a 2 stage direct drive pump that can achieve a deep 25 micron vacuum.
Watch the Video
Fieldpiece VP67 Vacuum Pump
The Fieldpiece VP67 Vacuum Pump is a dual stage, 6 CFM vacuum pump that is designed for serious work. Built to last, with well-thought out features, this high-end pump is a must have if you're a professional or a die hard enthusiast. Its lightweight design, rugged build, and best-in-class flow rates allows you to get the job done fast. It's fair to say that this HVAC vacuum pump is unique in design and effective in performance.
The Fieldpiece VP67 has four intake ports which provide clean and easy hose management. It has a 1/4-inch port, two 3/8-inch ports, and one 1/2-inch port in an easy to reach location. The side exhaust port is threaded and designed to be attached to a garden hose, should you want to redirect the exhaust fumes.
But what really sets this AC vacuum pump above the rest is the RunQuick Oil Management System. The backlit window allows you to view the pump oil to monitor the level and condition of the oil. When it's time to change the oil, it's quick and easy, not to mention you can add oil while the pump is running so you don't lose the vacuum.
Watch the Video
Yellow Jacket Vacuum Pump
If you're looking for a professional grade AC vacuum pump, you really need to check out the Yellow Jacket 93600 Bullet Vacuum Pump. Yellow Jacket is a trusted manufacturer of vacuum pumps and a favorite among HVAC professionals.
The Yellow Jacket 93600 is a 7 CFM, 2-stage rotary vail oil sealed vacuum pump which pulls down 25 microns or better. It has a large, easy to view oil glass that allows you to check the condition and level of your pump oil. Changing oil is quick and easy, with the wide and deep oil fill port (which also functions as the exhaust when the pump is operating) and the brass plug drain fitting. The bullet holds nearly an entire quart of oil, yet it can be fully drained in just 60-seconds.
There are three intake fitting sizes: 1/4", 3/8", and 1/2" that attach to an internal check valve which prevents oil from being sucked back into the pump.
If you're a professional, or simply need a professional grade vacuum pump, the Yellow Jacket 93600 Bullet is an excellent choice.
Watch the Video
Last update on 2022-11-23 / Affiliate links / Images from Amazon Product Advertising API