This vacuum pump supercharges everything in its path. Lasts for a long time.
You need an adapter if you have AC systems you're using.
Affordable pump that can be used over and over again. Truly an excellent find if you are focused on price.
The pump is smaller than other models.
The price is affordable for most people. Can be used for all kinds of vacuum-powered needs.
It takes time to get used to. Be patient when using it.
The vacuum pump has a so-so price. Its power is average.
It isn't as well-engineered or strong as other pumps.
We purchase every product we review with our own funds — we never accept anything from product manufacturers.
A vacuum pump is basically an air compressor that runs backward. Instead of forcing air into an enclosed container, the vacuum pump sucks and pulls air or other gases out of an enclosed container. The better and stronger the pump, the more air it can pull out, and the lower the resulting gas pressure will be in the container.
Vacuum pumps are versatile tools that, while intimidating, are fairly simple to use. After you’ve used one successfully a time or two, you will likely be confident in using this handy tool. Vacuum pumps may be used for repairing AC units, preserving food, and a number of other uses.
Of course, you do have to get the right vacuum pump for your needs. Are you a weekend warrior who only needs a pump now and then, or do you work with vacuum pumps day in and day out? Keep on reading our buying guide, and we’ll walk you through the decision-making process, so you’ll wind up with the right one for you.
Vacuums, whether they are in engines, machines, or enclosed containers of any kind, are measured in microns. A micron is 0.001 millimeters. Air pressure is normally measured in the number of column inches of air. Microns are much smaller, so an air pressure of 40 microns would equal an air pressure of 0.0015748 pounds per square inch.
That doesn’t sound like much — and it isn’t. The lowest air pressure the human body can withstand before the blood begins to boil is 0.89 pounds per square inch. Forty microns of vacuum, in many cases, is the high end of the vacuum a vacuum pump can create. Many pumps can lower that number even more. Modern appliances have requirements for a near-absolute vacuum during the repair and recharge process, so you need to know how much vacuum will be required for the systems you’ll be working on.
You should consider how much you’ll be using the vacuum pump. If you’re only using it once or twice a year, almost any model will satisfy your needs. If you need a vacuum pump daily at work, you’re going to need a very robust model that can be easily carried from one location to another.
If you’re using to for vacuum storage of non-perishable items such as blankets and clothes, or if you need to vacuum-pack food for long-term storage, a diaphragm pump would be suitable for you.
For working with any kind of refrigerant, a diaphragm pump won’t be appropriate. You’ll need a rotary vane pump.
The nature of the work being done by vacuum pumps requires an all-metal construction, except for the base, which is generally made of ABS plastic with rubberized feet. Aluminum is the most common metal used in vacuum pumps for its low price, although some heavier models use steel.
The more horsepower the engine has, the stronger the pull it will have in drawing gases out of an enclosed container or system. Smaller horsepower engines can achieve the same results as larger horsepower engines over a longer period of time. If you’re not in a hurry, save yourself some money by purchasing a pump with 1/4- to 1/2-horsepower engine. If you need more power to get the job done quicker, you should look at a 1 horsepower motor.
Most vacuum pumps have a carrying handle for portability, but some are intended to be installed and left in place. You should have a good idea of which design is right for your needs before you buy.
Directly related to portability is the weight. Because of their all-metal construction, vacuum pumps tend to be heavy even though many are made from aluminum. A lightweight pump would weigh in at around 11 pounds, while heavier ones may reach 35 pounds.
There are some crucial differences between diaphragm and rotary vane pumps you should be aware of before you make your selection.
A diaphragm pump has a rod connecting a flexible diaphragm to a rotor. As the engine turns, it turns the rotor which moves the connecting rod up and down, moving the diaphragm with it. As the diaphragm is pulled down, it sucks gases in through the intake. When the rotor moves to the opposite side of the cycle, the rod begins pushing up. A check valve in the intake closes and the check valve in the exhaust opens to allow the gases to be expelled.
Diaphragm pumps don’t require oil, so the maintenance needs are low. Because diaphragms are made of a flexible material, they aren’t suitable for acidic or solvent vapors. Depending on how much a diaphragm pump is used, the diaphragm may have to be changed on an annual basis. Finally, diaphragm vacuum pumps can’t achieve the same micron levels as rotary vane pumps. Generally speaking, however, they are less expensive.
A rotary vane pump uses a vane that sweeps the sides of a cylinder to pull gases in through intake then expels them through the exhaust. Due to the construction of the rotor and vanes, check valves aren’t required. However, special oils with low vapor pressures are required for lubrication of the vanes and cylinder walls.
The normal operation of rotary vane pumps uses the oil at a steady pace because each time the vanes sweep past the exhaust port, some of the oil is expelled along with the gases. It’s a function of the way the pump operates and cannot be avoided. In order for the pump to operate, you’ll need to keep an eye on the oil levels and constantly refill it. Rotary vane pumps can produce excellent micron numbers but at a greater cost than diaphragm pumps.
A single-stage vacuum pump has less complicated controls and only one set of vanes. The faster the motor runs, the greater the suction. A dual-stage pump has more complicated controls because it has two sets of vanes that give you the option of volume versus pressure.
People assume that a dual-stage pump must be better than a single-stage one, but in truth, the differences are minimal. Both types can achieve the same vacuum, although the time required may be slightly longer for a single-stage pump. Maintenance and oil requirements, however, are the same.
Vacuum pump oil: FJC 2200 Vacuum Pump Oil - 1 Quart
Rotary vane vacuum pumps use a lot of oil. Make sure you have enough with this FJC 2200 Vacuum Pump Oil that comes in one-quart jugs equipped with an easy handle for carrying and pouring.
Pressure gauges: OrionMotorTech 5FT AC Gauge Set
A pressure gauge set is essential for using your vacuum pump. This one from OrionMotorTech has 5-foot hoses that are color-coded for easy identification, high and low-pressure gauges, and all the couplers you’ll need.
Inexpensive: For below $100 are diaphragm or single-stage rotary vane pumps. Some low-quality double-stage rotary vane pumps may be available for this price as well.
Mid-range: The majority of vacuum pumps cost between $100 to $300 and may be single- or double-stage rotary vane pumps.
Expensive: Above $300 is the high price range for vacuum pumps. These are generally steel or all-metal high CFM pumps that are almost exclusively double-stage rotary vane pumps.
If our top picks didn’t quite meet your needs, we have a few other recommendations to consider.
We like the economy-priced 3.5 CFM Single-Stage Rotary Vane Pump from ZENY. This is a lightweight, single-stage vacuum pump with an all-aluminum casing and a rubberized base. It has a 1/4 HP motor and an oil capacity of 320 milliliters. There is a sight glass to you can keep an eye on the oil levels, along with a direct drive motor for easy start starting.
We also like the VIVOHOME 110V 1/2 HP 5 CFM Dual-stage Rotary Vane Vacuum Pump. It is an inexpensive pump for automotive air conditioning, refrigeration, and HVAC work. It includes a 500 milliliter bottle of oil. The oil sight glass is marked with minimum and maximum settings to ensure you use the right amount of oil.
Q. What does CFM mean on these pumps?
A. It stands for “cubic feet per minute,” indicating how many cubic feet of air the pump can move in one minute.
Q. How long should a vacuum pump take to pull all the air out of an AC unit?
A. The average length of time is between 15 and 30 minutes, but it is always better to err on the side of caution and let the pump run for a full half hour.
Q. What’s the difference between a vacuum and a vacuum pump?
A. While a vacuum is generally used for sucking up dirt and debris, a vacuum pump is designed to remove the gas (or air) from an enclosed container to create a space free of as — a vacuum. They’re used for HVAC repairs and recharging, automobile AC systems, vacuum packing, and refrigerator repairs.