4 Reasons Your Air Compressor Has Water In It
Whether you have noticed water in your compressed air, or have simply heard others complaining about water leaking from their compressor, you are not in the minority: The presence of water is a real issue in air compressors. Even though you may not be a scientist, you are pretty sure that an air compressor is not supposed to spray water.
Why does your air compressor have water in it? Air compressors get water in them due to condensation and wringing of vapor from atmospheric air. There is a bevy of factors affecting the amount of condensation and wringing that occurs, sometimes leading to significant amounts of water byproduct.
Whatever the case, the presence of water in your air compressor can have some unsavory consequences if left unattended. As such, it is crucial to understand what is causing the water to form and how to remove it if you detect its presence correctly.
4 Reasons Water Builds Up in Your Air Compressor
As mentioned in the introduction, water builds up in air compressors due to condensation and wringing of water vapor from atmospheric air. While many are familiar with the process of condensation, which causes dew to form on the grass on a chilly summer morning, here is the reason why it is such a common occurrence in air compressors:
The air compressor pulls air from the atmosphere, known as ambient air, into the compressor through its intake system
An essential characteristic of compressed air is that it cannot contain the same amount of water vapor as the ambient air.
Ambient air squeezes as it enters the compression chamber, sort of like how water gets squeezed from a sponge
additionally, as water vapor escapes while being squeezed, the air gets colder as its volume decreases. This cold air, when pressed up against compressor pipes, will cause dew to form on the pipes that when exposed to the warmer ambient air on the outside.
So, now that you understand the process of how water forms in air compressors, let’s take a look at several different reasons that the presence and amount of water you are observing may differ.
Number One: Your Compressor Is Very Large or Has a High Flow Rate
If you have a very large or extremely high volume air compressor, it is all but a certainty that you will notice significant water buildup.
Flow rate measured by the CFM (cubic feet per minute) or L/S (liters per second), so this with higher airflow ratings will be subject to experiencing large amounts of water byproduct. A fully loaded 75-hp air compressor, with an industrial evaporator, can produce roughly 23 gallons of condensed water over eight hours on a summer day.
As such, given the amount of ambient air that is being squeezed and cooled during the air compressing process for more substantial, industrial-sized appliances, it should come as no surprise that significant water is present.
While condensation will occur for smaller, home compressors as well, it will not be nearly as dramatic and may take several sessions of use before the water buildup becomes noticeable.
Number Two: High Humidity Content in the Ambient Air and High Ambient Air Temperatures
In areas of high humidity, you can certainly feel the water in the air. Take a walk through downtown Miami on a summer afternoon, and you can almost feel the absorption of water in your clothing.
As such, it should come as no surprise that compressed air in areas of high ambient air humidity will give off more water as a byproduct. During the process of squeezing this highly humid ambient air into the compressor motor, the excess moisture will be “wrung out” before compression, causing more water to accumulate in the compressor.
In addition to a high water byproduct in highly humid areas, using your air compressor in hot conditions, even if the temperature is a dry heat, will cause the compressor to give off more water, This is due to increased levels of condensation. In very hot regions, the cooler, compressed air will form a significant contrast against the warmer pipes, leading to the formation of water in the form of condensation. Think about how water forms on the outside of a glass of iced tea on a hot day.
As such, it corresponds that more water byproduct will be present in your air compressor during the summer than during other seasons of the year.
Can This Be Avoided?
Many industrial air compressors have air drying components To combat this issue of high water content in humid ambient air that evaporate the humidity from the ambient air before it enters the compression motor. However, not all personal air compressors have this feature, meaning that there is likely to be a greater air compressor water byproduct in humid locales.
Number Three: Your Air Compressor Produces Very High Pressures
Going back to our earlier example, think about the wet sponge. If you squeeze the sponge very gently, a small amount of water will come out; however, if you squeeze it with all of your force, significantly more water will come out of that same sponge.
The same principle applies to your air compressor. If your unit cut-in point is set high, then a lot more pressure will need to be applied to the air, and you will notice an elevated amount of water given off as a byproduct.
However, if you do not need your air to be so highly compressed, say, for example, in a project to blow leaves from your carport floor, then there will not be as much vapor wrung out of the compressed air.
Number Four: Your Air Compressor Has a High-Pressure Dew Point
The pressure dew point (PDP) is a common way to measure the water content in compressed air. It is the temperature point at which air or gas is saturated with water and begins the condensation process of turning into a liquid state.
Another way to think about this is to the point where the air is no longer able to hold any more water vapor. To minimize the amount of water in compressed air, a lower PDP will produce less water in the system, while higher PDP values will refer to more water vapor in the system.
Check the rating of your specific air compressor, as the value of the PDP for your unit could help explain the presence of water in the compression system.
How to Get Rid of Water from Your Air Compressor
You have probably gathered that the presence of water in an air compressor system is a common occurrence. As such, should water removal not be a regular part of the air compression process?
Water removal is an important part of the air compression process. The buildup of water left unattended can damage your air compressor And will result in negative performance toward the purpose for which the intended design of the compressor.
Therefore, although water byproduct is normal in an air compressor, significant buildup, or water that is present in your air stream is the result of negligence or a malfunction of your air compressor’s drainage system.
The following are some ways to manage the buildup of water byproduct in air compressors. When considering the different options of water removal, it is important to keep in
mind whether you need to use your air compressor for personal or commercial purposes.
Drainage of the Receiver Tanks
When air immediately emerges from the compression pump, it is hot, and any vapor will temporarily remain in a gas state.
Once the compressed air is cooled in the receiver tanks, however, an accumulation of condensation begins to occur.
Therefore, regular drainage of the receiver tanks is crucial to getting rid of the moisture in your air compressor system. In most cases, you can accomplish this through a simple manual drain, but timer-based drains and pneumatic drains are also very useful options.
Mechanical Separator
Mechanical separators are another means of removing water byproduct from your air compressor. Commonly used to separate air and water from oil in combustion engines.
This filter is also known as a filtration water separator and removes large amounts of water from the air supply using centrifugal force. It can get rid of up to 60 percent of all water formed during the compression process, increasing the chances that your compressed air will be dry enough for its intended application.
Over-Compression
Over-Compression Involves the air to be pressurized higher than the intended working pressure. After separation, the over-compressed air is allowed to expand to the normal working pressure for its intended process.
Over-Compression is a very energy-intensive process and may get expensive when attempted at large plants for commercial purposes. As such, over-compression should ideally be an option when dealing with pressurized air in small quantities.
Membrane Drying
Membrane drying involves the selective permeation of the gas components of air to separate the water vapor. As the filtered, wet compressed air enters the compression cylinder, water vapor permeates the membrane coating and collects on the fibers.
Meanwhile, the dry air continues through and does not collect on the fibers, effectively separating the water from the compressed air.
Refrigerated Air Dryers
Refrigerated air dryers may be a necessary option if additional water removal is needed.
Using this process, temperature, pressure, and moisture content are correlated, using a chilling process to take out more vapor. Refrigerated air dryers can typically get you between a 34 and 40 degrees PDP, which leaves compressed air sufficiently dry for most purposes.
Desiccant Air Dryers
Desiccant air dryers are the most effective means of getting pressurized air extremely dry and are used for any commercial purposes, including painting, printing, and instrument use. These high powered dryers can reduce PDP to as low as -100°F.
How Water Can Damage Your Air Compressor
Although the presence of water is common in the air compression process, it can have some serious negative impacts if unattended to.
Untreated condensation in compressed air can cause damage to pneumatic systems, air motors, valves, and any components or machines connected to the air compression unit. Most importantly, if you are using your air compressor industrially, as untreated condensation can lead to expensive product defects.
The following are some specific negative consequences of water that does not properly drain from your air compressor:
Corrosion and rusting in your air compressor’s piping system, as well as similar issues to any equipment connected to the compressor
Damaging of pneumatic controls. Pneumatics is a specific method of engineering in which gas or pressurized air helps perform a function, and these internal controls on your air compressor can be damaged due to excess moisture
Decreased wear and tear due to the washing away of oil and other internal lubricants
Low-quality output in several functions can be especially true for paint guns that rely on pressurized air, as water will dilute the paint and cause it to become discolored and less adhesive
If water is still in the system and a freeze occurs, costly damages can take place due to expanding and cracking of the control lines within the air compressor
Will lead to increased maintenance on the air compressor, which in turn will shorten the appliance’s life
Furthermore, if the air compressor is used in an industrial plant and is just one part of a larger commercial process, excessive moisture in the compressed air system can lead to damaging effects on plant air, instrument air, valves, and cylinders, and air-powered tools.
It is necessary to be proactive and take the necessary steps to keep the compressed air dry, clean, and suitable for any purpose or application to avoid costly and inconvenient shutdowns of the plant.
Can an Air Compressor Get Wet?
There is really no straightforward answer to this question.
It is obvious that the compressor can get wet, and does so very often, through the normal process of compressing ambient air. The water vapor held in ambient air gets wrung out, and condensation occurs within the unit as a result of this air compression process.
If the water were restricted only to the compressor and the receiver tanks, then the air compressor could theoretically be submerged in water and still function. However, this is not a realistic scenario, and getting other elements of the air compressor wet can have some negative effects, as seen when normal condensation byproduct goes untreated.
What Happens If I Use My Air Compressor in the Rain?
The air compressor would most likely be fine in light rain, as the compressor is designed in such a way as to keep all important electrical components dry during a rainstorm. Manufacturers also know that air compressors are likely to be used outdoors and in a variety of conditions, so they are made with heavy-duty construction.
However, significant rain would likely cause some water to seep in where it is not supposed to, causing some electrical shorts that would compromise the function of the air compressor.
If your air compressor somehow got submerged in water, or there was a violent, windy rainstorm that blew significant water into the side of your air compressor, it would be best to leave the unit off until it was thoroughly dried to prevent any issues with the electrical wiring.
In addition to potential electrical issues that may arise from leaving your air compressor out in the rain, the paint becomes at greater risk of rust and corrosion. This would require the same washing and waxing to maintain as does a car’s paint job when faced with heavy moisture.
Why Does Your Air Compressor Have Water In It: Final Thoughts
The normal process of running your air compressor will create water as a byproduct. As normal, ambient air contains water vapor in the form of humidity and condensation is a normal process that occurs in everyday life; this should not be too surprising.
However, four main factors that can influence the amount of water you are
experiencing in your air compressor as a result of these processes, which include:
The air compressor size and flow rate
The air temperature and humidity factor of the ambient air in the area you are working
The amount of pressure your air compressor produces
The value of your air compressor’s pressure dew point
While the presence of water in your air compressor is normal, it should be actively managed, as excess or long-standing water can lead to rust and corrosion, shorts in electrical components, and subpar performance for which the pressurized air was intended. Always drain the tank and inspect for damages before use, remember to test the pressure release valve.
Check out this video on a ruptured air tank.
Therefore, when not in use, Make every effort to keep the air compressor stored in a safe, dry location and to remove all excess water from the receiver tanks.