Tag: humidity

Rule #1 – Always Look Cool

Published on by Brian FarnoLeave a comment

The past two weeks here in Cincinnati have reminded me just what humidity is all about. While the static charge in my garage at home is at an all-time low, the humidity is enough to make me wish I had gills to breathe. Even rucking before work has become a rather sweaty event. When I am rucking, one of the 4 Rules of Rucking is, #1 Always Look Cool. This is an idiom as in don’t let people see you sweat. If you are stressed, just stay cool, keep a level head and look the part. A good pair of aviators always helps to hide what your eyes can’t.

Then I open my garage fridge, because every Midwesterner has their old kitchen fridge in the garage, right? Grab a nice cold aluminum can out. And before I can put it in a thermal insulating housing, I see the condensation of the humidity forming on the aluminum. This makes me think of some of the electrical panels I encountered during my time in machine shops.

I once approached a vertical machining center whose spindle chiller, with a thermo-couple failure, had been cooling the spindle continuously during the summer months. This spindle looked like the ice-cold aluminum can I had sitting out on my workbench yesterday. Fully covered in condensate from the humidity in the air. Condensate collected on an aluminum can and leaving a ring of water on a workbench is one thing. Water running down a high-speed spindle and causing issues with a dry machining process is another. This also reminded me of a recent call where a new customer wanted help sizing a Cabinet Cooler System to replace an air-to-air heat exchanger that had failed. When walking through the information needed to size the panel, I reached the Internal Temp Desired field, and there was a pause. While I thought maybe they were checking their notes, they came back with 72°F. I wrote down the value on my notepad, then asked, “That’s oddly specific. Is there a piece of equipment that alarms out over 72°F that we are trying to protect?” The response I received was no. So I asked what the need was for this low set point.

I dug further with them, and it turned out that’s what they kept the engineers’ office set for in the summer, so they thought my question was odd and figured, if they are comfortable there and their computer on their desk operates well, then it must be a good temperature. This is not an incorrect statement. The control cabinet for the machine would operate just fine at 72°F; however, all the electronics that were in the panel were rated up to 104°F before they overheat, so it doesn’t quite make sense to extend the cooling capacity needed to reach that 72°F requested set point. Once we talked this over, we settled on the standard of 95°F for the internal set point with the understanding that by using a thermostatically controlled system, they could adjust it down lower if they really wanted to. In the end, we saved them some energy by sizing the Cabinet Cooler System to meet the demands of their industrial electronics, not what makes a person feel comfortable.

This isn’t always the case; occasionally, there is a panel that requires a low maximum temperature in order to keep a critical piece of equipment stable. This is why we ask the questions to validate any concerns with the data we are viewing as Application Engineers. This is also why we have built in a number of warnings/alerts on our Online Cabinet Cooler Sizing Calculator.

If you have a panel that needs to be cooled, the online calculator has fields for all the information we need. If you want to walk through the math behind the calculator and talk through the reasons we ask for the information that we do, you can either call, email, or even live chat with an Application Engineer, and we will gladly walk you through our process and the math to determine which Cabinet Cooler System is right for your needs.

Brian Farno, MBA – CCASS Application Engineer

BrianFarno@EXAIR.com
@EXAIR_BF

Freebies! EXAIR AC Sensor Pens Are IN!

Published on by Brian FarnoLeave a comment

Here at EXAIR we always have a promotion going. This time of the year, static electricity is running rampant. I know over the weekend at my youngest daughter’s basketball game, I wished I had a Gen4 Ionizing Bar to knock down the static on the dry-fit coaching shirt I had clinging all over myself. Then, oddly enough, I found myself later in the day needing my A/C Sensor pen to check whether an outlet had voltage coming into it because I was going to change the circuit it was operating on.

If your facility has dry ambient conditions right now in these winter months, and you are starting to struggle with sheets clinging together, packaging material clinging to products, or operators complaining of nuisance shocks from aspects of their daily tasks, we have a product that can help. Best of all, we have a promotion to deliver a FREE A/C Sensor pen with any EXAIR Static Eliminator purchase.

Whether you need a fixed solution like the Gen4 Super Ion Air Knife, Intellistat Ion Air Nozzle, or Gen4 Ion Air Cannon, maybe you need something that can travel from one workstation to another or is handheld like our Gen4 Ion Air Gun Kit, or the Intellistat Ion Air Gun. Maybe you don’t have compressed air available, like I didn’t at the basketball court. As long as you have access to a standard 120 VAC 3 prong US plug or 230 VAC, then you can use one of the Gen4 Ionizing Points, a Gen4 Ionizing Bar, or even the Varistat Bench top Ionizer. See the page at the link below for all the offerings and make sure you use the promotional part numbers to get the free A/C Sensor pen which can be used for electrical troubleshooting for free!

If you aren’t sure which static eliminator is going to be the best fit for your current application, that is what I and the entire Application Engineer team are here for. We all have knowledge and experience with the products and a large variety of backgrounds so that we can help determine the best path forward for you and your team, so contact one of us today.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

Dew Point and Water in Compressed Air: Understanding the Effects

Published on by John BallLeave a comment

In systems, it is important to understand the type of medium that is being used.  For most EXAIR products, this will be compressed air.  As the air compressor draws in ambient air, it also brings in dust, contamination, and moisture into the system.  If untreated, the pneumatic system will have to contend with these foreign “invaders” that will affect the performance of your pneumatic devices.  One of the most common problems is water.

Water enters the compressed air system from the water vapor already present in the ambient air, which is referred to as the dew point or relative humidity.  When you take ambient air and compress it, the amount of “elbow room” for the water vapor decreases.  This causes the water vapor to condense and create liquid water.  It would be similar to a water-soaked sponge.   As you compress it with your hands, the sponge will not be able to hold on to the water.  Similarly, as the air is compressed, water will start to form and fall out into the compressed air system.  Water is a by-product of a compressed air system.

Visual depiction of the impact of water vapor contained amongst air particles and how this reduces available volume during compression.

The definition for determining if liquid water is present in your system is called the pressure dew point.  Dew point is the temperature at which water vapor will condense and form water droplets.  If the dew point temperature and the air temperature are equal, then the air is considered 100% saturated (water vapor will start to condense to form water droplets).  In compressed air systems, air dryers are used to reduce the dew point temperature.  This means that unless the ambient temperature falls below the dew point temperature, water vapor will not condense into a liquid state.

There are two major types of compressed air dryers; refrigerated and desiccant.  The refrigerated air dryers are the most common, and the dew point is measured at about 39oF (4oC).  So, unless the air temperature gets close to freezing, i.e., the piping system that goes outside in cold weather, water should not be present.  Desiccant air dryers can achieve dew points as low as -40oF (-40oC).  This compressed air is very dry and can be used for medical systems, food and beverage processing, and instrument air.  The reason is that bacteria cannot survive in compressed air that is that dry.  The other types are dewpoint reducing systems, which include membrane and deliquescent dryers. 

Good engineering practice calls for point of use filtration and moisture removal, such as that provided by EXAIR Filter Separators.

For most pneumatic devices, a Filter Separator with an auto-drain should be used as a minimum amount of protection.  Even with systems that have compressed air dryers as described above, they are mechanical devices.  So, failures can occur.  You should review your compressed air system to ensure that your pneumatic system, including EXAIR products, is operating at peak efficiency.  This will include your supply system, compressed air leaks, and blow-off devices. 

Moisture-laden compressed air can cause issues such as increased wear on the pneumatic tools, the formation of rust in piping and equipment, quality defects in painting processes, and frozen pipes in colder climates.  Regardless of what products you’re using at the point-of-use, a compressed air dryer is undoubtedly a critical component of the compressed air system.  Providing clean, dry air to EXAIR Products or other pneumatic devices will help to extend the life of your equipment.  If you wish to discuss more about your compressed air system or how EXAIR can provide a more efficient way to use that compressed air, an Application Engineer will be happy to assist you.

John Ball
International Application Engineer


Email: johnball@exair.com
Twitter: @EXAIR_jb

Refrigerated Air Dryers

Published on by John BallLeave a comment

Whenever air gets compressed, it reduces the space for the water molecules to remain as a vapor; which causes condensation.  For this, compressed air dryers are an important part of a compressed air system.  They are designed to remove moisture to prevent condensation further downstream in the system.  The three main types of dryers are refrigerated, desiccant, and membrane. For this blog, I will cover the refrigerant-type compressed air dryers.

Compressed air dryers are rated with a dew point rating.  A dew point is the temperature at which the air has a relative humidity of 100%.  Since the air cannot become more saturated with water than 100%RH, water will condense and fall out like “rain”.  You can see this effect during the cool mornings when dew forms on the grass.  Compressed air dryers are designed to reduce the dew point temperature of your compressed air.  For a refrigerant type, they are near the dew point temperature of 38oF (3oC).  Like a refrigerator, they use refrigerant to cool the compressed air.  We cannot go below this temperature as it could form ice inside the dryer.  But, as long as the ambient temperature does not go below 38oF (3oC), liquid water will not be present in the pneumatic system. 

There are two main types of refrigerated air dryers; cycling and non-cycling.  Cycling type refrigerant air dryers will cool a liquid mass, generally a glycol-water mixture, to a set-point and turn off.  The liquid will go through an air-to-liquid heat exchanger to remove the heat from the compressed air.  Referring to the cycling action, when the liquid mass goes above the set point, the refrigeration system will restart and cool the liquid mass again.  The cycling refrigerant air dryers are more expensive, but they are more efficient. 

Non-cycling refrigerant air dryers are more common.  The refrigeration system continues to run through an air-to-air heat exchanger to cool the compressed air.  It is similar to your AC system in your car.  With this type of system, they are more susceptible to the environment, i.e., temperature, elevation, and humidity.  So, adjustments are required for proper installation. 

With both types of refrigerant dryers, the internal compressed air section is very similar.  They will have a filter separator to remove the liquid that is created from the condensation from the cold temperatures.  They also have an additional air-to-air heat exchanger.  This will provide two important features for the refrigerated air dryers.  As the cold air leaves the refrigerant section, it helps to cool the incoming compressed air.  This will make the system more efficient.  And as the hot incoming compressed air helps to warm the cold air leaving the dryer, it will stop the condensation of liquid water on the outside of the pipes.  Like the dew forming on the grass during cool mornings, the same will occur with the compressed air piping system. 

Moisture-laden compressed air can cause issues such as increased wear on the pneumatic tools, the formation of rust in piping and equipment, quality defects in painting processes, and frozen pipes in colder climates.  Regardless of what products you’re using at the point-of-use, a compressed air dryer is undoubtedly a critical component of the compressed air system.  Delivering clean, dry air to your EXAIR Products or other pneumatic devices will help to ensure a long life out of your equipment.  If you wish to discuss more about your compressed air system or how EXAIR can provide a more efficient way to use that compressed air, an Application Engineer will be happy to assist you. 

John Ball, CCASS


Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb

Photo: Grass morning dew by RuslanSikunov.  Pixabay License