Fundamental Modes of Heat Transfer

Generally I like to write about cool stuff. Whether it is a new product like our TurboBlast Safety Air Gun, an application that really helped cool down a process for a customer, or even something cool I have done like a GORUCK event or training. Well, today is not one of those days, today we are going to talk about the opposite of cool … HEAT and more importantly the methods it is transferred.

1 – Energy Transfer – Heat

The process of how heat is generated all starts with a conversion of energy. Whether it is friction, or converting energy to light, or even converting energy to a different voltage through something like a transformer. No matter how it is generated, heat will begin to transfer. On the molecular level, atoms are storing the energy which will cause electrons to enter into an excited state and rapidly switch between shells. When the electron returns back to a lower shell (closer to the nucleus) energy is released; the energy released is then absorbed by atoms at a lower energy state and will continue until the thermal energy is equal between the two objects. Heat has four fundamental modes of transferring energy from surface to surface and they are as follows:

Conduction
Conduction can also be referred to as diffusion and is the transfer of energy between two objects that have made physical contact. When the two objects come into contact with each other thermal energy will flow from the object with the higher temp to the object with the lower temp. A good example of this is placing ice in a glass of water. The temperature is much lower than the room temperature therefore the thermal energy will flow from the water to the ice.

Radiation
Radiation is the transfer of thermal energy through empty space and does require a material between the two objects. Going back to the how thermal energy is released from atoms; when the electron returns to a lower energy shell the energy is released in the form of light ranging from infrared light to UV light. Energy in the form of light can then be absorbed by an object in the form of heat. Everyone experiences radiation transfer every day when you walk outside; the light from the sun’s radiation is what keeps this planet habitable.

Convection
Convection is the transfer of thermal energy between an object and a fluid in motion. The faster the fluid moves the faster heat is transferred. This relies on the specific heat property of a molecule in order to determine the rate at which heat will be transferred. The low the specific heat of a molecule the faster and more volume of the fluid will need to move in order to get full affect of convection. Convection is used in modern ovens in order to get a more even heat through out the food while cooking.

Advection
Advection is the physical transport of a fluid from point A to point B, which includes all internal thermal energy stored inside. Advection can be seen as one of the simpler ways of heat transfer.

No matter how the heat is transferred to an object, if it needs to be cooled there is a good chance that one of our Application Engineers has approached a similar issue and can help. To discuss, contact us and we will walk through the best method to eliminate the heat you need to.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

1 – “Energy Transfer – Heat” by Siyavula Education is licensed under CC BY 2.0

Overheating Cabinets Are Bad. Cabinet Cooler Systems on Promotion Are Good!

In southwest Ohio we are currently experiencing 88°F. And we have begun to see increased numbers of inquiries for Cabinet Cooler Systems to keep control cabinets cool. This comes with the territory of approaching summer here in the northern hemisphere, and elsewhere it is due to new machines going into areas of a facility where it is constantly hot and dirty. It seems like the perfect time to offer up some free stuff with our Cabinet Cooler Promotion.

That’s right, order any of the Cabinet Cooler® Systems listed and receive a free A/C Sensor Pen. This pen has saved me from getting shocked many of times around my home.   Without it of course, I find myself guessing I turned the correct breaker off and, as soon as I touch the outlet I am working on I get hit with 110V. This sensor is helpful to locate the presence of voltage and avoid getting shocked.

We are here to assist your choice of Cabinet Cooler system and to provide a very fast solution to the downtime you are experiencing. We manufacture Cabinet Cooler systems from 275 Btu/Hr through 5600 Btu/Hr with NEMA 12, 4 and 4X integrity as well as Hazardous Location. If you don’t know what Cabinet Cooler System you need, take a look at our new Cabinet Cooler Calculator or the form below. It can be found on our site, get the information and call, fax, e-mail or live chat with an Application Engineer to get a quick and accurate response on what amount of cooling your system will need.

Sizing Guide

Over our thirty years in business we have also seen many companies who only experience a short span of seasonal heat and have found that 2000 Btu/Hr is enough refrigeration to offset summertime heat load, in most cases. Choosing a model with a thermostat control will turn the cooler on and off as needed and minimize compressed air use. Cabinet Cooler systems are in STOCK and ship same day for domestic and Canadian orders received by 3:00 pm EDT. We can get your cabinet cooled FAST and eliminate your heat related problems. Cabinet Cooler systems are shipped ready to install through a standard electrical knockout. There is no waiting for oil to settle back into the compressor motor, no mounting templates required or huge holes to cut into your cabinet. Cabinet Cooler systems have no moving parts to wear, making them rugged and lasting in your hot environment.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

How Fast Can I Get My Return On Investment

Whenever an EXAIR product is sold to another business there is ultimately a question from a customer whether they know it or not. That question is very often, how fast will this product pay itself back in production gains, air savings, or decrease in downtime. One of the ways we offer this information is through our calculators.

The easiest method to determine how fast an EXAIR Engineered Solution will pay itself back is by knowing a few variables and then plugging them into our simplified Air Savings Calculator on the EXAIR site.

The Variables:
1. Current Customer Consumption (SCFM) or (SLPM) – We need this to have the baseline, it isn’t always easy to know off the top of your head so we offer items like the Digital Flowmeter or even the ability to send the product to us through the Efficiency Lab for a free diagnosis of consumption.

2. $ Cost of EXAIR Product – This is easy, you can even add in other known project costs to this that you want factored in for the return on investment. The more you add, the less it becomes a simplified ROI. Basic cost of the EXAIR product that is being installed is the best to keep it simplified.

3. EXAIR Product Consumption (SCFM) or (SLPM) – This can easily be obtained from our website or our Brain Trust, I mean Application Engineers who are always eager to talk about air consumption and other technical details. To really determine this we just need to know the operating air pressure and the model number.

4. $ Cost of compressed air/1,000 Cubic Feet – This is a value that may be known by the on-site utilities team, if not a good industry standard for the Midwest is $.25 USD. This has come assumptions on your kWh cost of energy and compressor efficiency. Again, if you want to dive deep into this, reach out to our Application Engineers, we are here for a reason.

That’s it, with those values input you can get a break down on how much air, and money you are saving and a simple payback in days of operation.

If you have questions on the math behind this, or how to determine/factor in some more information, contact one of the team members here and we will walk you through the best options to decrease your payback time and increase your efficiency.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF


Adjustable Vacuum Levels for Different Materials from These Vacuum Generators

When determining a single vacuum generator that will fit a variety of demands, whether it be varying weights, surface finishes or materials, the Adjustable E-Vacs can make quick work of the task at hand. This minimizes the number of parts needed for a variable product line. It also means each application can be adjustable as well. So why would this be needed?

Let’s look at a custom woodworking shop. They could be lifting slabs of lumber that may be rough cut, maybe they are lifting a smooth epoxy river slab, or even sheet of MDF. Each one of these materials will require some adjustment on the vacuum end. The reason being the surface finish and porosity of each material is considerably different.

MDF, expanded out as Medium Density Fiberboard is a common material for woodworkers to use. This material looks and feels smooth and fairly solid. The trick is, it is actually a porous material. You can hook a vacuum hose to one side of it and hold a piece of notebook paper to the other side because the vacuum flow will be pulling through the MDF. This presents a problem when trying to use vacuum to pick and place the board. You will need a higher vacuum flow in order to compensate for the leakage of air when pulling a vacuum. An epoxy coated slab on the other hand, is generally a smooth surface that is non-porous and will require less vacuum flow.

Adjustable E-Vac: How it works

The greatest benefit to the Adjustable E-Vac is being able to easily adapt to meet the needs for both of these materials with a tool-free adjustment. A great example of this is in the video below.

If you would like to discuss which of the Adjustable E-Vacs is right for your variable application, reach out an Application Engineer today. We can all help you determine which of the 4 Adjustable E-Vacs will best fit your application and even help you understand what kind of adjustments will need to be made.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF