Absolute Zero

Gary Reecher sends me information from time to time. One of the nice things about having a network of  friends is that you don't have to know everything, you can use the network's collective knowledge. I am blessed with a good network. Gary recently sent me this on a show he saw on NOVA about absolute zero and I wanted to pass the information along. It is rare to find television that is both entertaining and educational, but NOVA usually accomplishes that. What follows is the text  of Gary's message.

Many times when one watches television it is to be entertained. Occasionally a program not only entertains but educates and enlighten. That is the instance of NOVA's Absolute Zero series. 

Our local PBS channel re-aired this 2009 2 part series. And here is an outline of the series. 

NOVA brings the history of cold to life with historical recreations of great moments in low-temperature research and interviews with historians and scientists to reveal how civilization has been profoundly affected by the mastery of cold.

Hour one of the program (The Conquest of Cold):

• reports on the pioneering experiments done by Robert Boyle to understand what cold was.
• presents how the first temperature scales were determined by Daniel Fahrenheit and Anders Celsius.
• recounts how Guillaume Amontons first came to speculate that cold had an absolute limit.
• explains how scientists came to understand what heat and cold actually were, including the incorrect caloric theory proposed by Antoine Lavoisier.
• reports on the first industrialization of cold through ice sales.
• details how experiments on the steam engine led to the development of artificial refrigeration.
• profiles how Clarence Birdseye and Willis Carrier harnessed the cold to create frozen foods and air conditioning.

Hour two of the program (The Race for Absolute Zero):

• features the race between nineteenth-century scientists James Dewar and Heike Kamerlingh Onnes to become the first to liquefy hydrogen, the last of the so-called permanent gases.
• notes how unexpected events in the study of cold led to new areas of research, including superconductivity and superfluids.
• details how Albert Einstein came to predict that a new state of matter—one that behaved according to quantum mechanical rules—could be produced at temperatures just above absolute zero.
• shows how particles would change into overlapping waves in this state of matter, known as the Bose-Einstein condensate.
• details the race among scientists to create this condensate.
• describes how one scientist found a way to slow down the speed of light.
• reports on research being done to develop quantum computers.
• shows how far down the scale scientists have traveled and explains why reaching absolute zero is not possible.

If one is interested in the history and development of refrigeration I would give this series a 2 thumbs up.   

More information is available http://www.pbs.org/wgbh/nova/zero/ including instructor resources for using this program.

Christmas Spirit

This will be a short post. I ran across this listing of organizations that help people in creative ways by redirecting resources we already have and i had to share it. I believe these good people have the right idea. Merry Christmas!

http://www.cnn.com/2010/LIVING/12/23/cnnheroes.12.ways.of.giving/index.html?hpt=C1

The Treasure Hunt

Although this blog normally features articles on air conditioning instruction, I am taking the liberty of writing on the current Christmas Season in this one. It is nearly Christmas and many of us are neck deep in the annual last minute treasure hunt that takes place this time of year. We scour adds and the internet looking for elusive gifting treasure. We sacrifice time, health, and wealth in an effort to secure those must have gifts in our annual treasure hunt. The tension is heightened because we compete against each other; there are only so many baby bobble heads to be found! Even if you are not particularly religious, you probably have heard the famous verse from Luke 12:34 “For where your treasure is, there your heart will be also.” The normal interpretation of this verse is to point out that you invest your time and money in what you really love. I think most people recognize the truth in this statement even if it can make us uncomfortable. However, I would like to turn this around a bit and suggest  that your heart will locate your treasure for you in this mad scramble treasure hunt. What would you miss most in your life if it were suddenly taken away? The answer is probably not something, but someone. Hopefully several someones. Afterall, why are you trying to locate the baby bobble head? To see the look of joy on someone’s face. So in the din of the treasure hunt let your heart guide you to your treasure. My treasure greets me in the morning, sings in the choir, plays in the marching band, and studies at Vanderbilt. I am a wealthy man!

Cool Toys for HVAC/R Instructors!

Document camera? I thought this thing was an air conditioning component magnification system! I have been learning to use my new toys this quarter. I was given a document camera and video projector for my class room. Many people know these things as Elmos because that is who developed the first ones. If you are unfamiliar with them, they are able to zoom into a document placed on them so that you can project it to a screen using a video projector. That is OK, but what I use it for is projecting images of components and tools. Put a defrost board on it, zoom into the defrost setting jumpers, and show how to set the time on an electronic time-temperature defrost board. Look at the color bands on resistors. Ohm the coil out on a relay and show the meter as you ohm the coil out. Wire a simple circuit and operate it, then measure the voltage drop across the switch. Disassemble a TEV and show the difference between an internal and external TEV. Show the difference between the wire gauge of the run and start winding on a split phase motor. I am just getting started, but I think you get the drift. You can show detail in real time and everyone can see and follow what you are doing even better than if they were standing beside you. Having drawn many extemporaneous works of art on the white board, I still sometimes revert to my older chalk and talk methodology. Elmo helps there as well. If I really feel the need to scribble, I can draw on a piece of paper and project the drawing. If the scale is not quite right, the zoom lets me show it off to full advantage and I don’t have to clean the white board afterwards. I have an internet connected computer in the podium as well. The video projector works great for showing MyHVACLab on the screen. When we discuss the questions at the end of the units, I project the e-book from MyHVACLab. Then I can show relevant information from the book as we review the unit and the students can follow along in their textbooks. I use the mouse to point out any particular coverage in the book I want to highlight. Of course the video projector also works for showing powerpoint presentations and video clips, but I have not shown any videos yet because I am too busy showing all the cool HVAC/R parts. I have a large collection all around my podium of things I have confiscated from the lab, including a few unit panels. If someone asks a question about a part I don’t have I am likely to find one by the next class. I got the idea I wanted to show the phase shifts caused by inductive reactance and capacitive reactance. The electronics department loaned me a digital dual trace oscilloscope that is small enugh to fit on the Elmo. I am going to build a circuit to show phase shift on the oscilloscope. I know lots of text books have drawings of this, but I don’t think many students pay a lot of attention to them. I am hoping when they see the shift occur right in front of them on the big screen in real time the information will sink in. At the very least, I know that I will have a good time playing with my new toys. I hope my students will see how cool this all is and want to play too.   

A Few Quick Service Tips

Technicians often feel pressure to work quickly. Many technicians have quotas- either the number of calls per day or revenue dollars per day. Even without an explicit quota, everyone works on a quota. You have to make money for your company or they cannot afford to employ you. If you are working for yourself, you have to make money to pay your bills. It can be difficult to put this out of our mind when we are working. There are some tricks you can use to maximize your productivity that are helpful, and there are some shortcuts that can get you in trouble. I believe that you save time overall by not skipping steps, but you can arrange your work flow to avoid wasted time. First, take the time to talk to the customer to find out what the complaint is and ask questions. Often, symptoms that the customer has noticed may give you some clues. Next, I always want to see the thermostat to verify that it is set correctly and calling for the system to operate. There are a significant number of customers that do not know how to operate their systems, especially with today’s programmable touchscreen digital thermostats. If the indoor blower is not running, set the fan switch to “On” to see if it comes on. If it does you know that the indoor unit has power, the transformer is providing control voltage, and of course that the fan and its control are working. If the fan does not come on, you have a good idea of where to start checking. Always do the easy stuff first. This is not just being lazy, it is being time efficient. It is never wrong to check the air filter; that should be done on each call anyway. If the filter is blocked you are wasting your time trying to adjust the charge. More often than not, the problem is a relatively simple issue. While you are changing the filter, take a look at the vent if the system is a gas or oil furnace. I have found vents rusted through while under a house checking a stopped drain in the summer. If you are the last HVAC/R technician at someone’s house, you have a responsibility for the safety of the system. For more ideas on efficient troubleshooting, check out Unit 86 Troubleshootng in Fundamentals of HVAC/R.

New R22 Units Coming!

The drama over the R-22 phasedown has been something of a soap opera. Just when you had adjusted to the fact that they killed off your favorite character, voila, they are raised from the dead! Manufacture of new equipment charged with R-22 stopped January 1, 2010. However, Carrier, Goodman, Lennox, Nordyne and Rheem are reported to be planning the production of dry R-22 condensing units for the replacement market.  How is this legal? Well, these are for replacement, not new installation. And,. they are not charged with R-22 - at least not by the manufacturer. A dry unit is one that is evacuated and charged with dry nitrogen, not refrigerant. The units can be used to replace existing R-22 units and then charged in the field. The replacement installer needs to purge the nitrogen charge, evacuate the entire system instead of just the lines and coil, and then charge the system with R-22 according to factory recommendations. Alternatively, environmentally conscious contractors could opt for a non-ozone depleting R-22 replacement. Check out Fundamentals of HVAC/R for more specifics on how to properly install an air conditioning system.

These dry R-22 units would give customers an option other than replacing their entire system with a new high priced 410A system. In today's economy customers often simply cannot afford to purchase a complete R410A system. They are left with a few bad options. Do without, or put money into repairing an aging, inefficient piece of equipment that really should be replaced. 

There are many questions to be answered, such as efficiency certification and avoiding potential legal landmines with the EPA. In some people’s minds it is not a good idea because they don’t believe today’s technicians properly evacuate the lines and coil on current systems. If these same folks charge an entire system without evacuating it, the head pressure would be so high that the system would likely not run long, if at all. This might be a blessing in disguise. If every unit they put in refuses to work, at some point even the most obstinate slacker would have to suspect that they are not doing it right. Success will depend more than ever on using skilled technicians that have the proper training. For more specifics, read the article on the Heating Air Conditioning and Refrigeration News website. R-22 has remained readily av available and the price has not spiked as much as had been predicted. Both of those situations may change if several major manufacturers start selling new products that require R-22 refrigerant. There are several R-22 work a likes now, but you had better check with the manufacturer before charging a new product with one of them. The equipment UL rating and manufacturer's warranty could possibly be voided by using an alternate refrigerant. For older equipment whose warranty has already expired, that is not too much of an issue. But for new equipment that still has a warranty, losing the the warranty would be a problem. Right now getting their efficiency certified is an issue. Air conditioners cannot be sold until they are certified to meet the minimum SEER rating. AHRI removed all their R-22 listing, thinking we were done with new R-22 systems. Stay tuned - it is bound to be interesting! 

Count Your Blessings

Last year I posted a thanksgiving article citing reasons for folks in HVAC/R to be thankful, myself in particular. If you are teaching HVAC/R, I know that you are experiencing record record enrollment at a time when your financial resources are dwindling. Although your job is difficult, you do have a job. A very important one at that. Your classes are filled with good men and women who do not have a job and they are looking to you for help. Both the economic situation and my reasons for being thankful in the face of adversity remain the same, so I am reposting last year's comments. 

At thanksgiving we should all take time to reflect on our blessings. For me this has been a great year filled with an abundance of blessings for which I am truly thankful. Unfortunately, many of my students have had setbacks in their life the past couple of years. I suspect many of your students have as well. We are seeing a wave of students who are preparing for a second or third career because their previous career was abruptly terminated. The plant they worked for closed, the building contractor they worked for has no projects, or the company they worked for has gone out of business. These are good people whose life has been turned upside down. It would be easy for them to concentrate on the past and what they have lost rather than what lies ahead. Dwelling on past misfortunes can be harmful to your health, adversely affect your present and threaten your future. I believe that one of the most important things we can do for these students is to keep them focused on their future. I have seen economic downturns and displaced workers before and I know the end game. These folks will merge their current skills, knowledge and experience with the knowledge and skills they will learn in their HVAC/R program to quickly become leaders in their new field. HVAC/R needs them.

Here is a list of a few things today’s air conditioning students can be thankful for.

• The need for heating, cooling, and refrigeration systems is only going to increase.
• They are starting a new career in a field that desperately needs skilled workers.
• There are still openings for skilled air conditioning technicians even during this economic downturn.
• Installation and repair of HVAC/R systems cannot be outsourced to foreign country.
• The wages earned will remain competitive because the work cannot be done by unskilled workers.
• They will enter the field with training for new refrigerants at a time when this knowledge is crucial.
• They will enter the field with training for new high efficiency systems at a crucial time as well.
• They are entering a field that is consciously increasing the level of professionalism and certification.
• They have experienced HVAC/R educators to help them make this career change.

I wish for all of you an abundance of blessings for the coming year.