New Age Digital Tools

I am a big fan of tools that make my work easier. Tools that improve your efficiency not only make your life easier, they make sense economically. The most expensive part of a service call is the service tech. Your time is more valuable that most of the parts you put on. I don’t mean what you receive in your paycheck, but what you cost the company. You cost more than the parts. Saving your time saves the company’s money. I know one contractor that understands this. He does not want techs trying to work with worn out or inappropriate tools. He understands that the time they spend trying to work with the wrong tool costs him money. So his company supplies all the tools for his techs and even replaces them when they are worn or lost. Today’s technicians can benefit from a wide array of technology driven new-age HVAC/R tools. Digital everything! Now technicians can use digital tools to measure pressure, temperature, superheat, subcooling, vacuum, relative humidity, dew point, wet bulb temperature, weight, air pressure, barometric pressure,  air speed, CO, CO2,  and combustion efficiency just to name a few. I did not even include all the electrical measurements available with today’s multi-meters. Indeed, there are many tools available that measure several system characteristics. I must admit that when I look through a catalog of a company that carries several lines of these tools I feel like a kid again looking through the toy section of Sears Christmas catalogue checking off every shiny toy. I want this, I want this, …It would be easy to spend $10,000 on inexpensive digital tools. But since that exceeds the weekly take home pay of your typical service tech, we have to make some choices. The parameters I use in deciding are

1. Does it do something that I need to do often?
2. Is it really superior and faster than what I do now, or is it just digital?
3. Can it do something that I can’t do now?

So by all means, arm yourself with an armada of new-age digital tools, but take time to assess what the new tool will do for you before you invest your paycheck. Otherwise, you could end up with a large collection of expensive digital toys.

If you would like to learn more about HVAC/R, check out Fundamentals of HVAC/R.

Poly Who?

The emergence of HFC refrigerants has added a new set of confusing chemical names and properties with which the HVAC/R technicians must be familiar. One of the more confusing developments in the refrigeration industry in recent years has been the plethora of impossibly difficult to pronounce polys used for refrigerant oil with the new HFC refrigerants. There are several synthetic lubricants with multisyllabic names that begin with poly: polyalkylene glycol, polyol ester, and polyvinylether. Polyol ester is actually “short” for neopentyl polyol ester. To make discussion of these chemicals possible, they are generally referred to by three letter abbreviations:  PAG, POE, and PVE. Polyalkylene glycol(PAG) is widely used in car air conditioning systems, but is generally not used in hermetic and semi-hermetic systems because of its lower electrical resistance. Currently, polyol ester, POE, is the primary lubricant in hermetic and semi-hermetic systems using HFC refrigerants. POE has been used for years as a lubricant in jet engines. One advantage POE has in refrigeration is that it is compatible with a wide range of refrigerants including CFCs, HCFCs, and HFCs.  Another important characteristic is relatively high electrical resistance, making POE superior to PAG for hermetic and semi-hermetic systems. A major disadvantage is that POE is very hygroscopic; it readily absorbs water. Water is never welcome in a refrigeration system (unless the system is a lithium bromide chiller). However, water in a system with POE is a particularly bad set of circumstances. To understand why this is such a problem you need to understand how POE is made. POE is made by a reaction with acid and alcohol which yields water and POE. Like many chemical reactions, it can be reversed. Add water and heat, and POE reverts to acid and alcohol. The hydrolysis of POE creates goo that clogs metering devices, filters, screens, and oil holes. Filter driers are absolutely essential for all systems with POE because of this added water hazard. Even deep evacuation will not adequately dehydrate a POE system if there is already any water in the POE. Some links to sites that discuss these lubricants are PAG, POE, and PVE.    

Hero Convoy

I was in Nashville this past weekend nervously watching the weather reports and trying to determine exactly when I needed to start my six hour trip back home in order to beat the impending winter storm. There was heavy traffic all the way, all manner of cars, trucks, and commercial vehicles. Maybe they were also trying to beat the storm south. Mixed in with the regular traffic were several convoys of cherry pickers from several states. There was a convoy of 30 bucket trucks from a power company in Michigan. I also remember another convoy of trucks from Kentucky. A lot of my pent up concern and worry melted away when I saw these convoys of heroes because I knew good people were positioning themselves to help. While the rest of us were trying to run away from the storm, they were running towards it. What does a hero look like? If you are cold and out of power, the guy in the bucket truck is way better than superman. A hero is someone who leaves the comfort of home and travels to places where the weather is guaranteed to be wretched so they can hang from a pole and play with wires that could have thousands of volts traveling through them. Heroes aren’t super human beings that accomplish awesome tasks easily without effort or suffering. No, heroes are everyday folk who put forth the effort and bear the suffering for the sake of the rest of us. Thank God for the heroes in the bucket trucks!  

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.