Cash for Kash

One of the benefits of networking with other professionals is adopting strategies that have worked for other people. I recently attended a Building Automation Workshop where I met Keith Otten, a young HVACR instructor from Southwestern Illinois College. He explained that employment is essentially an exchange of resources. You receive cash for the kash you bring to the job. The more kash you bring, the more cash you can receive. The kash that you provide is knowledge, attitude, skills, and habits. I really like this mnemonic because it highlights the fact that employment is an exchange of resources. If you come to the deal with nothing much to offer, you can’t really expect very much in return. So the next obvious question, is how do you go about building your kash reserves?

Knowledge

Traditional and proven ways of acquiring knowledge include going to school, reading, and field experience. Today you would have to add networking through social media as a source of knowledge. I believe that the most important aspect of the knowledge component is recognizing how critical it is to continue the search. One advantage of the traditional route is that you can document your attainment. It is far more difficult to document that you watched 1000 great YouTube videos. Further, most schools and text books have some type of review process, so the knowledge you receive is much more apt to be helpful.

Attitude

Attitude is often part of a person’s personality. A positive, can-do attitude can often come through in interviews. So can a negative one. One of the best pieces of advice I have ever heard relating to attitude had to do with handling adversity. While it is true that you cannot control everything that happens in your life, it is also true that you CAN control how you react to the things that happen. By working to improve yourself and your situation, whatever that might be, you provide the framework for your own success.

Skills

Like knowledge, you can acquire skills by going to school. Unlike knowledge, skills require practice. You can gain knowledge about brazing by reading a book, but you cannot acquire the skill of brazing that way – you have to practice. You won't really get any better at brazing, no matter how many times you watch that YouTube video if you don't do some real world brazing. In school, labs provide that practice. In the field, job experience provides the practice that technicians need to become and stay proficient. Either way - to build skills you must actually do the work.

Habits

There is a famous quote by Aristotle “Excellence is an art won by training and habituation. We do not act rightly because we have virtue or excellence, but we rather have those because we have acted rightly. We are what we repeatedly do. Excellence, then, is not an act but a habit.” You become a skilled craftsman by practicing good work rather than bad. Acquiring knowledge, nurturing a successful attitude, and developing skills are all habits. By practicing these habits, you can build your kash reserves and start collecting more cash.

Calculating Wattage with Three Phase Devices

Have you ever wondered why the wattage of a three phase device is calculated using the formula: volts x amps x 1.73? I have. I am going to try to explain this without using too many mind bending formulas. First, there is the matter of not being able to read the total line current at one time. There are essentially three circuits in a three phase device – from L1 to L2, from L2 to L3, and from L1 to L3. Each leg carries only two of the three circuits, so measuring amps on any one leg checks the current of only two of the three circuits. The 1.73 factor is added to account for the effect of the current in the circuit that is not being measured. But why 1.73? 1.73 is actually an approximation of the square root of 3. We arrive at this factor by using trigonometry to calculate the combined effect of all the phases. Trigonometry is needed because the three phases are out of phase with each other, so simple addition and subtraction won’t work. The effect of the phases is described by a mathematical concept called a vector. A vector has both a direction and strength. An easy way to understand vectors is to imagine a wagon with a rope pulling it. With one rope, the wagon will go at the same speed and direction as the person pulling the rope. Tie a second rope to the wagon and have two people pulling in different directions, and now the wagon will travel a path somewhere between the two people. Now have one person pull faster than the other, and the wagon will travel a little more in that direction. Adding different AC voltages and currents is done with vectors because vectors can account for differences in strength and direction. Vectors involve angles and one of the best ways to calculate the effect of angles is with trigonometry, which simply means the study of triangles; specifically, right triangles. If you draw a line right down the middle of the 120° angle formed by two phases of a wye wound three phase device, you form two right triangles with 60° angles at their tips (120°/2). The remaining angle in each triangle is 30° because all the angles must add up to 180° (90°+60°+30°). The length of the line next to the 30° angle is found using the Trig function cosine of 30°, which happens to be the square root of 3 divided by 2. Since we have two of these triangles, the total difference simply the square root of three, which we approximate as 1.73.

Wattage of a three phase load is then calculated as watts = volts x amps x 1.73. Some refinements are necessary for accuracy. If the voltage and current are not identical in all three phases, you must average the volts and amps of the three phases, so the formula becomes watts  = average volts x average amps x 1.73. If you are checking an inductive load, such as a motor, you also need to include the power factor to compensate for the fact that the voltage and current in an inductive device are out of phase with each other. The formula becomes watts = average volts x average amps x 1.73 x power factor.

HCFC 22 Availability in 2013

This year, 2013, may be the last year of good availability of R-22. It almost certainly will be the last year of “inexpensive” R-22. In fact, we have probably already passed the “inexpensive” threshold. I would like to review the available quantities of R-22 to show a little perspective. The base year that is used in determining the percentages of allowable R-22 production in 1999 when 300 million pounds of R-22 was manufactured or imported in the US. That was cut to 100 million pounds by 2011. However, the reduction also coincided with the elimination of R-22 in the manufacture of new equipment beginning in 2010. Truthfully, we did not feel much of a squeeze because the primary purchasers of the refrigerant were no longer buying it. We even had a bit of a glut for a while, actually driving prices down. Then came the panic of January 2012 when all R-22 production ceased and prices jumped significantly almost overnight. This happened because the EPA had not finalized the rule allowing producers to manufacture and/or import HCFCs in the years 2012 – 2014. Basically, manufacturers did not want to risk receiving a big fine for exceeding the limits in a rule that had yet to be published, so they stopped making R-22. To get the R-22 flowing again, the EPA sent producers a letter stating that the EPA would not bring action against them so long as they did not make more than 55% as much in 2012 as they were allowed to make in 2011. So the amount of R-22 was cut to 55 million pounds for 2012. In fact, that rule has still not been finalized. Instead, the EPA has sent another letter to producers effectively limiting the 2013 allocation to 39 million pounds. Some wholesalers are now concerned about the availability of R-22. It is conceivable that some vendors may run out without being able to replenish their supply. The law of supply and demand is kicking in, driving the prices higher. In fact, now R-22 is now generally higher than the many R-22 replacement refrigerants. I still recommend using R-22 in systems designed for R22. However, you might want to start learning about the different replacement refrigerants available in your area as it looks like R-22 will soon be difficult to find, expensive, or both. One caveat: STAY AWAY FROM FLAMMABLE DROP-IN REFRIGERANTS SOLD OVER THE INTERNET! Putting a flammable gas in a system not intended for flammable gasses is extremely dangerous!
To read more about the availability of R-22 in 2013 read the ACHR News article.

Acetylene Cylinder Safety

I am writing on this subject because I saw a report on CNN discussing an explosion in the back of a car set off by energizing the electric trunk latch. It blew off the trunk and mangled the rear end of the car. Fortunately, nobody was hurt, but the possibility of a lethal accident was certainly there. The fireman that is interviewed mentions that there was an acetylene cylinder in the back of the car which leaked, and the trunk latch set it off. The acetylene should not have been there at all. Acetylene cylinders contain liquid acetone that is stabilized in a porous, cement like material. The acetone is there to dissolve the acetylene gas stored in the cylinder. Acetylene gas is unstable above 15 psig, but must be stored at a much higher pressure to store enough for practical use. Dissolving it in the acetone allows the higher pressure without creating a bomb. The cylinder regulator reduces the acetylene pressure to less than 15 psig. The actual pressure depends on the regulator setting. Note that you should NEVER adjust an acetylene regulator to a pressure above 15 psig.

Since acetylene cylinders contain liquid acetone, they should NEVER be laid on their side. They should ALWAYS be transported in the vertical position, securely fastened to the vehicle. Laying an acetylene cylinder on its side can result in the liquid acetone leaking out into the valve and regulator – setting up a very hazardous situation. You also should not have cylinders in the back seat behind you. Not just for the explosion hazard, but also because of the shifting weight in case of an accident. Any heavy objects behind you will crush you in an accident. My wife’s cousin was killed many years ago transporting cylinders in the back of his car. They crushed him in an accident that would otherwise probably not have killed him. That is why working trucks have a metal cage between the driver and the stuff in the back – to save your life in an accident. Basically, what this all means is that THERE IS NO SAFE WAY to carry an acetylene cylinder in your Prius! If you are going to transport torches or cylinders, you need a properly outfitted truck – not your family sedan.

Winter Airflow

Technicians often hear how critical airflow is in the cooling season, but we sometimes forget that it is just as important in heating as well. Just as poor airflow can be a major source of problems in the cooling season, poor airflow in the heating season can cause inefficient operation, high utility cost, and system failures.

Gas and Oil Furnaces
Gas and oil furnaces will operate with a higher than normal temperature rise if the airflow through the furnace is inadequate. While the air leaving the registers will be toasty, this can actually result in less heat being delivered into the house. The limit switch on a furnace with inadequate airflow will typically cycle the burners on and off  - reducing the amount of heat being produced. The cycling causes poorer operating efficiency, increasing the cost of operating the furnace.

Electric Strips
With electric furnaces and strip heaters, poor airflow will eventually result in open fusible links, bad thermal limits, and open heat strips. Like the gas and oil furnaces, the thermal limits may cycle the strips on and off, reducing the amount of heat.

Heat Pumps
Heat pumps with poor indoor airflow will operate at excessive head pressures because the indoor coil is the condenser in the heating cycle. This reduces system capacity by increasing the compression ratio while the compressor is operating.  Eventually, the compressor will cut off on the high pressure switch. Usually, the high pressure switch will need to be manually reset, meaning no compressor heat until the service tech arrives. Systems without a high pressure switch will shut off on the compressor internal overload. Once that happens, the compressor may not come back on for a couple of hours. Either way, the compressor is taking a beating and the system is using more electricity to produce less heat.

So if you run into furnaces that are cycling on the limit, electric strips with open fusible links, or heat pumps with tripped high pressure switches – check out the system airflow. Remember those are all symptoms – not the root cause. Fix the cause of the problem – poor airflow.

Short Refrigerant Cylnders

Recently Mr. Simmons, one of our air conditioning instructors at Athens Technical College, noted that a new cylinder of refrigerant felt light compared to the others. A quick check with a scale confirmed his suspicion – the “30 lb” cylinder only weighed 22 lbs including the cylinder and outer cardboard packaging. However, it had never been used. The plastic seal was still intact.  It made me wonder if there were other cylinders that we have used and did not catch. We checked a few others, and it seemed that one cylinder was the only “short” cylinder. Obviously, a cylinder that holds 30 lbs of refrigerant should weigh more than 30 lbs. How much more should it weigh? Generally, the whole package including the box should weigh around 36 lbs. The empty DOT 39 cylinder weighs around 5 lbs and the box weighs approximately 1 lb. I don’t know if our experience is unique, or if it is common for refrigerant cylinders to be short, but I will most certainly be checking from now on. I recommend that you weigh your cylinders before opening the seal to make sure you are getting what you are paying for. A great deal on refrigerant is not a great deal if they don’t actually give you the full amount you are paying for. In our case, I called the company that we purchased the refrigerant from and they quickly replaced the cylinder with a full one. I weighed it to make sure.

Where Are You Headed?

Where are you headed? With the new year, many people ponder what their new year’s resolution should be. One suggestion would be to determine a goal, lay out a plan to reach that goal, and then start working towards it. I read that the legendary quarterback Archie Manning encouraged his sons to write down their goals. Peyton Manning writes his on notecards. I don’t know what was on the cards, but having specific goals and working towards them seems to have worked pretty well for the Mannings. Sometimes students get discouraged by the length of many HVACR programs. The simple truth is nobody can make you a successful technician, or anything else for that matter, in a couple of weeks. The only person that can really make you successful is you. So let me ask you, what are you planning for the next couple of years? Time will pass whether or not you work towards a goal. So where will you be in two years – graduating from a program of study and embarking on a new career, or will you be exactly where you are today?