The Christmas Gift

A few years ago Mike would have been annoyed to be asked to work on Christmas day. After more than a year without a steady job, he is pleased to work this Christmas. Mike worked hauling sand and gravel for construction and there simply has not been much demand for those services. Last Christmas he was concerned about how he would provide for his family. This Christmas he is working at a local hospital doing systems maintenance, and he is happy to do it. Not only does he receive a steady paycheck, but he also receives decent job benefits, including health insurance. In short, he can provide for his family. Further, he is performing a valuable service that he takes pride in. Nobody is giving him anything, he has earned it. His employers are pleased to have a skilled worker at a time when truly skilled workers are hard to come by. There are a lot of people wanting jobs, but not so many offering the skills needed for an HVACR technician. The people in the hospital have a place to go to heal thanks to the workers like Mike who work through the holidays insuring everything in the hospital keeps running. So what is the difference between last Christmas when he did not know how he would support his family and this Christmas when his services are needed? Education. Mike enrolled in Air Conditioning Technology at Athens Technical College. He could not have afforded the cost of school entirely on his own, even though our costs are quite low compared to other colleges. He received help from government programs promoting technical education. In essence, we the people made an investment in Mike. So what did we receive? The government will get their money back in one to two years of taxes. Afterwards, the taxes on his income can be used for years to come. Mike’s family will not need any government support because he is supporting his family. The hospital receives a skilled and loyal employee to help provide a place for the community to heal. Mike practices a skilled trade in a profession he truly enjoys. We received a great deal. Merry Christmas Mike.

EPA Approves Flammable Hydrocarbon Refrigerant Use

On December 14, EPA issued a final ruling approving 3 flammable hydrocarbon refrigerants for use in small domestic and commercial refrigeration appliances. The three hydrocarbon refrigerants approved as acceptable substitutes are propane, isobutane, and R-441A. Hydrocarbons will now be allowed in domestic household refrigerators, freezers and window air-conditioners in the USA. Isobutane R-600a and a proprietary blend R-441A. are approved for use in household refrigerators, freezers, and combination refrigerators and freezers. R-441A is a patented blend of ethane, propane, butane and isobutene. Both its ozone depletion potential and its global warming potential are 0. It is also considerably more energy efficient than R-134a. Flammable refrigerants have been used for many years in small refrigeration appliances in other countries, including China. One of the most likely immediate effects of this ruling is to allow importation of refrigeration appliances charged with hydrocarbon refrigerant. Propane is approved for use in stand-alone retail food refrigerators and freezers.  There are restrictions on the use of these refrigerants due to their high flammability.

1. They me only be used in new equipment specifically designed for their use.

2. the appliances must meet the UL Standard 250 for household refrigeration  or UL Standard 471 for retail food refrigeration.

3. The quantity of refrigerant in a refrigerator or freezer shall not exceed 57 grams (2.0 ounces) in the household refrigeration end-use or 150 grams or (5.3 ounces) in the retail food refrigeration end-use.

4. The appliances must be marked with designated flammability warnings.

5. The piping and service ports must be painted red with a specific red color : pantone 185.

6. The service aperture must differ from regular non-flammable refrigerant service apertures.

7. These refrigerants may not be sold for use as a refrigerant in containers designed to contain less than 5 pounds (2.3 kg) of refrigerant.

To read more check out one of the following links:
Draft of Final Ruling
Supermarket News Article
ACR News Article

Cold Weather Heat Pump Charging

Checking the refrigerant charge of a heat pump in cold weather can be confusing for many technicians, at least partly due to the many different methods recommended by different manufacturers. Although there are many methods, most are described as heating performance charts or heating cycle check charts. A check chart is just that, a chart for CHECKING the charge during the heating cycle. It is not intended to be used for actually ADDING refrigerant. Why? Lower outdoor temperatures cause a lower evaporator temperature and pressure. Lowering the evaporator pressure increases the compression ratio, so the compressor capacity is reduced. Less refrigerant is being circulated in the refrigerant system because of the diminished compressor capacity at low outside ambient temperatures. The refrigerant that is not being circulated must sit somewhere, usually in the accumulator. For this reason, a charge which is adequate to maintain correct pressures and temperatures at 25°F may not be adequate at 35°F. How? Suppose that the unit was undercharged according to the check chart. If you add just enough refrigerant to bring it up to the required pressures, you have only added enough refrigerant for correct operation at that one condition. When the outside temperature rises, the unit will be capable of pumping more refrigerant. However, since you didn't add any extra refrigerant, there won't be any more to pump. The system will be undercharged. Just adding a little extra is not a great ida either because you really have no way to determine how much extra to add. This is why manufacturers say that the check chart cannot be used to CHARGE the system, only to check its operation. If the system is undercharged, the recommendation from many manufacturers is to recover the refrigerant in the unit and weigh in a total system charge according to the manufacturer's instructions. 

Thanksgiving 2011

Once again, Thanksgiving is here and I have so much to be thankful for its hard to know where to start. My family is doing well, my children are achieving and prospering, and my HVACR program has so many students that we have had to work really hard to meet their needs. All the Air Conditioning instructors at Athens Tech have really stepped up their game. Dennis Payton, Coleman Simmons, Gary Manley, Jack Parsons, Gene Smith, Bill Ely, and Kenneth Harris have done a stellar job this semester. I know that our students are fortunate to have the dedicated and talented instructors that I am fortunate to work with. We are coming to the end of our first semester since our system switched from quarters to semesters, and the transition has been smoother than expected.

I know that there are still far too many people without work and that the hard times have boosted our enrollment as people look to invest in their future. Our job as teachers is to insure that they have made a wise investment. We are preparing our students to answer the call when opportunity knocks. How many stories have you heard about someone being successful because they were in the right place at the right time? There is another part of their success that often goes unmentioned: they were prepared to answer when opportunity knocked. That is what students all across America are doing today – preparing for opportunities to come. Schools are bursting at the seams. We are planting the seeds of tomorrow’s success. I truly believe that a better educated, better trained pool of workers will propel our country into a time of prosperity in the coming years. Times will get better, opportunity will knock, and our students will be thankful that they were prepared to answer the call.

80% Furnace versus 90% Furnace

This week I would like to follow up on the 80% versus 90% debate. The primary argument for installing an 80% furnace is the lower cost of the equipment. However, a colleague of mine suggested that there is really not much difference in the installed cost because of the difference in the cost of the vent pipe. Standard B-vent is far more expensive than the PVC that is used in 90% furnaces. If the furnace is in a crawl space or basement, the 80% furnace must be vented through a chase or closet while the 90% PVC vent can usually be run sideways out through the wall. This also saves on labor. His argument is that the extra cost associated with installing a Category I furnace vent eats up the difference in cost between an 80% furnace and a 90% furnace. 

For a changeout, the math will favor an 80% furnace because there is already an existing vent. However, check to see if the vent is adequate. You may need to make improvements to the existing vent for the furnace to operate safely. Often, a fan assisted replacement furnace will use a smaller vent than the older natural draft furnace it is replacing. It is possible for the old vent system to be too big, causing condensation inside the vent which leads to rapid vent corrosion. Many older natural draft furnaces are vented into masonry chimneys, a practice that is usually discouraged when applying fan assisted furnaces. Several manufacturers require a metal flue liner for the masonry chimney, eating up most of the cost savings. Another common practice in older furnaces is the use of single wall vent connector. You really don’t want to connect a new fan assisted furnace in a cold location to a single wall vent connector, especially not an old one. I have seen single wall vent connectors rust through and fall on the ground in less than a year after installation of a new fan assisted Category I furnace. Again, replacing the old vent connector eats up some of your savings.  

It is true that there is still quite a cost difference between an 80% single stage furnace with a PSC blower and standard controls versus a 90% two stage furnace with an ECM motor and communicating controls, but the cost difference has more to do with the improved blower and controls. For a true cost comparison, both furnaces should have similar blowers, staging, and control systems.

Appliance Energy Efficiency Standards

The Federal Department of Energy, DOE, has issued a direct final ruling making on furnace and air conditioner efficiency. The regional efficiency standards ruling went into effect October 25. The country is broken into three regions: North, Southeast, and Southwest regions. A map can be seen at MAP. Read more about the ruling at RULING.

In a nutshell: in the Northern region furnace efficiency will increase while heat pump and air conditioning efficiency will remain the same; in the Southeastern and Southwestern regions furnace efficiency will remain the same while heat pump and air conditioning efficiency will increase.

The table below listing the changes comes directly from the final ruling.

Table I.1 Amended Energy Conservation Standards for Furnace, Central Air Conditioner, and Heat Pump Energy Efficiency

Residential Furnaces*
Product Class	National Standards		Northern Region** Standards
Non-weatherized gas	AFUE = 80%		AFUE = 90%
Mobile home gas	AFUE = 80%		AFUE = 90%
Non-weatherized oil-fired	AFUE = 83%		AFUE = 83%
Weatherized gas	AFUE = 81%		AFUE = 81%
Mobile home oil-fired‡‡	AFUE = 75%		AFUE = 75%
Weatherized oil-fired‡‡	AFUE = 78%		AFUE = 78%
Electric‡‡	AFUE = 78%		AFUE = 78%
Central Air Conditioners and Heat Pumps†
Product Class	National Standards	Southeastern Region†† Standards		Southwestern Region‡ Standards
Split-system air conditioners	SEER = 13	SEER = 14		SEER = 14 EER = 12.2 (for units with a rated cooling capacity less than 45,000 Btu/h) EER = 11.7 (for units with a rated cooling capacity equal to or greater than 45,000 Btu/h)
Split-system heat pumps	SEER = 14 HSPF = 8.2	SEER = 14 HSPF = 8.2		SEER = 14 HSPF = 8.2
Single-package air conditioners‡‡	SEER = 14	SEER = 14		SEER = 14 EER = 11.0
Single-package heat pumps	SEER = 14 HSPF = 8.0	SEER = 14 HSPF = 8.0		SEER = 14 HSPF = 8.0
Small-duct, high-velocity systems	SEER = 13 HSPF = 7.7	SEER = 13 HSPF = 7.7		SEER = 13 HSPF = 7.7
Space-constrained products – air conditioners‡‡	SEER = 12	SEER = 12		SEER = 12
Space-constrained products – heat pumps‡‡	SEER = 12 HSPF = 7.4	SEER = 12 HSPF = 7.4		SEER = 12 HSPF = 7.4

The increased standards will be phased in over a period of years. Compliance with the standards in the direct final rule will be required on May 1, 2013 for non-weatherized furnaces and on January 1, 2015 for weatherized furnaces and central air conditioners and heat pumps. Industry reaction has been split. AHRI helped to develop the standards and supports them. They want to avoid the confusion and cost that was associated with the 13 SEER efficiency change that gave the industry very little time to prepare. AHRI also points to the Canadian experience when they mandated 90% . Their sister organization, HRAI, has stated that there were very few problems with Canada’s implementation of 90% standards. Read the AHRI position at LETTER. 

ACCA opposes the standards, especially the 90% furnace mandate, concerned that the extra cost will drive customers to illegal contractors, who feel no compulsion to follow the rules and will cheerfully install equipment that legitimate contractors are not allowed to offer. read ACCA position at ACCA. 

HARDI also opposes the regional standards, citing the difficulty this will make for distributors who service two or more regions. Read HARDI position at HARDI. ACCA and HARDI also cite that there is currently no enforcement mechanism – no DOE police. Again, the problem is that contractors who don’t abide by the ruling achieve a competitive advantage over contractors who do. Regardless of how you feel about the ruling, this is now the law, and all of us in the HVACR industry should prepare ourselves. As far as the DOE police – be careful what you wish for! 

Southface

The Georgia State Consortium of Air Conditioning Instructors met on October 25 at Southface in Atlanta. Southface is a non-profit agency devoted to energy efficiency and sustainability in buildings and communities. In keeping with their ideals for sustainability, Southface does not allow bottled water, box lunches, or  syrofoam cups in their facilities. I must admit, I was a little put out with all the rules. “Who do these people think they are?” But then I realized, they are actually practicing what they preach. They know who they are. A sponsor, Technical Training Aids, graciously provided our lunch wthin the confines of all the rules and it was great. We gathered there to hear about what Southface could offer and tour their facilities. They provided an overview of the new residential energy efficiency code and its application in Georgia. All new residential construction in Georgia is required to pass a blower door test and all new duct systems must pass a duct blaster test for tightness. Those two requirements are the big ones for HVACR contractors. Further, the people performing the test must be state certified to perform it. They get certified by taking a relatively short course that lasts less than a week and then passing a performance test. So at least in Georgia, installing tight duct systems is no longer an “add on” for the better homes, but a requirement. Although there will certainly be many contractors that will regard all this as a pain, at least one in Athens sees it as an opportunity. Anytime he sells a high efficiency changeout, he quotes a duct seal and wrap upgrade. A seal and wrap consists of removing the old duct insulation, sealing the duct, re-installing the old insulation, and insulating over the old insulation. The duct blaster is used to measure the duct leakage before and after the job to document the improvement. So even if you don’t work in Georgia, you might consider promoting duct sealing and insulation. If your competitors don’t do it, that is a way to differentiate yourself from them. Most homeowners can easily understand that leaky ducts cost them money. For many systems, sealing and insulating the ducts will improve system efficiency even more than installing a new high SEER system.

Making Connections

Most curriculums, courses, and books are organized in a manner that resembles house construction. You lay the foundation and then add to that foundation as the material gets progressively more complex. The idea is to present the information in an orderly manner so that complex concepts can be understood. I believe that teachers have been using this general scheme for centuries. I also believe teachers have been frustrated for centuries when they discover that the reason the students don’t understand a higher level concept is that they really don’t make the transition from one conceptual level to another. The problem is that learning is really not too much like stacking bricks, but more like wiring circuits. We have to make connections to learn. It is not enough to present material in an orderly and logical fashion, we must also make connections between different pieces of information. Every chance you get, you need to show how one piece of information connects to another. The more mental connections the students make, the more likely they are to remember the information. Students sometimes ask how a particular piece of information is relevant. I believe what they are trying to say is that they don’t have anything to tie the information to. Random, disconnected facts are quite difficult to remember, and are not normally particularly useful. I like the Bing commercials where people blurt out a series of largely unrelated facts that are essentially useless because there is no logical connection between them. To students, I am sure our lectures can sometimes sound like one of these commercials. I try to connect ideas together – showing how one part of a system affects the others, how pressure is related to temperature, how resistance is related to current – you get the picture. Relationships and connections between ideas are just as important as a carefully crafted sequence of information. This is not to suggest that building a foundation of information is wrong, I would just use the analogy of a framework instead. A framework can allow connections in more than one direction. Understanding a few fundamental physics concepts provides a framework for understanding both refrigeration and electricity. Taken by itself, physics can be pretty dry stuff until you realize that it describes the world around us. Once the students start making connections linking concepts together the whole process can go viral – they start finding their own connections and asking their own questions. This can be a bit scary because you no longer have total control of the flow of information or questions, but it produces an energized, lively class. More importantly, when the students start connecting concepts they are taking an active role in their learning and are far more likely to retain the information.

Electric Heater Resistance - A Moving Target

Most people know that inductive loads such as electric motors draw more current when they start. Did you know that this is also true of most electric strip heaters? The resistance of a conductor increases as its temperature increases. This is true of the nichrome wire used in electric heaters. The heater resistance is less when the heating coil is cold than after it heats up. The increase in resistance causes a decrease in current. In short: an electric heater draws a little more current when it starts than after it heats up. The difference for an electric strip heater is nothing like the huge surge that a motor has, but it is measurable. For incandescent light bulbs, the difference is huge because the temperature difference between hot and cold is much greater. An incandescent light is basically a heater that gets white hot and gives off light. Lights don’t work for Ohm’s Law experiments because their resistance hot is around 10 times as high as their resistance cold. Many years ago I tried having students do Ohm’s Law calculations with lights – it just does not work. The readings were so far off, that the results did not make sense.  I tried to put the difference down to measurement error, but the readings were always similar. Screw in cone heaters work better, but if you put enough current through them for them to get red hot, their resistance will increase and your readings will still be a little off. At least they are in the ballpark. It is something of a catch 22. To measure resistance an ohm meter puts a small amount of voltage across a resistance and measures the current, and then determines the resistance based on the amount of current that flows through the resistance. The problem is that the resistance changes when different amounts of current flow through the same device, based on the temperature change of the device.  Remember that the resistance is turning the electricity into heat, and the heat changes the resistance of the device. Fortunately, the relatively small difference we see in electric strip heaters does not create a substantial problem for us, but it does raise questions when trying to demonstrate Ohm’s Law. If you want to reduce the amount of error introduced by the temperature change, just work with lower voltages and current levels. Use a typical electric strip heater, but only put 50 volts through it. The current and voltage are still measureable and the results will be much closer to what Ohm’s Law predicts. I know there are probably many skeptics reading this, so I challenge you to prove it to yourself. Take a heater, a variable voltage source, a voltmeter, and an ammeter. Read the current draw of the heater at several voltages ranging from just enough voltage to get a current reading to the full voltage the heater can take. Then calculate the resistance using Ohm’s Law by dividing the measured current into the measured voltage. You should see that the resistance is higher at higher voltages because the heater is getting hotter. Have Fun! 

Combustion Air - Don't Forget It!

I am re-posting an article from October 2009 when I talked about combustion air because I believe failure to check the combustion air is a common error in performing gas furnace service.

The arrival of fall brings the start of gas and oil fired furnace seasonal checks. An easily overlooked problem with gas and oil furnaces is lack of combustion air. Although most technicians understand the necessity of adequate combustion air, it is easily overlooked if the technician views their job as servicing appliances rather than systems. Most school shops have no combustion air issues because they are typically great big leaky rooms. On the other hand, the newer homes your students are likely to see are typically very tight, requiring installers and service technicians to be conscious of the need for combustion air.  I believe we should stress the consequences of inadequate combustion air. Most students understand that air is required for combustion and that new air must constantly be brought in to replace the air that was just used in the combustion process. They should understand that the carbon and hydrogen in the fuel are combining with the oxygen to make carbon dioxide and water, the normal products of complete combustion.  You can then explain that if there is not enough oxygen, carbon monoxide and unburned carbon will start to form because there is not enough oxygen to complete the combustion process. As the combustion process continues in a room with inadequate combustion air, the pressure in the room becomes negative. This will reduce the effectiveness of the vent. In bad cases the combustion products can start to spill out of the vent. Now you have a scary situation: a combustion process producing carbon monoxide and combustion gasses spilling out into the room! I have heard of cases where smoke from fireplaces in newer homes comes rolling out into the room when the furnace comes on because the house simply does not have enough combustion air for both the fireplace and the furnace. Technicians should look for combustion air grills and vents when servicing furnaces. Typically there should be an opening or grille near the ceiling and another near the floor. If the grille opens directly to the outside the free area of the grille should be at least one square inch for every 4,000 Btuh of combined input rating. If the combustion air must travel through vertical ducts the ducts must also have a free area of at least one square inch for every 4,000 Btuh. If the air must travel through horizontal ducts, the grille and the ducts must be larger. They must have a free area of at least one square inch per 2,000 Btuh. Draft measurements and room pressurization measurements can tip off technicians to combustion air problems. Because a draft gauge measures the vent pressure relative to the room pressure, inadequate combustion air will cause the draft reading to decrease the longer the furnace operates. An absolute pressure reading of the room will show that the room pressure is decreasing as the furnace continues to operate without adequate combustion air. A quick test is to introduce more combustion air near the furnace by opening a window or door to the outside. If the draft increases when the window is opened and decreases again when it is closed, the room needs more combustion air. For more a more detailed discussion of combustion air check out Unit 37 Gas Fired Heating Systems, Unit 40 Gas Furnace Installation, Startup, Checkout and Operation, Unit 41 Troubleshooting Gas Furnaces, and Unit 44 Residential Oil Heating Installation in Fundamentalsof HVAC/R.  

Budget Stretching Ideas

Schools face a serious budget crunch these days created by expanding enrollment and shrinking resources. There are many small things that you can do to stretch your budget and still provide a reasonable level of training for your students. Refurbishing tools that have become shop worn rather than replacing them is one small possible savings. Tools that normally last for years in the field sometimes only last a few semesters in our lab due to the harsh treatment they sometimes receive as well as the constant use. The seals and depressors in hoses are one example. If you have refrigeration hoses that leak, often the leak is in the seal on the end. The seal in most hoses is a small rubber tube that slips into the end of a brass cup in the end of the hose. The core depressor is either held in place by the seal or screws down into it. Replacement seals and depressors are available for most brands of hoses. If the hoses you have are used for connecting to refrigerant cylinders, vacuum pumps, or recovery machines, there is really no reason to have the core depressor. Removing it will speed up all those operations by removing a restriction. A larger savings can come in the type of brazing rod you keep. While I prefer 15% silver, it is now over $100 a pound and we use several pounds a semester. I hate to have students braze any less because brazing is one of those skills that must be practiced. 0% copper-phos is just over $10 a pound and does the same job. No, not as easily, but I can buy a semester’s worth for less than one pound of the 15% silver. Another savings for many programs is to reduce the paper you hand out. I have always been fairly liberal with the handouts, believing that it is important to disseminate information. I still believe that, but I have modified the way I share information. I started by writing a book that had more of what I wanted in it. But there will always be new information you run across that you want to share. Increasingly, I do this electronically by sharing web addresses. Finaly, let the supply houses and contractors in your area know you need help. They can keep their eye out for opportunities to help you. This past year we have received several donations from contractors and supply houses of “stale” stock or equipment with issues. They receive a tax deduction and we receive equipment. A unit with an issue may be a problem for a contractor, but it is an opportunity for my students . We have received two new packaged heat pumps this past year that had leaks on the pilot tubes of the reversing valves. Students patched the leaks and the valves worked. Now we have two new packaged heat pumps.  

Picture Perfect

Several years ago when I was a student in one of my education classes at the University of Georgia, the instructor asked us what should have been a fairly simple question for a group of teachers: “How do you know when learning has taken place?” I don’t remember my response, but I do remember that the question really brought me up short because it was not asking how do you know when the student has mastered a particular knowledge or skill, but how do you know when they have learned something? Well it is a little late, but I received a great answer today: Learning has taken place when the student requests that their picture be taken with their project. We have a flaring project in which students make an assembly of 1/4”, 3/8”, 1/2”, and 5/8” copper all connected together by flare fittings. After it is done, it is tested for leaks with 100 psig of nitrogen and soap bubbles. After completing their project, one student wanted a picture. Then they requested I take a picture of them holding the project. The student’s broad smile gave me the answer to the question posed to me many years ago. Learning has taken place when the student can enjoy the pride of achievement with tangible proof of their accomplishment. In technical education we have a huge advantage of being able to actually produce. The students’ pride is not based on my judgment, it is based on holding something they made that they could not make yesterday. Some people consider trade skills and knowledge as inferior to pursuits that are purely academic. However, I feel that a strong case can be made that technical skills are actually a higher form of learning because the students must actually perform. Reality is the harshest judge of all – either it works or it doesn’t. Our students must not only understand the theory, they must also apply it and pass the performance test. So if I had to list a learning sequence today, it would be: you study, you struggle, you sweat, you smile! 

Brain Building

Your brain is an essential component for all forms of education. One obvious way to improve learning results is to improve students brain capacity. Some forms of teaching are better than others at building brain capacity. I have noticed that frequently, “smart” students actually work harder than “dumb” students. I believe that their study habits and the way they approach life in general not only builds their knowledge, it also builds their brain capacity. Just as hockey players skate and football players run to improve their ability to perform the fundamental movements of their sport, students should exercise their brains to improve their ability to learn. So what types of things build brain capacity? One proven way to build your brain is by learning to play a musical instrument. Playing an instrument uses both halves of your brain simultaneously, requiring better communication to be developed between the right and left hemispheres. A few years ago at my son’s band concert, I realized that the trumpet section was also three fourths of the schools award winning math counts team. Playing an instrument is both incredibly difficult and incredibly rewarding. Looking into this a little, I learned that Einstein played the violin. His brain was perhaps one of the most studied in history. He had grown an extra lump on the right side of his brain, a feature found in autopsies of other proficient violin players. Einstein had to expand his brain capacity to play the violin! Of course it is possible that playing music does not make you smart, but that smart people enjoy playing music. OK, so besides brain building there are some more obvious benefits. For one, you learn self-discipline. You simply cannot learn to play a musical instrument without the self-discipline that comes with practice. Then there is group disciple. The members of orchestras and bands must learn to work together as a group to perform music. The group objectives can only be met by subjugating all their individual egos. As a parent, there are a few other benefits. After half-time we hand out drinks to both bands. I am always impressed by how polite and truly thankful the band members are. They all say thank you and are gracious even if we have run out of cold drinks and are handing out warm water. When I look out over the gathering of the two bands I know I am seeing leaders in every imaginable field and I am positive about the future.   

Looking for a Day On

As we celebrate this Labor Day I am reminded of the many Americans who don’t want a day off, they are looking for a day on. Your job provides you with more than the financial means to support yourself. For most of us, we are identified by our profession. One of the first things people ask when meeting is “what do you do?” Having regular earned income also gives us a way to be more in control of our destiny. With a predictable source of income, you can manage towards improving your lot in life. I truly believe all our political leaders want to help. We would all like for everyone seeking employment to find it. There have been many attempts by government at all levels to pass legislation that would stimulate the economy and create jobs. The problem is that it is very difficult to create truly new jobs, particularly in new and emerging technologies. I believe we would have more success investing our time and money training people for jobs that already exist, particularly in fields where industry growth exceeds the available workforce. HVACR is one such industry. Jobs are available now for skilled HVACR technicians, even with the construction industry operating at historically low levels. Money spent in technical education prepares students for real jobs that we know exist, not jobs that we wished exist. Preparing people for a real job that pays real money makes them a contributing taxpayer. In short, the government gets the money back. Some HVACR students will be successful enough to start their own business. There are several in the Athens area who started as students at Athens Tech. One relatively small business with five employees can gross $500,000. That generates tax revenue of $75,000 at 15%. If those five employees are trained at Athens Tech, the cost of their training is less than one year’s tax revenue. Not all students will generate that kind of return, but even a student earning $12 an hour will likely pay back the cost of training in two years. For people who already have a job in HVACR, education makes them more productive. Increased productivity means a better bottom line for the government – more income to tax. It is not necessary to start new programs with new administrative costs; there are already programs and institutions in place with proven track records of training workers for skilled trades. All we have to do is support them.

Variable Speed Motors

Electronically commutated motors are widely described as variable speed motors. In truth, most blower motors used in air conditioning are variable speed, including shaded pole and PSC motors. Muliple tap shaded pole and PSC motors are designed specifically to vary their speed based on the tap that is powered. All induction motors vary their speed depending on the load. An increase in load will result in decreased motor speed. What makes ECM motors unique is their ability to vary their speed intelligently in response to the load. They are often used to vary motor speed to maintain constant airflow. To do this, the motors are programmed to match the performance of the blower on which they are mounted. When the airflow through the blower is restricted, the motor responds by speeding up enough to keep the blower CFM the same. In truth, a common PSC blower motor also speeds up when the air through the blower is restricted. However, it does not speed up enough to offset the loss of airflow caused by the restriction, so the airflow decreases. The PSC motor is just responding the way any induction motor does to a decreased load. On a blower with a PSC motor, an airflow restriction causes a decrease in airflow and in motor amp draw because it is not under as much load. A blower with a constant CFM electronically commutated motor will still move the same amount of air by increasing the speed enough to overcome the restriction. Because the motor is doing more work, the amp draw will increase. This is why good duct design and clean filters are important to ECM equipment. The blower motor on a new system with an ECM motor may actually draw a higher amp draw than the old PSC blower it replaced if it is connected to a restrictive duct system.  The popular X13 motors by Genteq are constant torque ECM motors. They vary their speed to maintain a steady torque output. When the blower airflow is restricted, the X13 ramps up its speed to maintain the same torque output. This will usually not be enough to completely overcome the restriction, but it will not be producing less torque when the system needs more torque, as is the case with a PC blower. Airflow still drops off, but not as much as with a PSC blower motor. A few systems use an external pulse width modulated signal to the motor to create a feedback loop that maintains an external measured system condition, such as static pressure in a duct system. 

NIOSH Safety Resources

The National Institute for Occupational Safety and Health (NIOSH) is the federal agency responsible for conducting research and making recommendations for the prevention of work-related injury and illness.

The NIOSH web site has many excellent safety resources that your students can view or download. The site is large, so finding what you are looking for can sometimes be difficult, but it is worth the effort. You can find many excellent publications in their  directory of publications. Click on the “Directory of Publications and Products” link on the bottom left side of their main page. There is  a search bar to enter subjects you want to research. These are all free to download or view. Smaller documents can make excellent class safety handouts. Larger documents are more like small text books. For example the Electrical Safety Student Manual is really a book in pdf form. It is really good. One word of caution -  it shows graphic pictures of electrical burns and injuries, not cartoons. However, I find that after viewing the results of a severe electrical burn, students are far more likely to be careful in the lab.It is really too big to print and hand out, but it can be downloaded and shared as a pdf, allowing students to view it on a computer.Other publications available through the NIOSH site are

Electrical Safety Page

Protecting Worker from Heat Illness

Pocket Guide to chemical Hazards

NIOSH Safety Videos

Arc Flash Awareness Video

NIOSH Fact Sheets

   

Document Your Abilities

It is common for people who work in the HVACR industry to have very little documentation showing their proficiency. Many have never been to any formal school, others started and did not finish. Although there are now many certified techs, there are more that are not certified. This does not necessarily mean that they cannot perform their jobs, but that they have not taken the time to document their abilities. Often, the explanation is “I have been doing HVACR for 15 years and that is worth more than any piece of paper.” I would be the last to suggest that experience does not count – it does. But without a diploma or certification, how does a prospective employer know what you can do? In a tight job market, credentials matter. Many places examine resumes first to determine whom they want to interview. With no credentials, your chance of even getting an interview is slim. If you are one of the many HVACR workers without credentials, my suggestion is that you make documenting your abilities a priority. Chances are, there is a school somewhere near you that teaches HVACR. I am not suggesting that you quit working to go to school. It is often possible to do both. If you do not have any professional certifications from NATE, RSES, or HVAC Excellence you should work on obtaining professional Certification. Yes, it can take some time to go to school or study for a professional certification exam, maybe even a matter of years. Rather than focus on the length of the road, concentrate on the destination. One or two years will pass whether or not you are doing anything to improve your position. The question is, at the end of the time, where will you be? Will you be graduating with a diploma that documents your ability and opens doors, or will you still be right where you are today?

Everybody Wins!

This past week I had the pleasure of attending the Alabama Council of Air Conditioning and Refrigeration Educators, or ACARE. The meeting was held at the Alabama Power training center, in Verbena, Alabama. The training room was full with approximately 50 HVACR instructors attending. Not only were there people from Alabama, but also Georgia, Mississippi, and Arkansas. ACARE is a great example of what can be accomplished through cooperation between industry and educators. The meeting could not have happened without the help of Joel Own and Alabama Power, but the instructors are taking a very active role in making everything happen. Instructors set the program and invited the speakers. They put together an impressive Alabama Power discussing the COVER approach to troubleshooting, Harold Nelson from Mingledorff’s  discussing compressor failures, a tech forum with manufacturer’s service reps, Jeff Marques of Air Engineers showing off the new Trane Hyperion air handler, Chris Mohalley of Genteq on ECM motors,  and me showing MyHVACLab. Harold and Chris both came fully loaded with handouts including books, powerpoint presentations, and manufacturer’s specifications. The handouts were worth the trip! The instructors received training in the latest technologies and Alabama Power lightened their load in the future, both literally and figuratively. Encouraging the development of HVACR Training programs in their state will produce more capable HVACR technicians for the future of Alabama. This translates into fewer problems with systems and energy saving savings. The state of Alabama wins two ways – they save on both education and energy costs. Suppliers such as Mingledorff’s make more money on customers with educated technicians because they don’t have to spend as much money on tech support and warranty. The instructors also are able to learn from and help each other. In times of economic stress, it really makes sense to help each other as much as possible because everybody wins.

The Dark Side of Cell Phones

Several months ago I wrote about the power of smart phones and how they can be used as a service tool. Properly used, phones can save mechanics a great deal of time. Unfortunately, they can also create problems. Many people that have grown up with cell phones are used to interacting with them continually, and that can be a problem in a service business. It is never appropriate to answer your phone when you are talking with a customer. It does not matter if it is voice or text, diverting your attention away from the person you are talking with is simply rude. If that person is a customer, the sin is compounded. Before you go to talk with a customer, turn your phone off. If you are accustomed to having your phone on all the time, it can be difficult to remember to turn it off before interacting with customers. I have been guilty myself. I once had my phone ring during a lecture that I was giving. I now try to get in the habit of checking my phone before I lecture. This advice also goes for talking with your coworkers and supervisors. A very talented student of mine lost his job because he was texting during a company meeting. The problem was not just that one incident, it was simply the straw that broke the camel’s back. Most places of business will expect your undivided attention when they are trying to talk to you. Similarly, customers expect your full attention. After all, they are actually paying for your attention. There can also be a safety aspect to phone use in a field that has many real physical dangers. You should focus your attention on whatever you are physically engaged in. Failure to do so can be downright dangerous. There are many articles on the web discussing cell phone etiquette. The Huffington Post has fifteen suggestions in an easy to digest list. But please finish your conversation with your boss before clicking on the link.

A Weighty Matter

One day while I was setting up for a lab I noticed that two of my scales did not agree. What was worse, the discrepancy was significant, enough to make a system charge way off. One of the advantages of using electronic charging scales is the confidence that you have put the correct amount of refrigerant in the system. If you don’t trust your scale, you lose that advantage.  I got a third scale to try and determine which was correct, but then I thought, how do I know ANY of these are right? Maybe I have two incorrect weights, not one. So I visited my friend Jimmy in the physics lab and asked for a weight. He gave me a 2 kilogram weight. I placed the 2 kilogram weight on the scale that I suspected of being off, and it weighed 2.3 kilograms. I then moved the weight to the scale that I thought was correct, and it read exactly 2 kilograms. This restored my confidence in my good scale and verified my suspicions about the bad scale. While this simple test does not replace NIST certification, it is a simple way to keep an eye on the accuracy of your digital scales and maintain your confidence in their readings. I do not believe most  digital charging scales can be calibrated in the field, you have to send them into the manufacturer. But you can periodically check their accuracy. You may be wondering why I chose a 2 kilogram weight. Well, physics teachers work in SI, not inch pounds. Jimmy does not have any 2 pound weights. Nearly all science today Is done in SI units, not English units. If your school has a physics lab, you might want to pay them a visit. They have lots of cool toys. After all, air conditioning is really just applied physics. 

Verify

How do you know if your students have actually learned the material? Most teachers verify the results using tests. You check the student’s knowledge against a standard. If the student falls short, you provide some remediation and then test again until they meet the standard. In education, you would not assume that someone has mastered a subject simply because they read a book that had all the material in it or attended all the right lectures. You verify that they have learned the material using written tests, lab exercises, or some combination of both. How do you know that an air conditioning system performs efficiently as designed by the manufacturer? For many people this has involved using design using tools like ACCA Manual J and D, and installation using skilled personnel. These two steps are certainly important, but they can be compared to reading the book and attending the lecture. Without testing to verify your results, you really cannot be sure that the system is performing correctly. After installation, system performance should be verified by testing crucial system operating characteristics. The 2010 ACCA Quality Installation Standard provides a good format for keeping track of all aspects of a quality installation that need verification. Verification is becoming a very big deal in our industry. Increasingly, energy codes, utility rebate programs, and government programs such as Energy Star are insisting on performance verification. It is no longer enough to install a high SEER unit, you must now test and seal the ductwork and test system performance against manufacturer specifications. You can download the ACCA Quality installation Standard from their website https://www.acca.org/industry/quality/quality-installation

We the People

Happy Birthday USA! We celebrate July 4^thas the start of our nation. More correctly, it was the official start of the rebellion with the Declaration of Independence. We would not be the United States of America until nine out of the 13 states had ratified the United States Constitution. The Constitution was signed on September 17, 1787. However, it stipulated that it had to be ratified by 9 of the 13 states before it would take effect. Some states were concerned that the Constitution did not specifically reserve powers not mentioned in the document for the states. The Bill of Rights was proposed as a solution. If these states would ratify the document, they were assured that the Bill of Rights would be quickly passed. On June 21, 1788, New Hampshire became the ninth state to ratify the document, and it was subsequently agreed that government under the U.S. Constitution would begin on March 4, 1789. On September 25, 1789, the first Congress of the United States adopted 12 amendments to the U.S. Constitution--the Bill of Rights--and sent them to the states for ratification. Ten of these amendments were ratified in 1791.

The point of the brief history lesson is that the whole process from inception to the start of the first congress was based on representation. The US Constitution starts with the phrase “We the people…” Not we the chosen, we the wealthy, we the powerful, or even we the elect, but we the people. Elected representatives wrote and signed the Declaration of Independence. Elected representatives wrote and signed the Constitution. Elected representatives in all 13 colonies eventually ratified the Constitution. And finally, elected representatives voted on the Bill of Rights. All were elected representatives from their respective colonies. The men that signed these documents put their lives and fortunes in peril. Had they been captured by the British, they would have been tried for treason and hanged. Had they lost the revolutionary war, they would have lost all.

My challenge to all of you is to learn more about your country. A good place to start is at the links in the article above. And during the next election, learn about the candidates and issues and vote. To remain we the people, we the people have to participate.

Locking Refrigerant Caps Now Code

I want to point out a relatively new provision of the International Mechanical Code and the International Residential Code – a requirement for locking refrigerant caps. In the International Residential Code the provision reads “M1411.6 Locking access port caps. Refrigerant circuit access ports located outdoors shall be fitted with locking-type tamper-resistant caps.” Since the IRC has become so common across the country, there is a good likelihood that your area requires locking access port caps. If you are like me, that may come as a surprise. The primary reason for the requirement is to discourage people from releasing the refrigerant and huffing it to get a quick high. Before you all go out and start snorting refrigerant, let me first tell you what it does. Basically, it deprives you of oxygen and you feel lightheaded and dizzy as a result. That is all the high is - dizziness from oxygen deprivation. Since it deprives you of oxygen, too much for too long and you die. Since refrigerant is heavier than air, once you have filled your lungs with refrigerant, it is hard to get it to leave so you can replace it with air. I first heard of this way back in the ‘70s when people would do just about anything, including smoking bananas and sniffing refrigerant. I thought it had gone away with so many other crazy ideas of the 70’s. However, there is an alarming increase in the number of people sniffing refrigerant. The mother of a teenage boy who killed himself huffing refrigerant has founded an organization called UPROAR which works to prevent similar tragedies. So where can you get these caps? They are available at wholesalers and also online. You can read more about them at NOVENT, or AirTec.  Here are a few links to different tragic stories where people died from inhaling refrigerant.  

UPROAR - many stories on this site.

Coral Springs Florida

Dust Off

Inhalent.org

Are You Becoming Obsolete?

There is certainly a lot of change taking place in HVACR! New refrigerants to replace old standards and  even newer refrigerants to replace the new refrigerants. Variable capacity compressors, communicating control systems, and communicating thermostats that look like an I-pad. It is tempting to say, no thanks, I will just stick with my R-22 units with single speed compressors operated by contactors that are controlled by mercury bulb thermostats. And yes, many of those are still around. However, if you choose to specialize in only retro technology, you are choosing to become obsolete. Technology changes whether or not we want it to. If your job is to install and service air conditioning equipment, you need to be familiar with what is current, or eventually you will be out of a job. I remember many years ago a technician in a parts house declaring that he simply refused to work on heat pumps. He basically was saying it was too much bother to learn about them, so he would just keep working on natural draft gas furnaces and air conditioners. He would not be doing much today because most the systems in this area are heat pumps and the rest are induced draft furnaces. What he was comfortable with just does not exist anymore. As technology changes, we have to adapt. Studying is just part of a technician’s job. I read about what is going on in the HVACR field almost every day. There are so many resources now. My favorite is the RSES Journal, but I also really like the Air Conditioning Heating and Refrigeration News. I will even pick up a book on occasion. Yes, I realize that reading printed material is somewhat old school, but both publications also have on-line articles. And there are always blogs. If you prefer face to face, find a local RSES chapter. The point is we all have to be students to stay current. Otherwise, we become as obsolete as mercury bulb thermostats and natural draft furnaces.

Are You Working Hard?

The summer heat is upon us. I truly hope you all are busy. Busy is good. It certainly beats not having anything to do. However, have you ever wondered how much of your business is tied to the way you do things? Although nobody can give you any more time, you often can use your time more efficiently, which has the same effect. Learning to use your tools more effectively is important in any field. One example in teaching is designing, giving, and correcting tests. I have had quarters where at the end of the quarter I would have a box that a case of 10 packs of printer paper comes in full of paper tests to grade. I emptied it out printing the tests, and then filled it again after the tests had been taken. I still give written finals, but all other tests are on line. Using the test database built into MyHVACLab, I can build a test quickly. Better, I don’t use any of my time or any class time taking the tests. Best, I don’t have to grade a huge box of tests every few weeks. Even if you want to write all your own questions, keeping them in a test database still makes sense. You don’t duplicate effort because you can re-use your own questions. Even for my written finals, I use the database to generate the test. Instead of using class time having my students take tests, I try to use the time going over tests that they have taken. Nothing sears a piece of information into your brain like learning you just missed it on the test. Tools can be the same way. You can keep on doing the same things in the same way even when there is a more efficient way to use the same tools you already use. I have met many people who did not know that the “extra” lines inside their gauges were saturation temperatures. Essentially, a PT chart built right on their gauges staring them in the face. Digital gauges take this to an entirely new level of accuracy and flexibility, but even analog gauges normally have a few of the most common refrigerants on them. Spending a little extra on truck stock can save a lot of time. If you have the parts you need on your truck, you can do two calls in the time it takes to diagnose the problem, go get the part, and then return to put it on. Whatever you work hardest at, spend a little time analyzing why you do what you do and asking if there is not a more efficient way. The time you spend will be saved many times over.