Dry R22 Units

I got my first look at a “dry” unit the other day. A wholesale house had one on its showroom floor with a big sign “we have dry units!” I looked at the nameplate to see what it said about refrigerant. A refrigerant amount was actually listed. Instead of the familiar “factory charge” preceding the refrigerant quantity, it had “Field Charge” and then the amount. I asked about coil matching for older systems. They recommend 1/2 ton smaller condenser than the original for heat pumps and the same size condenser for air conditioning. Then I asked about warranty and they said the units came with a 5 year compressor warranty regardless of the coil connected to it. They pointed out that this was less than the warranty on new matched equipment. Many of the units are being sold to replace condensing units that have been stolen or chopped up in place, often in rental property. Another wholesaler requires you to take coil measurements and then uses software to try and figure out the coil SEER. If the calculated SEER is less than 13, they recommend against buying the dry unit. Companies that just a few years ago were cautioning against the perils of mismatches units are now selling units that will almost certainly be mismatched. They cannot provide any meaningful charging chart without knowing what coil is on the other end of the system.  

If you do decide to install a “dry’ unit, make sure and follow good refrigeration system installation practices. The fact that you are creating your own special blend of equipment makes it all the more important to be careful, not careless. It would be wise to treat the job like a compressor burnout. Flush the lines and coil, install a filter drier, pull a good vacuum, and weigh in the charge using an accurate digital scale. You can see more about line flushing at Mainstream Engineering. They sell a flush designed for this type of use. You will need to adjust the data plate charge for line length and possibly coil mismatch, but the nameplate charge should be in the ballpark unless you have very long lines. I think it might be wise to start a little under, so I would not adjust for line length until after starting the unit.  I found a good set of instructions for installing dry systems online provided by Century, a supplier that is offering dry units. No, these are NOT the folks who suggested the 1/2 under ton heat pump coil adjustment. The link to the guide is:

http://www.centuryac.com/DryChargeInstructionsandchart.pdf

Spring Fever!

Spring is always a busy time for events and meetings. The state SkillsUSA Championships are going on across the country. I spent the day this past Friday at the Georgia  International Convention Center in Atlanta viewing the competition. Shumate Mechanical provided all the judges for the HVACR competition. I was very impressed by the way they interacted with the students encouraging and teaching them. Kudos to Shumate for going out of their way to help with the SkillsUSA Contest. I was also impressed by the poise and professionalism of all the contestants. It is not easy to work under a microscope with judges and spectators peering at you while you work. They only had 18 minutes to complete each task, adding to the stress level. But despite these pressures, they all held up admirably. Along the way, the students competing learn more than HVACR skills, they learn something about themselves. Taking up the challenge and seeing it through requires a lot of effort above and beyond the normal demands of most HVACR programs. I was very proud of the preparation and hard work Keith Watermann from my program put into the competition and his hard work showed. The winners of the state contests will meet in Kansas City later this summer June 19-24  for the national championships. 


The National HVACR Educators and Trainers Conference starts Sunday, March 20^th in Las Vegas. However, if you are not registered already you will miss it because it is sold out. I spoke with Howard Weiss, and he said he hated to keep people out, but they have reached the maximum number of people the fire code will allow in the room! If you are lucky enough to be registered, be sure and say hello to David Skaves, my writing partner on Fundamentals of HVACR. He will be at the Pearson booth and he will be speaking at 9:15 on Monday on Strategies for Connecting with Today’s Student in the Age of Electronics. 


If you missed the Las Vegas show, you can still catch the HVACR & Mechanical Instructor’s Workshop in Landsdowne, Virginia at the National Conference Center. This longest running HVACR Instructor’s workshop was started by ARI and today is supported by an impressive list of industry heavy hitters including AHRI, ACCA, ACTE, CARE, HARDI, HRAI, NAOHSM, NATE, PHCC, RSES, SkillsUSA. It is March 23-25 and there is still room. It is too late to register online, but you can still register at the Conference Center. The Conference is free if you stay at the National Conference Center. There is a $65 per day fee if you are staying elsewhere. Freddie Williams will be there at the Pearson booth. He is the author of the MyHVACLab material. Freddie is the man to talk to if you have questions about using online material in your program. Besides being the author of MyHVACLab, he has extensive experience with both Blackboard and Angel. If you cannot go to anything this year, just remember next January to start planning your strategy for attending one of these events. It does take some planning, but it is worth the effort.  

I-Phone, The HVACR Service Tool of Today

Do you have an I-Phone on your list of required service tools? I can not help but notice the increasing number of students in my classes that regularly use smart phones, I-Pads, and laptops. One student brings in his I-Pad and follows along on MyHVACLAb while I am lecturing. However, creative phone use goes well beyond using MyHVACLab. Students are looking up compressor data, working with PT charts, comparing different gauge sets, and pulling down articles posted on the web. I-Phones, Androids, and  I-Pads are not really phones, they are hand held computers that are always connected to the internet. Oh, and they can be used for phone calls too. So while discussing PT charts, superheat, and subcooling I notice that four or five of my students are looking at their phones rather than the chart I am displaying. Why? They are using the free Bitzer app that puts a PT chart on their I-Phone. When discussing different gauge sets, one student shows me different models he has found, asking about the pros and cons of each. Copeland has just announced that they have released an app that gives a complete reference of their compressor data. Add to that the many smart phone accessible standard web pages with service data and you start to see that a smart phone really becomes a very useful service tool, connecting the technician with more service literature and data than could be carried around in printed form.  More than ever, I see the job of the instructor as teaching our students how to intelligently use this information. Having access to a mountain of information does not make you a technician. You have to sort out the useful form the junk, and you need to know how to apply the information to solve problems. It is more important that students understand how to use this information than it is for them to memorize any particular piece of information. Rather than restrict the use of phones in class, I allow students to use them so long as it is not for texting their girlfriend. Allowing students to use their phones in class can be a little intimidating because you realize that you do not completely control the flow of information. That is OK. I do not see my job as one of stuffing information into my students craniums. That is their job! I try to think of myself not as a walking air conditioning encyclopedia, but as a coach whose job is to get the best out of each member of my team. I need to figure out where the gaps in understanding are and guide each student to improve their understanding of the information. If you allow phone use in class, inevitably someone will be texting their girlfriend rather than looking up compressor data. They are easy to spot. They don’t ask any questions or participate in the general discussion. The HVACR app masters are looking up PT charts for some refrigerant you never heard of before, pummeling you with questions and sucking in information at a breathtaking pace. The next generation of technicians is adapting the tools of their generation to the problems they face today. Smart phones are the service tools of tomorrow today. 

Consensus Appliance Agreements Act

In the February issue of the RSES online Journal John Iwanski discusses the current proposals for the Consensus Appliance Agreements Act and new Energy Star standards. These are still proposals, not law, but they could definitely have a major impact on our industry. The most significant thing I see is that efficiency minimums would be different for different sections of the country. An 80% furnace would be legal in Georgia, but not in Maine. Or more interesting, Arizona would have different standards than Colorado or Texas. A number of industry organizations were involved in the negotiations, among them AHRI. The EPA is also proposing changes to the Energy Star program. To read more about the Consensus Appliance Agreement Act or the Energy Star proposal, go to

RSES

Actual Bill

Energy Star Proposal

Positions of Industry Organizations

PRO

       ASE Alliance to Save Energy

       AHRI Air Conditioning Heating and Refrigeration Institute

CON

      HARDI Heating Air Conditioning and Refrigeration Distributors International