Sunday, June 26, 2016

What Quality is Your Parachute

Imagine that you are about to embark on a skydiving adventure. When choosing your parachute, where are you going to look? Are you going to be shopping at “Surplus Universe”, online from “DIY Parachutes”, or looking for a deal on Craig’s list? Not me! I want to choose my parachute at a place where everyone there has actually used a parachute and knows how they work. The reason is obvious: my life depends on that choice.

What about a NASCAR race? Would you want the cheapest car available? Probably not, because you could not compete with the folks driving real professional grade cars. No matter how good your driving skills are, you won’t even qualify if you are driving a Yugo.

You should take the same attitude when choosing your tools for any trade, especially HVACR. For a trades person, your tools are your lifeline. Poor tools limit your ability to work and can be dangerous. For example, when using a volt meter, your hands are holding the leads through which the electricity is flowing. The only thing keeping you from being shocked is the insulation quality of the leads. You do not want to be using a meter that has not been tested by an independent agency for safety. For HVACR work, the meter should have a safety category rating of at least III  and that rating should be verified by an independent agency. Further, a meter designed expressly for HVAC will offer features not found on the bargain meter, such as capacitance or microamp testing. The “Yugo” meter won’t allow you to check the flame rod circuit, hampering your ability to do your job.

Yes, the professional grade HVACR specific meter will cost more – but your life depends upon the quality of that meter. I prefer to purchase tools from wholesalers that specialize in HVACR because the people there know more about the products that they sell. Many of the employees at an AC Wholesaler have actually used those tools. AC Wholesalers also tend to carry better quality products than the discount stores. Further, HVACR wholesalers generally don’t stock anything that is dangerous to use. If you want people to take you seriously, don’t show up with a bunch of tools from “Surplus Universe.”

Thursday, June 16, 2016

Fathers Day 2016

I traditionally do a father’s day posting to my blog. This is the first father’s day since dad passed away on December 21, 2015 - one day past his 62nd wedding anniversary. He would have been 90 in January. Up until the last month or so, he got up every morning and made bacon and eggs. We used to grocery shopping together. At first he pushed the grocery buggy around, using it like a walker. Then as he got weaker he started using the motorized scooters. The last time we went shopping, I was not sure he could maneuver the scooter, so I pushed him in his wheel chair. It did not take long for me to realize my oversight – there was no place to put groceries! He could look at all the groceries, but we had no place to put them. I circled back and got a buggy. Now I was pushing dad with one hand and pulling the buggy with the other. However, I was not doing a particularly good job – which dad noticed. He offered to push the buggy. I reluctantly agreed to let him try. So I pushed his wheel chair and he leaned forward a bit and pushed the buggy. We must have been a sight! As funny as it must have looked, dad had helped solve the problem. You see, he was all about solving problems. Looking back, I realize what a blessing those outings to the grocery store were. If you pay attention, you can find meaning in the most mundane parts of life. I really miss those trips to the grocery store.

Lynn Stanfield's 89th Birthday January 30, 2015
Richard, Dad, Sally, Carter (me)

Tuesday, May 31, 2016

EPA Warns of Flammable Replacement Refrigerants

As the summer cooling season gets under way it is a good time to reiterate that flammable refrigerants should NOT be used as replacement for R-22 in existing systems. Some people are putting in R-290, which is simply propane.  A few have tried charging their systems with fuel grade propane. Not only is this dangerous, but fuel grade propane has lots of water contaminants and will screw up your systems, that is if it does not blow up. Yes, it is true that the EPA approved flammable refrigerants for a few very specific uses in systems with a very limited charge. However, these are NEW SYSTEMS ONLY! These systems are designed from the outset to handle a flammable refrigerant.

Your R-22 air conditioner of heat pump has many spark creating controls, such as relays and contactors. A leaky system recharged with a flammable refrigerant could have all the components for an explosion: fuel, oxygen, and an ignition source. The EPA has started fining companies for selling non-approved, propane based R-22 replacement refrigerants. Most have “22a” in their name. Unfortunately, there are still plenty of places to buy this stuff over the internet. A few other names include “Frosty Cool” and Eco-Freeze”. You should be wary of anyone that sells refrigerant directly to consumers over the internet.

I don’t believe regular HVACR wholesalers will have any of this stuff, and major refrigerant companies such as Honeywell, DuPont, or Arkema are not selling it either. They do each offer their own R-22 replacement solutions, none of which are flammable. Some legal replacement solutions have very small percentages of hydrocarbon components to improve oil return. Their hydrocarbon components are in such small quantities that they generally pose no threat of flammability. So what is the best thing to put in an R-22 system? R-22. Read more about the EPA actions and warnings here.

Wednesday, May 25, 2016

Daikin VRV Pro Tour

VRVProTour_Banner_Contractors.small

I took part in the Daikin VRV Pro Tour in Houston this past week. This was the first VRV Pro tour aimed specifically for HVAC Educators. The idea is pretty straight forward. There are way too few techs who understand variable refrigerant flow systems, and Daikin is trying to recruit some help from those of us whose job is teaching HVAC. The tour included a mix of class time and tours of the Daikin facilities in Houston. Daikin is making a very large investment in manufacturing and training facilities here in the US. They are serious about expanding the VRV/VRF footprint in the US. 

What is VRV/VRF? VRV stands for Variable Refrigerant Volume – and is a Daikin trademark name. VRF is variable refrigerant flow – the same idea without the trademark. The idea is to modulate refrigerant flow based on system load, and to achieve system zoning using refrigerant instead of air. Instead of ducting air throughout a building, you are piping refrigerant throughout the building. Indoor units are placed in the zones they are conditioning. Refrigerant is sent to the indoor units based on the needs of that unit. So in effect, you are zoning using refrigerant instead of air or water. 

The compressors are controlled by inverter drives, the metering devices are electronically controlled expansion valves, and the controls are communicating digital controls. Now imagine how difficult it is to find people who are properly trained to work on these, and you understand Daikin's quandary. They HAVE to ramp up their educational effort if they are to have any hope of expanding their market here. 

So did I enjoy the tour? Absolutely!
Should you go if you have an opportunity? Absolutely!
Did a two day class and tour teach me all I need to know to install and service VRV systems? Well...

If you want to learn more about Daikin products, go to daikincity.com and click on "Library" in the middle towards the bottom. That takes you to a page that allows you to download installation and application manuals for all their products.

Sunday, May 15, 2016

Condensate Drain Cleaning

It is time for annual spring AC maintenance calls. One thing you should be doing is cleaning out the condensate line and checking to see that the condensate drain is working properly. The customer is paying you for a seasonal maintenance to avoid having problems – such as a mess caused by something as simple as a clogged drain line. If you can get to the condensate drain easily, you can blow it out with nitrogen using a rubber stopper with a 1/4” copper pipe and flare connection.

Gallo Gun









Another option is the Gallo Gun that uses CO2 charges. Both of these options require access to the drain opening inside the evaporator drain pan. The drain opening is usually accessible on cased coils by removing a panel on the front of the coil casing. Likewise, the drain opening for the coil in most heat pump air handlers can be accessed by removing the front panels.


However, for coils in hard to reach places, or coils installed inside a plenum with no access panel, it may be easier to suck out the muck using a Sludge Sucker. The Sludge Sucker is installed on the drain outlet. Nitrogen pressure creates a vortex which makes a strong suction on the drain line, sucking out the water and muck in the entire drain system.
Uniweld Sludge Sucker


Foe some systems you may need to clean out the condensate line trap. If  the drain is already plugged, then chances are the trap is plugged. Most manufacturers require condensate line traps. The trap is designed to stop air from sucking in through the condensate line during operation. Unfortunately, because traps tend to trap stuff, they get blocked with crud. Most codes now require that condensate lines have clean-outs which allow the trap to be cleaned without cutting out the existing trap and replacing it. For many site built traps, this has been common for many years. The only practical way to clean them was actually to just replace them.

If you do have to cut out and replace a condensate trap, make sure that what you replace it with can be opened and cleaned. This can be done by installing tees in a couple of places where you would normally use ells and plugging or capping the unused branch. Alternatively, you can use a manufactured product such as the Rectorseal EZ Trap of the All-Access AA1 cleanout.
Rectorseal EZ Trap
All Access AA1
































Another solution would be to remove the traditional trap and replace it with a product designed to provide a drain seal without trapping water. Three types are available – the Cost Guard condensate drain seal by Trent Technologies, the Air Trap by Des Champs Technologies, and the Rectorseal Waterless Kit for their EZ Trap. I will talk more about how these work in a future post.
Trent Technologies Cost Guard

Des Champs Air Traps
Rectorseal Waterless Kit


If the system you are working on does not have a safety overflow switch installed, consider adding one. The safety switch is typically wired in series with “Y” to prevent the outdoor unit from operating and creating more water.  Some are installed in the primary drain clean-out, and some are installed in the secondary drain port. They are inexpensive, easy to add, and help prevent property damage. In the case of coils installed on top of furnaces, they can prevent the destruction of expensive electronic components inside the furnace from an overflowing condensate drain.
Rectorseal Safety Switch in primary drain

Diversitech safety switch in secondary drain


Monday, May 9, 2016

Politics Poisons Working Relationships

This 2016 presidential election promises to be an especially exciting and event-filled campaign. Many people are bound to get caught up in the excitement and fury to come. However, please do not make the mistake of discussing politics at work. People can get emotionally wrought up in their politics, causing unkind remarks that are impossible to un-say. Discussing politics at work can poison a healthy working relationship.

Several years ago a student went to work for a local company. At first all was bliss. The student talked about how nice the owner was and how much he was learning. The company owner remarked on how smart the student was and how quickly he learned. Then all of a sudden the reports changed. The student now called the owner a racist bigot and the owner said the student was lazy and stupid. Digging a little deeper I discovered the core issue: one day at work the student had offered his negative opinion of then president Ronald Reagan. He had made the assumption that because both he and his employer were on friendly terms and were polite to each other, that they felt the same way regarding politics. However, the employer thought Reagan had saved the country. The ensuing discussion left both of them so angry that the student could no longer work there. The student really needed the job, and truth be told, the company really needed his help. Both parties lost a valuable working relationship because of a casual remark about politics.

If you are an employee, offering your opinion on politics to fellow workers or your boss can jeopardize your relationship. If you are the boss, think about the effect offering your opinion has on your employees. They can’t safely disagree – so you won’t likely get honest discussion. They may quietly agree, even if they don't agree. Or, they may decide you're a racist bigot and quit. And of course you should NEVER start a political discussion with customers. If the customer starts the discussion, agree with whatever they say and get out of the discussion as quickly as possible. Who loses if the customer gets upset because of political differences? You and your company.

I know you probably feel that the country’s existence depends upon your candidate winning. But the truth is whoever is elected president will be there four years, maybe eight years. Hopefully your career will extend far beyond eight years. The president will come and go and you will still be making the world a better place by keeping folks comfortable. So what happened to the two techs in the story? They are both doing fine – separately. I am sure that they support different candidates. They each are fine men, good techs, and do our trade proud – I just won’t discuss politics with them.

Wednesday, April 27, 2016

Pressure Transducers

On my last post I discussed common refrigeration pressure switches. As the name implies, these are switches which are opened and closed by pressure changes. They can make or break circuits, but they cannot indicate pressure. Pressure transducers are often used for electronic controls because they can actually indicate system pressures.

The word “transduce” means to change from one form to another. A pressure transducer turns pressure changes into analog electrical signal changes. This is most often a change in a DC voltage, typically 0 – 5 volts DC. This changing voltage can then be interpreted as a pressure by the electronic control to which it is connected.

The most common pressure transducers used in HVAC use a small stainless-steel diaphragm with strain gauges bonded to it. A change in pressure causes the diaphragm to bend, which causes the strain gauges to change resistance. These transducers have three leads: two are wired to DC+ and DC- and the third carries the signal. Pressure transducers ohm out like a potentiometer. On diagrams this looks like a potentiometer with a pressure bellows connected to the wiper arm. The resistance between the two leads that connect to DC voltage should stay the same regardless of the pressure. The third lead changes resistance relative to the two other leads as the pressure changes.




When the two other leads are connected to 5 volts DC, the signal connection will vary between 0 and 5 volts DC depending on the pressure. The control then interprets this voltage and controls the system based on the board’s program. If you want to check the transducer signal, read the voltage between the signal lead and DC- and then compare this voltage to a chart published by the manufacturer. Here are a couple of links to more information on presure transducers

Omega Transducers

Emerson Climate Technologies