Month: March 2017

 

I was sitting in a session at the HVAC Excellence educators conference (which was excellent by the way) and my phone buzzed. So like a typical punk kid I looked down at it to see that my friend Josh had sent me a Facebook message asking if we served the East side of Orlando because he wanted an A/C maintenance on his home. I told him that we did not serve that part of town and I didn’t think anything else about it.

Then yesterday I see this post

So we go out to look at it, and sure enough. The system is BARELY low, like 3 degrees of subcool low and we added 1/2 of a lb of R22 (weighed in) and did a leak detection. Yes, there was a TINY leak in the evaporator coil so Josh will probably end up getting a system at some point… However, the other tech did not do a maintenance at all, he did not quote a coil or anything other than a system. He literally showed up, saw the unit was 14 years old, pulled out his leak detector, found a hit and wrote up a proposal for $5400.00. He tried to close the “deal” right on site. No load calculations, no looking at the ducts, just a leak detection, a proposal and run.

How many 14 year old units have zero leaks?

He didn’t clean the drain or the condenser coil, he hardly even checked the charge. Heck, Josh has a UV light that wasn’t even working due to a simple loose connection, he didn’t even look at that.

Unfortunately for this company, my friend Josh is a local consumer advocate who goes on local TV news REGULARLY to talk about ways to save money and EXPOSE SCAMS. I bet you can see where this is headed.

HOW DOES THIS HAPPEN?

The standard narrative is that there are just a bunch of greedy scammers out there trying to take advantage of people. Clearly this is true sometimes, but many times the story is longer and sadder than that, often this type of thing happens when well meaning people get worn down.

Tell me if this sounds about right.

A new tech get’s hired into the trade, maybe he has some schooling maybe he doesn’t, either way he get’s his EPA license and starts riding around with another tech. The tech he rides with spends most of the day complaining about his boss, dispatch, other techs, customers and politics but almost no ACTUAL training. When they arrive at the job there are two main objectives

#1 – Get in and out as quickly as possible with as little work as possible.

#2 – Sell as much as possible during that short time. This can be hard start kits, capacitors and surge protectors some places, IAQ products others and some it’s always finding a way to push a new system. For many, it’s all three.

Usually this makes the new tech feel at least a little uncomfortable but this starts to fade as the days of riding around whining broken by short stints of selling continue.

After a few months the new tech is put into a van with some parts, pamphlets, invoices and proposal forms and set loose on the world. If he is smart, he realizes pretty quick that when his bosses talk about customer service what they really mean is making as much money as possible in a day with as few customer complaints and call backs. Usually, the easiest way to do that is to condemn everything , when a system is replaced nobody ever knows if your diagnosis was correct or not. When you do a PM there is always something you can point to as a major issue that gives you an easy out, cleaning after all does not ring the register.

Techs justify their behavior

When I was still in trade school back in 1999 I participated in a skills challenge against other students from schools across Florida. There was another guy who was already working in the field and I remember him saying “I never just change one part, I change as many as I can and the customers never know the difference and their unit will last longer”. I was appalled then as I am now by this type of thinking but I’m pretty sure he honestly believed he was doing the right thing. He had been brainwashed into thinking that this was what being a technician meant.

So this all begs a question, who is to blame and what can be done about it?

The Root Cause

 It is just easier to make money when you focus on selling instead of technical excellence. You can be great at what you do and still not make a profit but when you FOCUS on profit at every level you will usually make more of it…. for a while.

I actually blame the quality techs and companies who don’t charge enough for what they do as one reason this happens.

I have been one of these contractors for years. We squeaked out a meager profit every year driving used vans, using cheap tools, trying to make ends meet and praying the vans don’t break down. All the while, the sales focused businesses have new trucks and spiffy, clean uniforms.

The good guys need to stand up and stop apologizing for what we charge and what we do. we need to CHARGE for the high quality maintenance we do so that we actually make a profit on it. We need to diagnose the whole system and make quality recommendations to our customers based on the solid and complete diagnosis we perform. There is no reason we shouldn’t be able to afford quality tools and a well stocked van if we are the ones WHO ACTUALLY KNOW HOW TO USE THEM.

Instead we beat one another up on price and undercut one another, calling another good, quality company who charges more a “rip off” or a “scam” just because they have their pricing figured out to where they can actually make a profit.

This company who went out my friend Josh’s  house was going to charge $5,400.00 for a Lennox 3.5 ton 14 SEER Heat Pump system, that isn’t a crazy price but to some it may be seen as a “ripoff” because they would charge $4,500.00. We might charge $6,000.00 for the same system… with a new return liner, and line set, installed with nitrogen flowing, evacuated to 300 microns, with a proper load calculation, permits and a perfectly weighed in charge confirmed by manufacturers specs to a proper subcool.

The “Ripoff” is the one who doesn’t deliver on their promise, not the one who charges more.

What to do About it 

If you are a manager or owner of a company make sure you are supporting your techs to get more TECHNICALLY sound and support them to use those legitimate technical skills to translate into profitable repairs and quality workmanship. Communication skills are key in a residential tech, a tech who understands IAQ like the back of his hand will naturally sell more IAQ products, a tech who understands air flow and duct design will sell more duct upgrades and the tech who understands complete system performance will make more needed repairs. This is long road and there are no shortcuts.

If you are one of the good guys let’s band together, keep our heads up and charge enough to have a good life.

— Bryan

Photo Courtesy of Emerson

What is Cascade refrigeration?

Cascade refrigeration is a term you will hear more and more over the coming years, and while some of the systems may be very complex, the concept is actually pretty simple.

Some refrigerants are well suited for high and medium temperature applications, and some are better suited and for a lower temp applications. In a cascade system the high/medium temp refrigerant circuit is used to cool the condenser of the low temp circuit by way of heat exchanger. In essence, the condenser for the low temp system is also the evaporator or part of the evaporator of the high/medium temp system.

In the diagram above the medium temp circuit is used in the medium temp cases and is ALSO used in the heat exchanger to condense the refrigerant in the low temp circuit.

There are many reasons for this type of system but one of the big reasons is it is a practical solution for using CO2 (R744) as a low temp refrigerant.

— Bryan

 

There are many acceptable methods for making a wire splice and you need to consider many different factors when making a splice. Here are a few considerations.

  • High Voltage vs. Low Voltage – If the connection is 24V or less it USUALLY has fewer NEC (National Electrical Code) rules and regulations about how the connections are made and in some cases you are safe making an inline splice without a box. When making an inline splice on high voltage conductors you MUST use a properly UL rate splice or a box.
  • Dry vs. Damp Conditions – If it’s ever going to be exposed to moisture you need to think about shorting and corrosion. Your splice should keep water away from the conductors themselves. if there is any chance of moisture.
  • Concealed vs. Accessible – If you are going to bury the splice in the ground or in a wall it needs to be RATED for that purpose and you need to be darn sure that splice will last as long as the conductor itself.
  • Quality of Connection – Every connection needs to be good, but in cases like communication or AV wires it needs to be PERFECT. Think of that new high efficiency, super fancy communicating HVAC system you are installing. Those comm connections need to be good.    
  • Tension the Connection is (or may be) Under – In other words is the wire stretched or is there a chance it might be stretched or pulled later. For example, if a splice is going to be pulled inside a conduit, there is a good chance it will be pulled out someday. If the next guy tries to pull it out and it comes apart, your name will be cursed.
  • Aesthetics  – If the splice looks like a hunk of junk, it will be assumed it is a hunk of junk by everyone who sees it. Neat workmanship matters.

Here are a few options for splicing wires depending on application –

Bad Options 

Splicing any high voltage conductor in an “open” manner or in way that is not specifically rated. In most cases get a UL rated connector and make the connection inside a UL / NEMA rated rated box or assembly.

Making a splice by just twisting wires together and putting electrical tape on top. Just don’t.

Using wire nuts and creating a big ball of wires and running electrical tape over them until it looks like a giant blob of tape.

Good Options

Use wire nuts on low voltage or control wire in dry and accessible conditions but twist them so the wires stay neat and lay half of the conductors in one direction and the other half in the other direction and tape up in a neat fashion.

The same type of configuration with 3M Scotchlok crimp connectors for better moisture resistance than wire nuts.

In some mildly damp conditions you may be able to use self fusing silicone tape for a more water resistant layer than electrical tape.

Use butt end connectors on stranded wire or if using small gauge single conductor wire (like 18ga stat wire) you can double the end of the wire over before making a crimp. When making a crimp ensure that that the actual crimp is made on the side of the connector OPPOSITE  the seam. Once you make a butt end connector pull HARD on it totect and ensure that no bare wire is exposed outside of the insulator.

Better Options 

Use heat shrink butt connectors and stagger the connections to reduce the bulge. Heat the connectors to seal them, then run a piece heat shrink over them all. I found this 4:1 shrink ratio, marine grade heat shrink that should do a great job or water proofing. Heat shrink can be a real life saver and you can use a heat gun or a small butane torch to heat it up. Coincidentally they also make little, portable butane soldering irons as well.

For better connection quality and strength… that’s when you may consider the fabled NASA Splice!

When making a soldered splice make sure to use rosin core solder and wipe off the rosin flux before covering the splice to help prevent corrosion. Remember to run the heat shrink over the cable and the individual conductors BEFORE you start making the splices to prevent sadness and yelling.

Best Options

The best options are to just run a new wire or make the connections inside of a rate box with proper connectors. Sometimes the best way is the simplest way.

 

— Bryan


Most motors are designed to set amount of work, usually rated in either watts or horsepower, which is just 746 watts.

Watts law states that Watts = Volts x Amps. If a particular motor need to do 1 horsepower of work at 120 Volts it will draw about 6.22 amps. And yes in an inductive load like a motor it’s not quite as simple as VxA=P but we are keeping it simple here.

A motor designed to do the same amount of work (1HP) at 240v will draw half the Amps (3.11).

This does not make the second motor “more efficient” because the power company charges by the Kilowatt NOT by the amp. 

If you take a load that is designed for a particular voltage and you DROP the voltage it will also decrease the wattage according to Watts law as well as decrease the amperage according to Ohm’s law (so long as the resistance remains the same).

Let’s say you take a 5KW heat strip that is rated as 5Kw at 240v and you instead connect it to 120v.

It would then only produce 1.25 kw and draw 1/4 the amps, this is because while we may call it a “5 Kilowatt heater” it is actually just a fixed resistor designed to do 5 kilowatts per hour of work in the form of heat at 240 Volts. Cut the Volts in half you also cut the amps in half the and you decrease the amount of work done down to 1/4.

Does that make sense?

— Bryan

P.S. – It gets more complicated in inductive loads because the resistance isn’t constant but you need to understand the above first.

The suction line accumulator is designed to keep liquid refrigerant from entering the compressor while still allowing for oil return.

The trouble is that if the oil return port/screen clogs the accumulator can fill with oil and actually cause the compressor to fail. In addition to that, it can also hold contaminated oil in a burnout.

As standard compressor replacement practice, you may want to consider removing the accumulator and dumping / properly disposing of excess oil to both remove contamination and check for excessive oil buildup as well as acid testing the oil.

In the case of a bad burnout, it may be best to replace the accumulator completely in addition to the other burnout protocol measures.

— Bryan

I have spent the last few days checking run capacitors on various systems with several different meters and this is what I found.

#1 – Comparing Start wire amps against Run + Common under the clamp together is meaningless as a practical test.

I used this test on 3 different systems with 3 different meters and came to the same conclusion, whether the capacitor is way too large, way too small or the right size, made no repeatable difference in the reading no matter how we read it.
Even if this is a valid test (which I cannot confirm at this time) the difference is within the uncertainty tolerance of the meter so it’s not useful for field testing.

#2 – The under load test does work (If your meter works)

reading the amps at the herm (compressor start wire) terminal multiplying by 2652 and dividing by the start voltage (herm to c) on the capacitor does work consistently on the compressor and the fan motor however some meters are less accurate at lower amperage readings so that may make a slight difference.
#3 – Power Factor works as a test but it’s a small change
I tested several systems with the Testo 770-3 in power factor mode by installing too large and too small capacitors. The power factor did decrease in all cases when the incorrect size was installed but in some cases the difference was very slight (from 1 to .99 with a 15 mfd too small run capacitor in one case). This means that while it is a valid and useful test it may not be sensitive enough to act as verfication that a capacitor is slightly outside of allowable specs.
— Bryan

The week of 3/5/2017 was “Business week” on the HVAC school podcast and we talked about a full range of business topics. Here are our business related episodes.

As always if you have an iPhone subscribe to the podcast HERE and if you have an Android phone subscribe HERE


Why Maintenance Agreements Matter and How to Make Them Work w/ Ruth King

In this episode Ruth King shares some of her top insights on how to create a maintenance program if you don’t have and how to fix the one you have if it is broken (and how to know).

If you are interested in Ruth’s maintenance program course you can find out more HERE and be sure to use the offer code HVACRS (with all caps) to get a 10% discount on all her products.


Should I Start My Own Business? (and other solid advice) w/ Tersh Blissette

Tersh and Bryan were both techs working for other companies when they started their own businesses. This is a look back at what they got right, what they got wrong and the top things that have worked over the years.


Profitability and Money Leaks in HVAC w/ Ruth King

In this episode Ruth breaks down some of the main things an Air Conditioning contractor needs to consider when looking at their numbers and some of the major leaks that can lead to unprofitability.

You can see all of Ruth’s content and courses HERE and make sure to use the offer code HVACRS with all caps for a great discount.


Creating a Business That People Want to Work for w/ Bob Gee

This is an older episode but it contains great principals for leading an HVAC business as well as some really good sales practices.

 

As always if you have an iPhone subscribe to the podcast HERE and if you have an Android phone subscribe HERE


In a previous article we covered the standard way to check Capacitors under load.

I am now going to give an even easier test.

A properly funcitioning PSC (permanent split capacitor) or CSCR (Capacitor Start Capacitor Run) motor should have a power factor of very close to 1 if they have a properly sized and functional capacitor.

If you have a multimeter that can read power factor directly (like the Testo 770-3) you can measure the power factor by reading the voltage at the contactor and the amperage at the motor common (like usual). If you are at or close to 1 power factor then your capacitor is both functional and the right size.

In the image above I have a compressor that calls for a 35 MFD capacitor and the capacitor is running right at 35 in the under load test as well as the bench test. This is why the power factor is right at 1. I installed a run capacitor of 10 MFD larger and smaller and sure enough… the power factor dropped in both cases.


So not only do I see right away that either my capacitor is failing or improperly sized, we can also see the wattage (power) in real time.

As a side note I was only seeing about a .3 amp difference between Start and run / common together when I oversized the capacitor so I may have missed the issue if I had just used that test alone.

Now, in order to see exactly WHAT is wrong with the capacitor, whether it is failing or improperly sized, you would need to do the under load test (start winding amps x 2652 / capacitor Volts) or bench test the cap and then check against motor data plates.

But as a regular service procedure this power factor feature is a time saver and gives you a unique insight into the operation of the motor.

— Bryan

P.S. – If you are interested in the 770-3 use the offer code “getschooled” at TruTechtools.com for an 8% discount

Scroll to top
Translate »

Daily Tech Tip

Get the (near) daily Tech Tip email right in your inbox!
Email address
Name