Category: Tech Tips

 

I walked into a supply house the other day and I was looking at a “universal” expansion valve on the shelf. The friendly guy behind the counter saw me and walked over, after saying hello he offered

“That’s a great valve, it’s even balanced port”.

Now I am a bit of a trouble maker, I should have just nodded and said “uh huh” but instead I asked, “what does balanced port mean?”. The counter guy sort of half shrugged and said: “I guess it means it works on a lot of different systems?”

I would bet that most people in the industry have heard the term “balanced port” and figure it sounds like a good thing but don’t really know what it does. Not long ago, I would have been one of them.

We have all been taught that there are three forces that act on an expansion valve –

  1. Bulb Pressure is an opening force
  2. Evaporator Pressure (external equalizer) is a closing force
  3. The Spring is a closing force

while the system is within its design operating conditions these forces are the primary forces at work that allow the valve to “set” the evaporator outlet superheat.

There is a fourth force and that is the opening force applied by the refrigerant passing through the needle. When the inlet (liquid line) pressure is within the normal operating range this force is accounted for in a normal TXV. In cases where the liquid pressure is higher than usual the force will be greater allowing more flow through the coil and when it is less it will allow less flow.

The result of this effect is fluctuating superheat based on liquid pressure which may be acceptable in small amounts but can become unacceptable quickly on systems that require accurate evaporator feeding or systems that have a wide swing in condensing temperatures and pressures.

Sporlan largely solved this particular issue in the ’40s when they brought the “balanced port” valve to market. While the technology is nothing new it has been improved on over time.

Balanced port TXVs can vary in design but they solve this problem by allowing the inlet pressure to affect the top and bottom of the needle (orifice) equally. This eliminates (or reduces) the liquid pressure as an opening force and instead turns it into a “balanced” force that neither opens or closes the valve.

If you have an application where the head pressure is allowed to change or “float” over a wide range, the balanced port TXV is a great choice.

— Bryan

 

 

In these tips and on the podcast we talk a lot about the importance of deep vacuum and deep vacuum using proper processes and tools is the best and really ONLY way to ensure a system is clean, dry and tight.

Just to review that means

Nitrogen purge, flow and pressurize > Cores removed > Vacuum gauge on the system > Large hoses > Vacuum pump tested > Pull to below 500 > perform an isolation “decay” test

This is all great and works just as advertised but sometimes techs can still get frustrated when pulling on systems that were previously in service or that are abnormally wet. This is when nitrogen sweeping and extra heat can come in handy.

Understand the Micron Gauge 

A micron is one-millionth of a meter of mercury column… in other words, a REALLY tiny amount of pressure and it requires a very accurate and precise instrument to measure.

A vacuum or “micron” gauge is a thermistor sensor that relies on heat transfer from the thermistor to measure vacuum level. Because vacuum is a poor conductor of heat the deeper the vacuum the less heat transferred which allows it to measure the vacuum level.

The gauge is calibrated to nitrogen or air NOT refrigerant, so any small pockets of refrigerant in the system or in the oil can interfere with the measurement.

The Challenge

When you are working on a system that previously had refrigerant in it and you recover the charge down to atmospheric pressure, there is still a lot of refrigerant in the system. The result can be an erratic reading on the gauge and “stalling” of the vacuum as refrigerant slowly escapes from the oil.

Sweeping the system with a high-velocity flow of nitrogen can help to displace the refrigerant as well as agitate the oil and help to free it up and remove it.

The same is also true with abnormally wet systems, while the nitrogen isn’t a magical sponge soaking up water it can help to get it moving to flow some nitrogen.

When running into these issues during low-temperature conditions or on systems like freezers where components are still in the cold box, it can be helpful to use a heat gun to warm cold areas or parts that hold oil such as the compressor or accumulator.

You can use heat during deep vacuum and then break with nitrogen to help the process along.

This does not replace the deep vacuum process but can certainly help it along when you find yourself getting stuck.

— Bryan


There is a big move in residential and light commercial HVAC toward measuring static pressure regularly during commissioning, service and maintenance. And don’t get me wrong

Measuring static pressure is VERY important

The challenge comes in when techs begin taking measurements without understanding where to take them, what they mean, or worse… they use measurements as an excuse not to do a proper visual, common sense inspection.

So before we go on, let’s cut to the chase. You need to visually inspect blower wheels, blower taps and settings, blower direction, belts, pulleys, evaporator coils, filters and condenser coils as well as look for any other abnormal return or condenser restrictions.

Do this BEFORE you take detailed measurements and you will save yourself a lot of time and heartache.

So what is “static pressure” anyway?

Think of the airside of the system like a balloon. Static Pressure is the inflating (positive) or deflating (negative) pressure against the walls of the ducts/fan coil/furnace in relationship to another point which is usually atmospheric pressure 14.7 PSIA (at sea level) or 0 PSIA.

When you blow up a balloon there is a positive pressure against all sides inside the balloon in relationship to the atmospheric pressure around the balloon.

Static Pressure in residential and light commercial HVAC is generally measured in Inches of water column. We often measure it with an accurate digital manometer zeroed out to atmospheric pressure before use.

Static Pressure is not airflow. You could have static Pressure and have no airflow whatsoever. If you think of it in electrical terms, you can read voltage (potential) between two points and have no actual movement of electrons. It is a measure of the difference in energy states between two points not a measure of quantity.

If you took a blower, attached a duct to it and blocked the end of the duct with a cap and turned the blower on you would have 0 CFM of airflow in the duct and very high static pressure. The exact amount of static pressure would be based on the ability of that particular blower motor and wheel to build up pressure.

So when we are measuring static we are measuring pressure in the duct system not flow.

The more powerful the motor, the more pressure it can create and the more pressure/resistance it can overcome.

Think of a blower motor like a compressor, when it is off the pressure on both the inlet and outlet are the same. In the case of a compressor the pressure when off will be the static pressure of the refrigerant (let’s say 132 PSIG static pressure for R22 at 75° ambient) in the case of a blower it will be atmospheric pressure.

When the compressor turns on the suction pressure drops below 132 PSIG and the head pressure rises above 132 PSIG. The compressor creates this difference in pressure both above and below the static, saturated refrigerant pressure.

When a blower turns on it also drops the pressure of the return side below atmospheric pressure (14.7 PSIA) and it increases the supply side pressure above atmospheric pressure.

We measure this static pressure at various points to find out how much resistance to airflow there is at various points in the system.

For example, we may measure the pressure drop across the evaporator or the filter or a particular run of duct or across a fire damper (to see if it’s slammed shut)


We also measure at the top and bottom of the appliance (furnace or fan coil) to find the Total External Static Pressure (TESP) which helps us calculate airflow when we compare to fan tables as well as helps us understand if we duct or system issues.

On a brand new, perfectly functioning system this works great.

But on an older system with a dirty blower wheel or a fan coil with a dirty coil, this no longer serves its original purpose.

If the blower wheel is dirty, the blower loses its ability to move air effectively, and therefore also loses its ability to create the pressure differential between the return and supply.

We are trained to think that low static equals good and high static equals bad

In the case of a dirty blower wheel or a clogged evap on a fan coil, the TESP will be LOW and there will still be low airflow (low CFM).

As far as the refrigerant circuit and capacity is concerned the static pressure is meaningless, it is all a matter of how many CFM of air are traveling over the coil surface area. We use static Pressure as a diagnostic and benchmarking tool when taken together with an understanding of the system, blower specs and settings and duct design. Static pressure by itself means very little in the same way that measuring voltage or head pressure by themselves mean very little.

The point of this article is not to downplay the importance of static pressure or to explain how to measure it. The point is to remind you of two important facts.

  1. Check your blower wheel, blower direction, coils, filters, blower settings and other obvious airflow restrictions and issues first.
  2. Before measuring your static think carefully about where you are placing your probes and what you expect to see / what you diagnosing with the measurement.

— Bryan

For a detailed explanation of static pressure you can go HERE

Or see a great video by Jim Bergmann using a Testo manometer HERE or Corbett Lundsford on static HERE


When tightening down a blower wheel or a fan blade on a motor shaft ONLY tighten it on the flat of the shaft.

If you have more than one screw, but only one flat surface on the shaft then only tighten the one set screw.

Also…

Refrain from over-tightening set screws, they need to bite into the shaft but you don’t need to mangle the poor thing. Both setting on the curve and over-tightening can make it hard or impossible to remove the blade or wheel later. I’ve seen this several times in high wall ductless systems where an overtightened or improperly set wheel can make it impossible to remove later. A little grease on the shaft and a carefully tightened screw can make it a lot easier for the next time.

Simple, but important.

— Bryan

WARNING: THIS ARTICLE CONTAINS GENERALIZATIONS. IT DOES NOT APPLY TO EVERYONE AND WE HAVE ALL PROBABLY BEEN ALL OF THESE AT ONE POINT OR ANOTHER. IF YOU FEEL PERSONALLY ATTACKED MAY I SUGGEST FINDING A SAFE SPACE AT A WEST COAST UNIVERSITY AND BORROWING A BINKY FROM A NEARBY TODDLER. ALSO… MY CAPS LOCK BUTTON IS STUCK.


It was my first few weeks out of tech school and I had already ridden with several guys. Some good, some not as good but today was the first time with this tech and something was already different. We were driving to our first call of the day and between dirty jokes and puffs on a cigarette.

“OK, let’s guess what’s wrong with this next one… they are all Lennox in this subdivision… so I’m betting…. a TXV”

That was my first exposure to the “Been there, seen that” tech, that relies on calibrated guesswork as a primary diagnosis tool. Along the way I’ve met many more of these and other types of techs in the “Diagnosis Pyramid” and so… I will share them with you now.

But first….

I confess I stole this pyramid idea from “Grahams Hierarchy of Disagreement” which is also one of my favorites… maybe I just like pyramids, my grandmother was an ancient alien so there’s that.


The Hack

I literally just made a podcast where I said we should stop calling people hacks. So I guess I’m a hypocrite, but hack is much easier to say than “tradesperson of dubious skills, training or intellect” so hack will need to suffice here.

Many hacks think they know what they doing because they suffer from a heavy dose of Dunning-Krueger effect and are standing firmly on Mt. Stupid as shown here.

The good news is that many confident people start here and this is not a life sentence to stay stranded on Mt. stupid. I have done complete hack jobs in my career, thinking I had enough skill, knowledge and experience only to realize later that I was a bumbling goon. The hack has to travel through the valley of despair to reach the slope of enlightenment where they can become a real tech.

Strength = Ignorance is Bliss

Fatal Flaw = They Are Terrible at Working on HVAC/R 


White Shirt

Let’s start by focusing on the good things about a white shirt:

  1. They smell nice
  2. They smile
  3. They have a firm handshake
  4. They rarely break systems because they don’t use tools on them very often

Truth is that many good techs could learn a thing or three about positive communication and people skills from a white shirt, but that is where my positive comments end.

The trouble with white shirts advancing beyond that stage is they have no incentive to do so. They don’t need to get dirty, they make lots of money and they look dang good doing it.

These are just salespeople and the more they learn technically, the more complicated it can be to sell systems so why bother?

Strength = Making Money & Looking good

Fatal Flaw = Greed 


Parts Changer 

There are two types of parts changers, the one who does it to make more money and the one who does it because he thinks that’s what diagnosis is.

In flat rate environments that pay bid time or commission on parts there are techs who catch on quick that certain repairs are money makers so they look EXTRA HARD for those repairs on every job. It isn’t to say they are purposefully looking to pad a ticket but they become fixated on certain things that bring in the most money to them.

The other parts changer is often an inexperienced or under-trained tech who throws a bunch of parts at a problem and honestly thinks that’s how you fix problems.

I knew one tech that would replace the control wire and transformer every time he a low voltage fuse blowing that he couldn’t figure out. He didn’t do it because it benefitted him in any way, he just didn’t know how to troubleshoot.

Strength = They Eventually Get The System Running (Mostly)

Fatal Flaw = It Costs a Lot and Often Requires Multiple Trips 


Been There Tech

The been there tech is common in all industries and is especially in techs who have done the job 10+ years. When you start out as a hack or a parts changer it’s often easier to end up relying on what you’ve seen before than it is to go back to the start and really understand the fundamentals of how things work.

It can be a big ego hit for a been there tech to admit what they don’t understand so they often form complex legends to explain why things happen the way they do.

Been there techs will often talk about “weird problems” and will concoct strange solutions to problems such as drilling holes places you are pretty sure they shouldn’t or wiring this or that to that other thing or bypassing that one part because “it’s not really needed”.

The been there tech should do more manual reading and less storytelling and they will find the myths and legends begin to look more like science.

Strength = They Often Have a Lot of Valuable Experiential Knowledge 

Fatal Flaw = What They Know Only Applies to What They’ve Actually Worked On. New Technology is Often Confounding. 


Average Tech 

The final four techs are all truly techs and they have more in common then they have that separate them. The majority of the techs you meet that can actually repair most problems on most machines are average techs.

An average tech generally knows how the system works, can use a gauge manifold and a meter and can figure out the location of a leak or a low voltage short.

Their focus is on diagnosing the primary problem, fixing it and getting out of there as quickly as possible. They don’t do much with superheat or subcool though they know how to calculate it, they don’t use a micron gauge though they know the “right” answer is 500 microns and they don’t really care to learn much more.

Strength = They Can Consistently Make Stuff Blow Cold and Hot

Fatal Flaw = Callbacks are Pretty Common When “More Stuff Breaks”


Senior Tech 

A real senior tech has all the find and fix skills of an average tech but with extra insight as to the “why” behind a failure. Yes the TXV is restricted but WHY wasn’t the factory drier replaced with a new one when that compressor was replaced 6 months ago?

A senior tech knows how a compressor works and what makes it fail, knows how to check combustion on a furnace and what is causing the rising CO and can spot a leaking flare fitting from a mile away.

The thing that keeps a senior tech from becoming a Supertech is the vision of more than one layer beyond the NOW cause to all of the contributing factors that are often outside of the equipment itself.

Issues like high a low humidity, sweating ducts, occupant discomfort, coils that keep leaking over and over, consistent compressor failures when all the readings look “fine”.

When issues start to spread outside of the equipment into the electrical system, indoor air, envelope, ducts and design a senior tech can find themselves frustrated.

Strength = Excellent Diagnosticians 

Fatal Flaw = Appliance Fixation 


Supertech

The term “Supertech” is often used as a pejorative to mean an experienced tech who thinks they know it all. These types of Supertech are often actually “been there” techs who like to talk on social media.

No, here I’m saying supertech as in a tech that can really fix just about anything with enough time alloted. They are nerdy enough to fill any knowledge gaps they may have about an issue before they call it good. They diagnose the entire structure and notice all of the contributing factors to problems. You can throw this sort of tech at almost any problem…. however…

They still are all about solving problems and can miss opportunities to optimize performance.

Strength = They Can Fix Anything 

Challenge = They Aren’t Always That Profitable 


Unicorn Tech 

Ok… I’m stretching here, but let’s face it… this whole thing is a bit of a stretch.

In order for a really good tech to also optimize profitability, they need to look outside of what is wrong in need of fixing and what can be improved for optimal

  • System longevity
  • Efficiency
  • Comfort
  • Indoor Health & Safety

Doing this really well is a heck of a lot more than just selling a UV light or PCO like many white shirts do, it’s about really understanding how to tune a building and equipment to work better.

This is things like dropping the compression ratio on a rack by letting the head float a little lower, or recommending that can lights be replaced with sealed led trim to reduce attic infiltration.

There are many high-value solutions that HVAC/R techs can help to suggest and implement that lead to a profitable business and happy customers.

Strength = Living Happily Ever After 

Fatal Flaw = Too Much Money that They Must Build a Tower Like Scrooge McDuck to House (Ok, more like pride in their work and good nights sleep…. leave the gold tower to the white shirts) 

— Bryan

Jesse Grandbois is one of the techs who reads the tech tips wrote a few tips that he wanted to share on some gas furnace control basics. This tip is about how to use a fancy digital stat on a millivolt system

For those of you who don’t know, a millivolt system uses a thermocouple / thermopile with a standing (constant) pilot flame to generate a tiny “millivolt” signal that is used to control the furnace rather than the 24v signal modern thermostats use.


There’s still a ton of millivolt furnaces out there and a lot of the owners want the new and fancy Wi-Fi thermostats. If you’re not sure how to get the 24v out of a millivolt system, this tip is for you.
But first let’s go over a couple basics.
You’ll be using an isolation relay. It’s just a SPST (Single Pole, Sngle Throw) NO (Normally Open) relay to separate the different voltages in a system.
Millivolt furnaces operate using a thermopile to power the system. A thermopile is simply multiple thermocouples. Some millivolt systems will also use a thermocouple for flame safety. Under load a thermopile should operate at no less than 190MV.
Please refer to the wiring diagram while reading the information below.
You’re going to feed 120v to the transformer. This is what will be used to create the 24v for the thermostat.
Wire your hot side of the 24v transformer to R on the Wi-Fi thermostat.
Connect W on the thermostat to one side of the relay coil. On the other side of the coil you’ll add C from the thermostat, and common wire of the transformer.
You’re going to take the thermostat wires off your old millivolt thermostat and add them to the NO terminals on the relay.

On a call for heat the relay coil will be powered closing the SPST relay powering the millivolt system (NO terminals) for heat.

— Jesse

There’s a moral to this story though it is a bit more of a cautionary tale than most I write. While it doesn’t rank with the story of three wise men or even Frank Capra’s Christmas classic “It’s a Wonderful Life”. You may find some common threads with both learning wisdom and remembering why throwing ourselves off a bridge isn’t the best choice like George Bailey considered doing.


The year was 2007 or maybe 2008 and it was most certainly Christmas Eve.

We are close geographically and relationally to both my wife’s family (The Claerbouts) and my family (The Orrs) and due to this we always spend Christmas eve with one side and Christmas Day with the other.

Luckily, while Florida Summers can drive an A/C tech insane, the winter and especially the holidays, tend to be quite slow. For me as a new business owner and one of the only techs at Kalos that meant that generally speaking, Christmas was a welcomed rest from a crazy year with seemingly endless hours.

As we were preparing the kids to head out to Leilani’s parents my phone rings (My cell phone WAS the emergency line).

The caller was a notoriously…. challenging… customer with many vacation homes under management. I gritted my teeth, swore inside and answered as nicely as I could.

“Brrryyyyan” the customer exclaimed, he always had a way of stretchhhhing out my name in a way that exuded disappointment and condescension.

“We have guests arriving and the POOL IS COLD… You JUSSSSSTTTT serviced that pool heater last month and now it’s NOT WORKING”

I need to step back a bit and clarify that we work on a LOT of pool heaters in the winter. Both gas and heat pump pool heating is used to keep pools over 80 degrees so that people from cold climates can vacation at Disney and swim in sauna-like temperatures even when it’s 40 outside.

It’s nice winter work for us… and I shouldn’t complain… but ever since we started doing it the term “emergency” has come to include 57-year-old, very white grandmas from Buffalo who need to take a swim after their day at Disney World and GASP! the pool is 73 degrees! Somebody better dial 911!

On this particular Christmas eve, this particular pool heater happened to be on the very far side of town, on the other side of Disney over an hour away from where I live.

Good grief! said I as I hung up the phone, looking and sounding like Charlie Brown.

So I hopped in the van and drove to the offending pool heater.

When I hopped out of the van I found the very best thing an A/C tech can find when they are in a hurry.

So I call the customer, quote the capacitor to which they respond (as they always do) “Bryyyyyyannnn, you were Jusssstttt out there… that seems like a bit much don’t you think’

Keep in mind, this customer is also British so every word carries the weight and gravitas of  Queen Elizabeth during a knighting ceremony.

Yes, that is the price

No, I didn’t cause it

Yes, I can do it now

Yes, I will leave the pool heater on

I slap that sucker in, fire it up, check amps, grab the suction line it’s cold, touch the discharge line, it’s hot, check the pool timer, look at the pool valve positions … all is well as far as I’m gonna check today and I’m OUT OF THERE!

It is now approaching noon and I’m almost home and….

bzzzzt… bzzzzt… bzzzzzzzzzzzzt

Because I’m by myself with no wife and kids I curse out loud with all the words a Christian homeschooler can think of “Poppycock and Fiddlesticks” I exclaim…

“Brrrrrrryyyyannn, the pool is SHTILLLLLLL COLLLLDDD” shrieked Sean Connery’s twin on the other end of the line in an agitated baritone.

The pool is still cold? Yes…. of course, the pool is still cold. It will take DAYS for a full-sized pool to heat up to 80+ degrees with a heat pump heater… I know this, they know this… everyone who knows anything about pools knows this.

I explain this to my dear, sweet, favorite customer in a squeaky, pre-pubescent voice and reassure them that the pool will eventually heat up but that it will take half a millennium AS PER THE USUAL, not one hour, which is all it had been since I left.

“BRYYYYYANNNNNN!!!!” the customer howled with a voice between that of Lord Voldemort and a hungry werewolf, “It is one thing for you to continue to rip us off with all these failed capacitors but quite ANOTHER for you to make excuses for a pool heater that IS NOT FIXED, you must GO BACK.”

This is the moment that this article is about…. The moment of truth and choice that separates the wise leaders, managers and techs from the reactive.

I took a breath.

I paused.

I reflected.

And I told the customer

“I value your business, I’m as certain as I can be that the heater is working as expected and it will take at least 24 hrs if not several days for that pool to reach temperature, If it isn’t warm in two days, give me a call… otherwise have a very merry Christmas.”

No…

That’s what I should have done. What I did instead was to pull over my van too fast in preparation to turn around and hit an enormous piece of tire retread on the side of the road.

Just like ralphie, I shouted OHHH FUUUUUUDDDGEEEE on the phone.

Only I didn’t say “Fudge.” I said THE word, the big one, the queen-mother of dirty words, the “F-dash-dash-dash” word!

The customer hung up on me and I was sitting on the side of the road with a big, black rubber road rash on my van and the metaphorical taste of soap in my mouth where the ghost of my mother past washed the dirty word out.

So I went back to the pool heater…

There was nothing wrong

I explained everything to the customer and apologized for freaking out.

It turned out fine

But the lesson of the story for us in the trade is that we need to be prepared for customers to be unrealistic, demanding and rude. It comes with the territory and who knows what they are going through that is contributing to their behavior.

All I needed to do was to be better emotionally prepared with what I am and am not willing to do, not with emotion, but as a clear business decision.

Many of our jobs in the field include being on-call and many customers will have a different definition of what’s an emergency and what isn’t. We are best off being friendly, clear and saying no sometimes in a polite, professional tone.

Merry Christmas and may your on-call be easy and your customers friendly

— Bryan

 

 

 

 

 

 

 

 

One aspect of motor selection that can get overlooked is motor bearings and it can have big consequences.

Sleeve bearings are most common in residential and light commercial applications because they are less expensive and quieter. They don’t have rolling “balls” but rather rely on a thin film of oil on metal sleeves.

Sleeve bearings work well when noise is a consideration and when the shaft load isn’t high which is especially true in residential direct driven blower and condenser fan applications.

Ball bearings are the best choice when the motor is under greater shaft tension or when fan speed controllers are in place. This is common in larger commercial and industrial applications especially when the motor is driving a belt that pulls on the motor shaft.

If you accidentally use a sleeve bearing in a situation where there should be a ball bearing the motor will fail early,

If you use a ball bearing motor where there should be a sleeve bearing it may be bothersome from a noise standpoint.

— Bryan

I started working as a tech when I was 17 years old, fresh out of tech school. My first winter out on my own I went to a service call in an older part of Orlando, a part of town I had never worked on before. It was an especially cold winter that year, and the service call was for insufficient heat.

 

When I arrived, I found the system was a really old GE straight cool system. After testing the system, I found the system had a 10kw heater, but only 5kw was working. After a closer look, it was discovered that 5 KW of the heat was disconnected. This was no problem for me; wiring was always my specialty! I grabbed some #12 stranded and had that puppy heating in no time.

Problem…

#1 – It smoked like a chimney and set off every alarm in the house

#2 – Once I got the doors and windows open and the smell cleared out as best I could it got me thinking… How long has it been since that second 5kw was connected?

When I looked closer I saw that the feed wire going to the air handler was only #10… then it dawned on me.

The REASON they had one-half of the heat disconnected was because the breaker and wire size were only rated for 5kw. Why did they a 10kw you might ask? Likely it’s what they had on the truck and they figured if they disconnected one-half it would be safe.

Lessons learned –

#1 – Never assume that a system was installed properly to begin with and keep an eye out for proper feed wire size.

#2 – Don’t use improperly rated heat strips or other rated parts and simply make an “alteration”. When the next technician arrives he likely won’t understand what you did. At best you confuse him, at worst you kill him.

— Bryan

Another quality tech tip from senior refrigeration and HVAC tech Jeremy Smith. Jeremy lives in Ohio so he knows a thing or three about the cold.


As HVAC/R techs, we’re often called on to work in some of the worst weather conditions. With the cold weather, I thought it timely to share some tips and strategies that I use for staying warm in the cold weather, particularly for you guys in the south who think that 40°F Is ‘cold’.

Staying warm, particularly in very cold weather, isn’t about having the thickest jacket or the most socks, it’s more about picking the right layers to wear. Let’s be honest, we’re all tough enough to gut out an hour or so in the worst conditions imaginable with a hoodie and a beanie cap. But, when we’re exerting that much mental effort just to endure being cold and miserable, we’re not exerting that effort to work on solving the problem or making the repair, so staying comfortable is both to our benefit and to our employers benefit as we’re more effective when we’re not standing there shivering.

The first and foremost rule in staying warm is to stay DRY. Wet clothing, either from your own sweat or from rain or snow that melts into your gear doesn’t insulate as well. Some fabrics, like wool, retain their insulation better, but if you get wet, you’re going to have a long, cold day. Let’s start with what’s called a “base layer” the base layer isn’t about insulation. It’s about staying dry. Under Armour is a popular brand and their stuff is great, but I go in a different direction and use Merino Wool base layers. They can be cheaper than Under Armour and perform at least as well. These aren’t Grandpa’s itchy wool long johns, they’re very comfortable, warm and they help keep your skin dry which is really the secret to staying warm.

Next, you want insulation. Fleece is good here, so is a nice Under Armour hoodie or similar item. Even a nice, thick sweatshirt is enough to keep your body warm. A vest is also helpful because keeping your body core warm is more important than keeping your arms warm. I’ve also got fleece pants for when it gets really cold but I normally don’t need them for work. Layer one or more on as needed for conditions. On top of all of this is your outer shell. This is the wind and water repellent layer. As HVAC/R mechanics, we need this layer to be abrasion-resistant as well. Something like a down ski jacket is probably the warmest thing you can find, but they won’t last very long around those sharp sheet metal edges.

A Carhartt coat and bib overalls are great and are the standard for tradesmen everywhere, but other brands like Walls and Dickies are just as warm and can be had for less money. Personally, I prefer a bib and coat set over a set of coveralls. That way, I can wear just what I need rather than having to either be cold or wear the whole, heavy setup and maybe overheat.

Another nice thing to have is a foam kneeling pad. Not just to cushion your knees from the roof but to keep snow from melting into your insulation and making you colder.

Now let’s talk headgear. Sure, a beanie is great, but when you’ve got to be out there for hours, gotta keep the grey matter warm. My setup starts with a polypropylene fleece balaclava. They’re great because they are so versatile. They’re everything from a neck warmer to a full head, face and neck insulator. Every tech that works in cold weather needs one. When the wind really kicks up or the mercury really drops, though, that just isn’t quite enough for all-day comfort out on that roof. Enter the “Mad Bomber” hat. Big, floppy rabbit fur ears wrap the sides of your face and buckle under your chin. Now, we’re staying toasty. When the weather really gets nasty and the wind is howling, I’ll pull the hood of my coat up then wrap a pair of inexpensive ski goggles over the whole mess. The hood keeps the wind off of the back of your neck and the ski goggles both protect your eyes from the harsh snow glare, cold winds and holds the whole thing together. Best of all, ski goggles don’t fog up like regular sunglasses do.

No matter how cold it gets, I don’t like insulated boots for work. If I’m working inside, my feet get wet and sweaty and uncomfortable then, if I have to go outside I’m already wet and, once you’re wet you will get cold a lot faster. So, I stick with uninsulated boots for everyday wear and I carry 2 extra pairs of socks. A pair of polypropylene liner socks. These are the base layer for your feet. Not keeping you warm but keeping you dry. Over those, a pair of nice, thick wool socks. Lace your boots up over them and you’ll be plenty warm but there is one more step to warm feet. Spend enough time out of the roof like this and one thing happens.. your boots get all snow-packed, then the snow melts and soaks through the boots and you wind up with wet, cold feet. The answer is a pair of overboots. Pull them on over your boots, buckle them up and now your feet stay dry and warm. One quick note on boots. OSHA requires safety toe boots, but that doesn’t mean steel toes. The steel toes on those boots just stay cold, no matter that you do and it radiates what heat you’ve got in your toes and you suffer.

When boot shopping, buy safety toe boots with a composite toe. The plastic safety toe is still OSHA approved but it more comfortable to wear in the cold. One important thing is to avoid cotton. Cotton socks, cotton underclothing, etc absorbs moisture and doesn’t provide any insulation value.

Unfortunately, I don’t really have any all-day stay warm tricks for your hands. A pair of ragg wool gloves is about the best protection I’ve found. Usually, I wind up with my hands in and out of the gloves all day, balancing between keeping my fingers warm and and being able to do the job. Another nice thing to have on hand, so to speak, is a couple of packages of those disposable hand warmer packets. Unwrap one or two and throw it into your pocket. Cheap guy trick for those. If you’re only out in the cold for an hour or so, seal that handwarmer up in a zip lock and press the air out. Since they’re air-activated, removing the air stops the reaction. Open the bag back up, shake it up and it’ll start warming back up again.

In practice, this is how I’ll employ this layering system. Your situation may be different. I dress for work very much the same every day. Work pants and a T-shirt. As the weather cools, I’ll add a sweatshirt and eventually, a vest. That’s just for walking around. When the call drops that I have to go hang out on the roof, I find a place where I can change. Based on experience with in the cold, I’ll select the right amount of layers to keep myself warm without overheating. Sweating can be as bad as shivering and will ultimately lead to shivering. I keep the heavy gear packed in a big duffle bag in reverse order of putting it on, so I can just pull a piece out, put it on and grab the next piece. Peel gear off in the same order and it packs away, ready for next time. If your gear gets wet, be sure to dry it before venturing back out into the cold.

Hypothermia and frostbite

Since we generally work alone, we really need to learn to self-monitor for these two conditions. Hypothermia is a serious, potentially life-threatening condition where the body core temperature drops below 95F and the body is no longer able to warm itself. Your brain and vital organs will stop working and you will go to sleep one last time. The first symptoms of this are violent and uncontrollable shivering. This is your body working your muscles vigorously in an effort to generate heat to keep itself warm. Further symptoms include slurred speech and disorientation. Don’t ignore these symptoms and if you find yourself in that condition of violent and uncontrollable shivering, get yourself somewhere that you can warm up and stay there until you are warm.

Frostbite is the formation of ice crystals in your body. This occurs when exposed skin, typically fingers, toes, ears and noses literally freezes. It is very painful and can result in the loss of flesh in the affected area. Symptoms include pain, itchiness and discoloration of the affected part which progresses to hardening as the flesh freezes deeper. Much like hypothermia, this is much better treated early than allowing it to progress. Stop and allow the area to warm slowly. DON’T RUB IT. This breaks up any ice that has formed and those ice crystals can cause more tissue damage. Cool water is the best way to warm a frostbitten area. One last caution or two to touch on.

A lot of guys like to drink coffee, tea or hot chocolate to warm up. While I love a good, hot cup of coffee, this isn’t always the best way to warm up. Caffeine is a vasoconstrictor meaning that it causes the small blood vessels in your hands, feet and elsewhere to constrict, limiting blood flow. That can increase your risk of conditions like frostbite because warm blood isn’t flowing to those areas. Also, we typically associate dehydration with summertime and sweating, but in cold conditions, this is also a concern because the air is so dry, we’re losing moisture with every breath plus we may be sweating and the wicking layers we wear are dissipating that moisture as they’re designed to and we don’t notice the sweat like we would in the summer. Stay hydrated.

— Jeremy

Shopping list
Sportown Men’s Merino Wool Lightweight Long Sleeve Crew Base Layer Top,XXL 

Minus33 100% Merino Wool Base Layer 706 MidWeight Bottoms Black XL
Balaclava Fleece Hood – Windproof Face Ski Mask – Ultimate Thermal Retention & Moisture Wicking with Performance Soft Fleece Construction, Black, One Size

Mad Bomber Supplex Hat with Grey Fur, Black, Medium

RefrigiWear Insulated Wool Gloves Green Large

Fox River Outdoor Wick Dry Alturas Ultra-Lightweight Liner Socks, Medium, White

Wigwam Men’s 40 Below Heavyweight Boot Socks, Grey Twist, X-Large

Ski Goggles for Youth Age 8-16 ¨C UV400 Protection and Anti-Fog ¨C Double Grey Spherical Lens for Sunny and Cloudy Days (Black)

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