- Tech Tips
This is Part 3 series by Senior Refrigeration Tech (and prolific writer) Jeremy Smith. Pay attention to this one folks, I know rigging and safe lifting practices may be boring to some of you, but it could very well save your back or your life.
This article is written by a technician representing his real-world experiences and his advice for best practices. You MUST understand the particular application, weight of materials and load strength of every item you use. From struts, to pulleys, to anchors, ladders, ropes etc.. HVAC School is NOT giving OSHA approved safety advice. Refer to your managers, safety professionals and OSHA guidelines first and foremost. Apply any and all of these practices at your own risk with the knowledge that we are trying to help keep you from hurting (or killing) yourself.
Now that we have a basic understanding of how to handle ropes, tie knots and rig a basic pulley system, we’re ready to dive into more complicated systems. I reserve these for buildings that have a roof hatch so that I can setup a gantry over the hatch. I haven’t yet figured out a system to extend a beam over the edge of a building, but I’m working on it. I’ll go into the basics of how I build and what I build in the next section. For now, let’s just accept as a given that we have a solid beam installed over the hatch opening to connect ropes
and pulleys to.
For jobs like this, I keep a double pulley on the truck. Threading or ‘reeving’ these takes more time and is more complicated but the reduction in effort is worth it. Start by fixing your single pulley to the overhead beam and connecting the double one to a light “load” like a wrench or something similar. Tie one end of the rope to our overhead beam. Start threading by running the other end through one side of the double pulley then through the single, through the other side of the double. Now, you should have a nice mess of rope. Lower that weighted double pulley to the spot where the load is and secure the free end of the rope with a clove hitch just to keep it from falling and to keep a tiny amount of tension on the system.
The setup shown here was used to hoist a 15 hp blower motor onto the roof. Motor weight was something like 145# With 4 lines supporting the load, the effort to hoist that motor was less than
I like to stand on the roof while hoisting, so I make it a point when threading pulleys to wind up with the pull end of the rope going up. This also has the advantage of using every line to support the load and obtaining maximum effort reduction.
As before, connect to the load and hoist it slightly. Check for good balance, twisted ropes and crossed lines. Make any corrections and hoist away. Since we’re hoisting to an overhead beam, there won’t be any need to take 100% of the load at any time, so this method is much safer and, when we dig into the gantry build, we’ll find a great way to manage the load once it’s at the top of the lift. As the loads get heavier, you’ll be using heavier and heavier duty hardware to attach to them. Eye bolts, shackles and chains are the rule here.
Crosby 1018393 Carbon Steel G-209 Screw Pin Anchor Shackle, Galvanized, 3/4 Ton Working
Load Limit, 5/16″ Size
This is Part 2 series by Senior Refrigeration Tech (and prolific writer) Jeremy Smith. Pay attention to this one folks, I know rigging and safe lifting practices may be boring to some of you, but it could very well save your back or your life.
This article is written by a technician representing his real-world experiences and his advice for best practices. You MUST understand the particular application, weight of materials and load strength of every item you use. From struts to pulleys, to anchors, ladders, ropes etc.. HVAC School is NOT giving OSHA approved safety advice. Refer to your managers, safety professionals and OSHA guidelines first and foremost. Apply any and all of these practices at your own risk with the knowledge that we are trying to help keep you from hurting (or killing) yourself.
Let’s get into the meat of lifting and moving heavier loads…
One thing that I use a LOT is a basic pulley. Simply put, when using a pulley or a system of pulleys called a Block and Tackle, the amount of force required to lift a load is the total weight divided by the number of lines supporting the load. An overhead pulley system doesn’t reduce lifting force at all. It does nothing more than redirect the force applied. Since there is only one line supporting the load, there is no reduction in force required to lift the load.
A pulley connected to the load with one line tied off and pulling force exerted on the other end of the rope will cut the force required in half for lifting a load. Here, with 2 lines supporting the load, the force or effort required to lift the load is cut in half.
In practice, I limit this to loads of 50-100 pounds or so because at the end of the lift, you will be lifting 100% of the weight. For your first couple lifts, try to stay on the lower end of these weights until you build confidence in your techniques. We’ll get into more complicated systems with more pulleys and lines in a later section.
Start by tying off one end of the rope to something secure. This is your anchor point. Best case scenario, there is something they’re purpose-built to anchor to. Worst case scenario, I’ve actually tied a loop around the entire curb assembly of a rooftop unit.
Remember, use good knots. The ONLY knot that I trust in this situation is a bowline. Now that we’ve got our rope anchored, slide the pulley onto the rope and lower that pulley to your load. Tie the other end, the lifting end, of the rope off to something, anything really. A clove hitch is quick and easy here. All we’re doing is keeping the rope in place so it doesn’t fall. To connect the pulley to the load, I like to use a climbing carabiner with a screw lock. Cheap carabiners that you can get at most home improvement Warehouse stores are NOT suitable here. If all they do is bend under the load, count yourself lucky.
If there is a lifting eye or provision to install one on the load, use it and be sure to lock the eye bolt in place with the included nut, otherwise, the load can unscrew itself from the bolt and fall. That is going to be the best and safest place to connect your pulley to the load. Now, back up to the roof and take a couple seconds to straighten out the ropes. Get any twists out of the system and lift the load a short distance off the ground. Check everything. Is your anchor solid? Are you comfortable with the load? If everything is good and you’re comfortable with the lift, then continue pulling the load up to the roof edge.
Remember when I said to limit the weight? Now you’ll see why. You’ve got the load almost there…. You’re going to have to squat to the load, grab it and haul it over the roof edge. Yeah, it sucks but not as bad as hauling the whole load all the way up the side of the building. This is where a carabiner is nice because that big metal loop gives you a solid handle to grab
and hang on to.
P.S. – Today’s Shopping list
This is an open letter sent to staff at Kalos Services
First, I want to remind you that you are in no way obligated to read company emails or do anything work related when you aren’t working. So if you don’t want to be bothered by this on your day or time off then by all means save it and get back to it during work hours.
At Kalos we do a lot of training and developing people towards their goals. It always has been and always will be a big part of what we do.
Lately, I’ve had a lot of people stop me and say some version of “I would really like to learn about _________ (fill in the blank)”
Can I sit in on a few of your classes it seems really interesting?
What classes or certifications can I get / take to help me advance?
When I ask what they are already learning about the subject there usually isn’t much.
You aren’t going to like this answer, but it’s the truth.
If you haven’t already started learning something on your own then I’m not going to be much help.
I make 2 podcasts, 2 videos and send out 3 to 7 tech tip emails per week about all sorts of topics related to HVAC.
There are only a few of you who pay any attention to what I already make to help train you.
It isn’t just me, there are tons of books you can read, free videos you can watch, manufacturer manuals you can reference, online forums and groups you can leverage, code books you can refer to etc…
Before you start feeling defensive let’s be clear.
Most of you work a lot and watching videos or reading or listening to podcasts about AIR CONDITIONING of all things just isn’t a priority.
I get it…
But that means that you like the idea of learning or the recognition that comes along with showing an interest in learning but do you really want to learn?
Of course we all learn hands on doing our jobs. We learn from our mistakes, we learn from whomever we work with… that is all a type of learning that is forced upon on us and often it is valuable.
That is learning by force rather than by choice and you can do very well learning in that way.
When I started teaching classes in my 20’s I was an idealist. I thought everyone would be interested in knowing everything they could about their jobs and the world around around them. I figured they would take advantage of free education provided to them to advance in their careers.
That just isn’t how it works
Most people want to FEEL like they are interested in learning or growing but they actually only learn or grow when their circumstances force them to.
Most people like the sound of “opportunity” but when opportunity looks like reading a boring book or manual then they look for a different opportunity.
So you may be feeling a bit like “what’s your point?!” Or “This dude is a real jerk”
People who know me best know that deep down I am a bit of a jerk and that that I also really care about seeing you all grow.
The point is this –
If you really want to learn you will start by learning without being forced to learn. If that’s you than I would be thrilled to help you along that journey.
Otherwise you will still learn by circumstances and if you are a talented, hard working, good person you will still have a home at Kalos whether you like learning or not.
However, there is no point in attending classes (other than ones directly related to your current role) or asking me about how you can learn more or progress. I can’t force you to learn and a few classes will only stand to create more confusion.
If you (actually) want to learn more about the HVAC/R trade then by all means, start down that path and I will be thrilled to help you along the way, give you classes, send you to classes, help you find resources etc…
But if you walk up to me or email me and say you want to learn be prepared for me to ask you what you’ve already been learning.
A job is something you are given to do and you do it.
A career is something you create with intention and investment in yourself.
Thank you for all of hard work and I truly appreciate every one of you. No matter how you learn or the job you do.
This is ANOTHER series by Senior Refrigeration Tech (and prolific writer) Jeremy Smith. Pay attention to this one folks, I know rigging and safe lifting practices may be boring to some of you, but it could very well save your back or your life.
This article is written by a technician representing his real world experiences and his advice for best practices. You MUST understand the particular application, weight of materials and load strength of every item you use. From struts, to pulleys, to anchors, ladders, ropes etc.. HVAC School is NOT giving OSHA approved safety advice. Refer to your managers, safety professionals and OSHA guidelines first and foremost. Apply any and all of these practices at your own risk with the knowledge that we are trying to help keep you from hurting (or killing) yourself.
I know, I know… everyone is super strong and nobody needs any help lifting those big, heavy compressors and motors. At least that’s what a guy could think if he just reads the HVAC pages
Reality check. If you’re lifting anything over 50 pounds and are not using a mechanical device to do it, you’re risking serious injury. I speak from experience here. In 2016, I spent 16 weeks off of work progressing from Chiropractic care to physical therapy and ultimately had to have surgery to repair a herniated disc. The injury resulted from a twisting motion when a 200lb compressor we were throwing into a scrap bin went sideways and started to fall on me. I caught it but I didn’t avoid a painful injury…
Hopefully, I’ll be able to share more than a few tips, tricks and techniques to help you work more safely and more effectively and inspire you to learn more about this subject. By no means should this be taken as a comprehensive treatment of the subject of lifting and rigging, but just a primer with some cautions and warnings and the advice to go slow and always, ALWAYS double check yourself **before you wreck yourself** (**Added by Bryan in editing… because he’s a child)
Let’s lay down some baseline rules. Not to be “preachy crossfit guy” but keep your core strong. Sometimes, you just have to gut it out and move a heavy thing. Those core muscles are what prevent injury when your body goes outside of your normal range of motion and, if they aren’t strong, they can’t support your spine and skeletal system and that’s when you get injured.
Also, when you just have to lift using body strength, use proper techniques. We all know the words “Lift with your legs, not your back” but how many of us actually DO? I can tell you for 100% certain that any time I’m moving to lift something, I’m using proper techniques whether it’s a refrigerant drum or a screwdriver I dropped. Now get down and give me 20 squats!
As we get into the application of ropes and pulley systems, we will be tying knots. Knot tying can be a very involved topic but you can do everything were going to be doing with the bowline and the clove hitch. If you can’t tie either of those knots, here are links to simple videos that illustrate how to..
If you attempt any of these techniques with inferior knots, you run a very real chance of losing control of that load and injuring yourself or someone else and damaging that expensive part.
Another thing to take a bit of time to learn about is basic rope care. A knotted, twisted rope isn’t as easy to set up and you’ll waste time dealing with twists, knots and tangles. Learn to coil and stow your rope well and this stuff will be a lot easier.
A quick note on rope. Buy good rope. Avoid the 3 strand twisted rope. It’s stretchy and the ends unravel and are difficult to manage. What you want is called Kernmantle rope. This is the type of rope that has a kind of braided “sheath” over inner fibers. It’s stronger, doesn’t stretch and it rides much easier through pulleys. Burn the ends well to prevent them from getting out of control.
One final note. Wear a decent pair of relatively snug fitting gloves while hoisting and lowering loads with a rope. If that rope starts to slide, the burns you will get on your hands take a long time to heal.
Now, basics covered, we can move on to actually lifting things.
P.S. – Here is a good rope ROTHCO UTILITY ROPE 3/8” 100 FT / OLIVE DRAB
If you do any larger commercial work you’ve probably seen a DIN rail without knowing what it is called. It is simply a mounting standard that originated in Germany in the 80’s and slowly worked its way over here.
DIN rails can be used to mount terminal blocks, relays, starters, breakers… just about anything electrically. They aren’t designed to conduct electricity like a busbar, though they are used in some cases as a grounding assembly.
The most common DIN rail type is the “top hat” or TS35 shown in these photos.
Components that attach to a DIN rail have little release clips so that they can be easily installed and removed. In addition to the “top hat” style there are also some less common, heavier DIN rails with a C and G style configuration.
So if you ever see one of these don’t be alarmed, you can just sound cool when you call your boss and tell him “yeah, it’s one of those DIN rail mounted relays” and just wait for him to say “What??”
P.S. – There are Two Incredible Giveaways going on right now that you should signup for. Air Oasis is giving away a bi-polar and a Nano air purifier and you can signup HERE. Also my buddy Corbett Lunsford from Home Diagnosis TV is launching a new building performance mastermind course and giving away a TON of HVAC tools HERE
If you are young and new to the trade, we need you, but if you aren’t thoughtful you might get fired.
No offense, millennials often just have a different way of looking at work than their GenX bosses and trainers.
Here are my 8 top tips to help you make it a great a career.
#8 – Act interested (even when you aren’t)
I know sometimes your trainer can be boring, but when he is talking, look alive. Literally… I’ve seen apprentices who I wondered if they were actually dead… smelly… unresponsive… you get it.
When someone is attempting to invest in you it’s important that you listen up and pay them the respect they deserve.
#7 – Learn the names of basic tools
I know it can be confusing if you are new but read up enough so that when your trainer asks for “channel locks” you don’t say “what’s that”. This isn’t difficult to do and if you want to get familiarized with some tools you can look through the HVAC School tool list
#6 – Keep the music off and the earbuds out
Work isn’t the time to be distracted for any reason. That is unless you are listening to the HVAC School podcast… then it’s OK
#5 – Ask questions and listen carefully to the answers
Listen more than you talk. Give eye contact when your manager or trainer is speaking. If you don’t understand something be specific about the part you aren’t grasping.
#4 – Repeat back what you heard
Say “I want to make sure I understood you correctly” and repeat back what you understood rather than saying OK if you didn’t fully understand
#3 – Look professional
I don’t care if your boss or trainer looks like a slob, YOU dress according to the company policy and come to work looking well kept. Obviously, you need to dress job appropriate but people naturally respect someone who has a professional appearance.
#2 – Show up on time
Show up 15 mins early. Show up 30 minutes early! This isn’t complicated and bad traffic isn’t a valid excuse.
#1 – STAY OFF YOUR PHONE
Your friends, Facebook, Snapchat… they can all wait. Give your work your full attention while at work
Oh… and while you’re at it… get good at working on and installing HVAC/R systems. That helps as well.
Enthalpy is easy… it’s just a state function that depends only on the prevailing equilibrium state identified by the system’s internal energy, pressure, and volume. It is an extensive quantity. Simple.
Like most things, the scientific definition is as clear as mud. In HVAC/R we use enthalpy measurement to come up with the total heat change in a fluid, whether it’s refrigerant, water or air.
That total change in heat content or enthalpy change is called Delta H (ΔH) which is just another way of saying “total heat split” and it is generally measured in BTU/lb in the US.
In air, we need to use probes that measure humidity and temperature like the HUB2 probes shown above or the Testo 605i probes in order to calculate the enthalpy of the air. Air has both the energy associated with the temperature of the air as well as the latent heat stored in the water vapor.
If you want to use the ΔH to calculate the total heat added or removed from the air you would then use this formula to calculate BTUs of heat added or removed from the air.
Total Heat = (H1-H2) x 4.5 x CFM
In the case above it would be
Total Heat = (29.68 – 22.77) x 4.5 x 730 (CFM we measured)
29.68 – 22.77 = 6.91 ΔH
6.91 x 4.5 x 730 = 22,699.35 BTU/hr
This total air enthalpy change is a required part of calculating total system capacity and is a pretty simple thing to understand.
Don’t confuse ΔH (Total Heat Change) with ΔT (Temperature Difference). ΔH includes both latent and sensible heat and is a measure of heat quantity in BTU/lb while ΔT only calculates temperature difference and isn’t converted to BTUs at all.