Landing a job in HVAC is unique because every employer has a different philosophy on professionalism. For some, the goal isn't just to look good—it’s to look capable. Here is how to balance a sharp presentation with a "ready-to-work" attitude. 1. The Logistics of Professionalism Professionalism starts long before you shake hands. Your arrival sets the tone for your reliability in the field. The Golden Rule of Time: If you’re on time, you’re late. Aim to be early. The Dry Run:

When teaching students how to use and read a tape measure for the first time, I have a go-to set of items to facilitate the training. I use 13 pieces of wood with 26 measurements labeled A-Z. Each piece has two letters, one for each dimension to be measured. I then give each student a fraction layout sheet for an inch and another sheet that they can write their answers on for each letter measured, A through Z. I explain the 1/2", 1/4", 1/8" and 1/16" fractions, full one inch

If you remove the vapor access port cap on a running air conditioning system, the low temperature brass on the inside of the port will condense water vapor from the air surrounding the port directly onto the port. This is because the air surrounding the port is often below the dew point. Don't remove the port cap until you are immediately ready to connect the gauge. Don't even connect the gauge unless you suspect a problem with the refrigerant charge level. We want to reduce

After servicing or adding refrigerant to an air conditioning system, add locking caps to the service ports if the system is in an accessible area. This reduces the chance of someone tampering with the refrigerant charge. The IMC code that requires this may or may not be adopted/enforced by your local municipality. However, it is a really good idea to do so to keep everyone safe and to keep the refrigerant charge intact. IMC Code 1101.10: " Refrigerant circuit access ports loc

There are a number of factors that lead to a residential NO A/C service call, so make sure to rule out the condensate line/switches! These switches may be wired to break either the R wire which is the 24V power to the thermostat or the Y wire heading to the outdoor unit contactor. To find such an issue, inspect the condensate area for any visual signs such as a secondary pan full of water! A simple issue like a clogged condensate trap or a clog at the condensate pump can lea

The purpose of this HVACR training project is to visually show your students the change in the amount of liquid flowing through a TXV or Piston Metering Device during operation. Using water as the liquid during this experiment helps them visually see this in action! Why does the TXV Matter? A TXV (Thermostatic Expansion Valve) can change the amount of liquid refrigerant traveling into an evaporator coil to absorb heat. This regulation device allows the system to act in an eff

When servicing an air conditioner or heat pump, we often notice a low airflow problem which needs to be fixed. If there is no indoor air filter or there is air skirting around the air filter because its not snugly fit, the dust will collect on the side of the indoor evaporator coil. Eventually, enough dust collects onto the coil to significantly reduce the amount of airflow crossing through the coil fins. This reduces energy transfer, increasing electricity bills and reducing

If you suspect that an evaporator coil is clogged with dust but cannot visually see it, such as when you can't directly inspect on a furnace and evaporator coil , static pressure measurements can be used to determine if the pressure drop is too high. This is a quick way to determine how blocked off the under side of the coil is. The higher the pressure drop, the more restricted the coil. The more restricted the coil, the lower the CFM of airflow crossing the coil. The lower t

Measuring airflow is one of the most commonly missed or ignored topics in HVAC when commissioning or diagnosing problems in systems. I don't believe this topic is purposely ignored due to lazyness or just wanting to reduce the time on service calls. I believe it actually stems from the lack of easy to follow methods, and a lack of accuracy in some methods due to either system design or tool limitations. Below are possible methods or tools to measure airflow in HVAC systems: T

Today most people are aware of the invisible, odorless, poisonous gas of Carbon Monoxide or CO for short. Now we know that even low levels of CO can have long term health effects depending on exposure time, the health and age of the exposed person. Carbon Monoxide binds with the hemoglobin in the blood 300 times more than Oxygen. It is believed that Florence Nightingale's ailments may have stemmed from CO poisoning from her coal heater in Russia. Some haunted houses were actu

Problem #1: No Power to the Package Unit On all HVAC systems, power is critical to operation, and a package unit is no different. There several reasons a package unit may lose power, but fortunately determining if this is the problem can be done fairly simply. First, remove the cover plate of the package unit to look at the control board. If the LED light on the control board is lit, there is power to the unit and the problem is something else. If the LED light is not lit, t

I just finished reading the book Unconformed, by Bryan Orr, from HVAC School. I invested about 5 hours spread over three days and let me...

(This image is courtesy of our friend JD Kelly @student_of_hvac ) In this refrigerant flow diagram, we see a simplistic piping arrangement for a heat pump running in cooling mode. When we take the complexity away, such as in this drawing, it allows a newer tech to easily follow the refrigerant path, especially as the refrigerant travels through the reversing valve and accumulator. Most of us don’t remember how overwhelming and complex things can seem when starting out in thi

(This image is courtesy of our friend JD Kelly @student_of_hvac ) This drawing shows how a low voltage wiring circuit can control a high voltage, high current load, such as a blower motor. Make sure to show this pic to your new apprentices! Remember that a thermostat acts as a simple switch. When manually turning on the fan, the thermostat connects the 24v R wire to G wire in the thermostat. The R wire is the 24 volt power wire which is typically red. The G wire is to control

This short project is designed to show how to teach thermostat operation and wiring to a newer HVAC technician or a student in a mobile and easy to understand format. This particular project covers how a thermostat controls a gas furnace and air conditioning system. This can be accomplished using only a few simple items such as a basic thermostat, a small section of 18-5 or 18-6 (18 gauge, 6 colored wires) thermostat wire wire, and a multimeter. Why Does Thermostat Training M

Explaining how an EEV operates is much easier when you can show exactly what is happening, each step of the way. This project is meant to simplify the operation of the EEV by visually showing the internal pin movement as 12V power is temporarily applied to each of the 4 electrical coils in sequence. Why does the EEV Matter? The EEV is one of the most important parts in a modern inverter system. This metering device is responsible for reducing the pressure of the refrigerant f

This training project is designed to provide a clear way to see how a pressure transducer operates and how they can be tested. Why does the Pressure Transducer Matter? Pressure transducers are typically found on commercial VRF (variable refrigerant flow) systems. These devices are used to communicate the refrigerant pressure, as a specific voltage, to the PCB. This project is designed to visualize how pressure transducers work and provide an example for how to test them. To l

This training project is designed to show how bead thermistors and tube thermistors work, along with the difference in sensitivity between the two. Why does the Thermistor Matter? Thermistors are critical to the efficient operation of modern inverter systems. They are the devices used by the system to monitor temperatures, at various locations, across the system. The electrical resistance of each thermistor (shown on each display) changes as the temperature of thermistor chan