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

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

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

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

Explaining how a louver motor operates is much easier when you can watch the louver blade move, each step of the way. This project is meant to simplify the operation of the louver motor by visually showing the louver blade movement as 12V power is temporarily applied to each of the 4 electrical coils in sequence. Why does the Louver Motor Matter? The louver motor is often an overlooked component on ductless systems. That is of course, until the unit isn't allowing the air to

This article covers the ten most common locations where refrigerant leaks may be on an air conditioning system. An electronic leak detector is typically used to find the general area of the leak and non-corrosive bubble leak detector is used to pinpoint the leak. In the following pictures, an Accutrak ultrasonic leak detector and Big Blu non-corrosive bubble leak detector are used to search for and find refrigerant leaks. A ultrasonic leak detector (see photo below) locate

Swaging tools are used to expand the end of a copper tube to accept the next section of tubing. This is done prior to making a permanent braze or solder connection. Swaging is a method used on ACR (Air Conditioning, Refrigeration) copper tubing for refrigerant as well as soft copper tubing used for plumbing. Swaging is done to reduce the amount of brazed or soldered joints in a tubing run. In the case of a coupling, two braze joints are needed, whereas with a swage, only one

Basic Characteristics of a Good Instructor "The hardest year of teaching is the one you are currently in." - Ty Branaman Based on their experience, Ty Branaman and Craig Migliaccio believe the following characteristics, strategies, behaviors, and habits make a good instructor. Tip #1: A good instructor cares. People matter to the instructor. Therefore, the instructor care

On a natural gas or propane furnace, there are typically 6 main reasons why a blower fan motor may not shut off and just continues to run. Before turning the power off to the furnace or opening the doors to the furnace, check the LED status code light (if equipped) for any error codes. On the furnace, there should be a correlating error code list. This will help in the initial diagnosis of the problem. Reason #1: One of the 24v Electrical Safety Switches Inside the Furnace H

This article explains the "Top 5 Problems" that can occur on a contactor and how to troubleshoot them! The HVAC Contactor is a device that turns on the outdoor unit compressor and outdoor fan for air conditioners and heat pumps. First, let me briefly explain what the contactor is and how it works. HVAC contactors typically come as single, double, or triple pole. This refers to the amount of poles it can switch on or off. The switching action occurs when powering the lower coi

In this HVAC training article, we will be discussing how to adjust the fan speeds on an indoor ECM variable speed blower motor and an ECM constant torque/multi-speed blower motor. These blower motor versions can be found in furnaces, air handlers, and packaged units. This is a follow-up to our other article on " Adjusting the Furnace/AC Airflow Speed on a 120v PSC Blower Motor ". If you have not read that yet, I would encourage you to do so! To start, ECM stands for Electr

This article explains how the thermocouple, gas valve solenoid, and pilot flame work on a water heater. I will be discussing 10 problems that may occur that causes the pilot flame to go out along with the solution for each example. The following steps indicate how to light the pilot on the water heater and explains the key components within the water heater that make it work. Lighting a pilot should be fairly simple. 1. Locate the large red/white knob on top of the water heat

In this HVAC training article, I discuss 20 AIRFLOW Problems that you may find on ducted gas furnaces, air conditioners, heat pumps, air handlers, and packaged units. Some problems happen over time due to lack of maintenance while others may have occurred during the initial installation. Low air flow is a big deal, so it is important to figure out what is causing this issue. For a furnace it could overheat. For an air conditioning system, the evaporator coil could freeze. If

A refrigerant leak may be easy to find when the leak is a large one but when the leak is small, finding it can be tedious and time consuming unless the right leak detection tool is used. If a leak exists in a system, the leak may be anywhere such as in the condenser, evaporator coil, line set, or a fitting, component, or joint. Searching all of these areas must be done quickly and with confidence. Regardless of the type of gas within the HVACR system, an ultrasonic leak detec

On a mini-split ductless system, two copper tubes are needed to transport the refrigerant. These copper tubes are referred to as the line set and they connect the indoor head unit to the outdoor heat pump or condensing unit. Two flare connections are needed at the indoor head unit and two flare connections are needed at the outdoor mini-split unit. Things to consider: · A standard system has four flare connections while a multi-zone system has more flare connections for the a

Pilot lights can be found on furnaces, water heaters, fireplaces, ranges, ovens and other appliances. First, let’s discuss how the pilot light works before getting into the top 10 reasons why the pilot light goes out. A pilot flame is lit with a manual push button spark ignitor or a handheld lighter while pushing down on the pilot plunger button found on the top of the gas valve. To light a gas pilot, the button on the combination gas valve must be pushed down which allows ga