Joey Henderson, an HVAC instructor with more than 30 years in the industry, and Nick Goode from iConnect Training use the TU-406C Residential Heat Pump Trainer to teach six key lessons to students.
Lesson #1: Importance of the Condenser Fan Mode
As the residential heat pump unit is turned on, the indoor fan starts blowing and pulls air through the return. Have a student feel the air with a piece of paper. As it pulls the air in the return box, the evaporator is absorbing the heat. Then, it takes that heat and absorbs it into the refrigerant and goes to the condenser. It has to discharge all that heat and refrigerant out of the condenser. If a student puts their hand over the top of the condenser, they can feel the hot air coming out.
Now, what happens if the condenser fan mode is off? View the normal operating pressures and flip the condenser fan mode off. Ask the students what they think will happen and why. Watch as the pressures go up.
Lesson #2: What Heat Transfer Actually Is
As the gauges are going and fans are running, turn the outdoor fan off and notice that the pressure goes up. Why is that? Because air is no longer being pulled across the coil. Now, the heat stays in the refrigerant and just cycles back through.
When the outdoor fan is turned back on, watch the hot air blast out of the top. That’s actually the heat transfer. Also, measure the return air coming into the unit and the supply air leaving the unit using the temperature sensors to discuss sensible and latent heat with the students.
What happens if the indoor fan is turned off? The heat transfer changes there as well. The coil starts getting colder because it’s not absorbing heat.
Lesson #3: Difference on the Traps
The condensate trap is on the intake side of the blower motor. Explain to the students the importance of a deep enough trap so that water is not pulled back up as it starts filling up with water.
This is a common trap on a lot of air handlers and has a safety in it. If the trap begins to plug up and no longer drains water, the safety will turn the system off before it fills up with water and spills out into a conditioning space in the basement or in the drain pan. There’s also a safety switch in the drain pan.
When it’s summer time, open the windows and let the humidity in. Students will see the coil build condensation and the water start to build up in the drain pan through the plexiglass.
Look for part two next month 👀
Easily Demonstrate the Components of a Residential Heat Pump Unit with the TU-406C
Our residential heat pump simulator makes it easy to demonstrate Joey’s lessons. Download the training unit’s spec sheet or give us a call today at 716-699-2031 to request a quote.