Copper was the mainstay in HVAC and refrigeration coils until 2011, when copper prices went through the roof. As manufacturers began testing alternatives, the industry settled on aluminum as a workable, less costly option.
The use of ductless heat pump HVAC systems has broadened considerably since they were introduced to the U.S. market decades ago, but their technology isn’t familiar to all technicians or in all parts of the country.
Technicians should learn how to troubleshoot defrost timers, as they can be the culprit if a freezer that uses an electric heater as its supplemental heat source has a frozen evaporator coil.
A split system heat pump's defrost sensor is used to detect ice buildup on the heat pump's outdoor coil. The exact way in which a defrost sensor works can vary.
If a potential relay is malfunctioning, the compressor motor is in danger of not starting, stalling, locking rotor, or even burning out. That is why technicians should understand how to troubleshoot potential relays.
Residential HVAC system design is a foundational step in the process to deliver predictable comfort, and estimating the heat loss and gain of a dwelling is the cornerstone of that process.
Service technicians need to be careful when reading the pressure/temperature chart because if they choose the wrong values, they will make mistakes diagnosing the system.
Is performing a Manual J load calculation needed in residential retrofit applications? For the industry energy experts sitting behind a desk, yes. For those of us in the real world, it doesn't make sense.