HVAC Systems and Service Flashcards

A resident reports that their air conditioning unit is running, but the air blowing from the vents is not cold. During your inspection, you notice a significant amount of ice buildup on the evaporator coil. What is the MOST likely cause of this issue?

Answer: A dirty air filter restricting airflow.

A dirty or clogged air filter is the most common cause of restricted airflow across the evaporator coil. This lack of warm air causes the refrigerant in the coil to become too cold, leading to condensation freezing on the coil's surface. While other issues can cause problems, a dirty filter is the first thing a technician should check for these symptoms.

As part of a preventive maintenance schedule for an apartment community's HVAC systems, which of the following tasks should be performed most frequently?

Answer: Inspecting and cleaning or replacing air filters.

Air filters should be inspected monthly and replaced every 1-3 months, depending on usage and environment. This is the most frequent task required to maintain system efficiency and indoor air quality. Coil cleaning, refrigerant checks, and lubrication are typically done seasonally or annually.

A resident complains of weak airflow coming from the vents in their apartment. After confirming the air filter is clean, which of the following is the next logical step in troubleshooting the problem?

Answer: Checking for blocked or closed supply and return vents.

After checking the air filter, the next step is to ensure that vents and registers are not blocked by furniture, rugs, or other items, and that the dampers are open. This is a simple but common cause of poor airflow that can be quickly identified and resolved.

When handling refrigerants during HVAC service, a CAMT must adhere to specific safety and environmental protocols mandated by the EPA. According to the Clean Air Act, what is strictly prohibited?

Answer: Intentionally venting refrigerant to the atmosphere.

Section 608 of the EPA Clean Air Act prohibits the intentional release (venting) of refrigerants into the atmosphere during maintenance, service, repair, or disposal of HVAC equipment due to their harmful effect on the ozone layer. Technicians are required to recover the refrigerant using proper equipment.

You respond to a work order for an HVAC unit making a loud banging or clanking noise during operation. What is the most probable cause of this specific sound?

Answer: A loose or damaged component, such as a blower fan blade or motor mount.

Loud banging, rattling, or thumping noises typically indicate that a mechanical component has become loose, broken, or is out of balance. This could be a problem with the blower wheel, fan blades, motor, or another moving part inside the unit.

To ensure the outdoor condenser unit functions efficiently, what is a critical, routine maintenance task a CAMT should perform?

Answer: Ensuring the area around the unit is clear of leaves, debris, and vegetation.

The condenser unit transfers heat from the refrigerant to the outside air. Its efficiency relies on unrestricted airflow. It's essential to keep the area around the unit clear of obstructions like leaves, grass, bushes, and other debris that can block airflow and cause the system to overheat and lose efficiency.