The answer to 'why is my evaporator coil high energy bills' is that a dirty or malfunctioning evaporator coil can cause your HVAC system to use more energy. The evaporator coil is responsible for absorbing heat from the indoor air, and if it's not working efficiently, your system has to work harder to cool your home, leading to higher energy bills.
Some common causes of an inefficient evaporator coil include dirt and debris buildup, refrigerant leaks, and airflow issues. Symptoms may include warm air coming from your vents, uneven cooling, and increased humidity in your home. Resolving these issues can help lower your energy costs.