Final answer:
The component that uses induction to modify voltage levels for HVAC applications is a transformer, which can either step up or step down voltages.
Step-by-step explanation:
The component that uses the properties of AC induction to step up or step down voltage for particular HVAC applications is a transformer. Transformers are essential devices in the electric power industry and are used to adjust voltages to suitable levels for various applications. By exploiting the principle of magnetic induction, a transformer can increase voltage (step-up transformer) for long-distance transmission or decrease voltage (step-down transformer) for local distribution and use within homes and businesses. The coils visible within a transformer play a crucial role in this process as they are the medium through which voltage is transformed, utilizing Faraday's law of induction.