What is the fine-grained topic of the following text: Maintaining a clean HVAC system and providing proper filtration control (PUR CURx® filters and treatment using PUR CURx® ultraviolet lights) will reduce the risk in airborne contaminates in your home and will provide a clean PURAIR® environment. Only return the topic.
Maintaining HVAC system cleanliness and air quality with PUR CURx® filters and ultraviolet lights