Most homeowners view HVAC as a "black box" in their attic or basement. You can build massive authority by pulling back the curtain. Instead of selling a unit, sell indoor air quality (IAQ) or efficiency.
Tip: Show "Before & After" photos in an appointment or social media of disgusting filters or clogged coils to trigger a "could that be mine?" response.
Why it works: It shifts the conversation from a grudge purchase (repair) to a health and wellness investment (clean air).