How to let scent machine work together with your hvac,
Solution:
1. Drill one hole in hvac duct
2. put metal probe into that hole,seal it
3. Set up time for scent machine 0:00-23:59 Mon..sunday.
 
Note: When it connect power,air switch will preapre 30s.then when have wind in your hvac system.,
              scent machine will work;