The main way that HVAC dealers promote their services is that a well-serviced HVAC unit will make a big difference in your electric bill:
http://youtu.be/A0WcLXf1dSc
http://youtu.be/OZRYB1-taZI
http://youtu.be/cgS5oRtLHmQ
 
Of course, the drawback to this approach is that EVERYONE already does this.
 
This company did a nice job of making their spot personal. It’s a good way to make your potential client stand out from the clutter:
http://youtu.be/mgnkAq5wBak
 
Here’s an example of selling the value of the experience and credentials of an HVAC company:
http://youtu.be/LcGnYr-5WHc
 
This is a spot for AC services, but is pretty humorous and could be an effective spot as we get closer to summer time:
http://youtu.be/D2s9R9A0SBM